FATEPEN Vol.II Users Guide 1 .pdf

FATEPEN

Fast Air Target Encounter Penetration

Version 3.0.0 Terminal Ballistic Penetration Model

Volume II—User’s Guide

Prepared by:

Jerome D. Yatteau Richard H. Zernow Gunnar W. Recht

Karl T. Edquist

Applied Research Associates, Inc.

10720 Bradford Road, Suite 110

Littleton, Colorado 80127-4298

Distribution of FATEPEN is limited to U.S. Government Agencies and their contractors only.

Requests for FATEPEN must be referred to the Commander, NSWCDD, Dahlgren, VA 22448-5100

This Page Left Blank Intentionally

PROJECT 4714

FATEPEN (Version 3.0.0)

TERMINAL BALLISTIC PENETRATION MODEL

Volume II – User’s Guide

Prepared by:

Jerome D. Yatteau Richard H. Zernow Gunnar W. Recht

Karl T. Edquist

Applied Research Associates, Inc.

10720 Bradford Road, Suite 110 Littleton, Colorado 80127-4298

Prepared for:

Naval Surface Warfare Center, Dahlgren Division 17320 Dahlgren Road

Dahlgren, VA 22448-5500

Under CBDCOM Contract # DAAA15-94-D-0005, D.O. 0073

Revised October, 2003 i

FOREWORD

Preparation of the FATEPEN (Version 3.0.0) manuals was funded by the Naval Surface Warfare Center (NSWC), Dahlgren Division, under U.S. Army CBDCOM Contracts DAAA15-94-0005 (Delivery Order 73) and DAAM01-97-D-0013 (Delivery Order 33). Mr.

David L. Dickinson of NSWC, Dahlgren Division provided technical oversight for Delivery Orders 73 and 33.

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TABLE OF CONTENTS

Section Page FOREWORD .........................................................................................................................i

1.0 INTRODUCTION................................................................................................... 1-1

1.1 EXECUTIVE SUMMARY ........................................................................... 1-1

1.2 EVOLUTION OF THE FATEPEN USER INTERFACE.............................. 1-2

2.0 INSTALLATION INSTRUCTIONS......................................................................... 2-1

3.0 USER INSTRUCTIONS ........................................................................................ 3-1

3.1 STARTING FATEPEN/CVAT..................................................................... 3-1

3.2 OVERVIEW OF PRIMARY SCREEN OPTIONS....................................... 3-2

3.3 FILE COMMANDS ..................................................................................... 3-3

3.3.1 Load Parameters ............................................................................ 3-3

3.3.2 Save Parameters ............................................................................ 3-6

3.3.3 Save Results................................................................................... 3-9

3.3.4 Print Results.................................................................................. 3-13

3.4 EDIT OPTIONS........................................................................................ 3-14

3.4.1 Penetrator Parameters ................................................................. 3-14

3.4.2 Target Array Parameters .............................................................. 3-29

3.4.3 List Parameters............................................................................. 3-49

3.5 VIEW PARAMETER AND RESULTS ...................................................... 3-59

3.5.1 Penetrator Parameters ................................................................. 3-60

3.5.2 Target Array Parameters .............................................................. 3-60

3.5.3 List Parameters............................................................................. 3-63

3.5.4 Damage File.................................................................................. 3-64

3.5.5 List Parameter File........................................................................ 3-66

3.5.6 CV Table ....................................................................................... 3-67

3.6 DISCARD MENU OPTIONS .................................................................... 3-69

3.7 RUN MENU OPTIONS............................................................................. 3-70

3.8 HELP MENU OPTIONS........................................................................... 3-75

3.8.1 About FATEPEN........................................................................... 3-75

3.9 EXIT FATEPEN........................................................................................ 3-76

4.0 COMPONENT VULNERABILITY .......................................................................... 4-1

4.1 PRE-PROCESSING ANALYSIS................................................................ 4-1

4.2 CRITICAL COMPONENT SELECTION AND ANALYSIS ......................... 4-2

4.3 BASIC DERIVATION OF PK/H FORMULA - COMPKILL APPROACH ...... 4-3

4.3.1 Derivation of the Denominator ........................................................ 4-3

4.3.2 Derivation of the Numerator............................................................ 4-4

4.3.3 Neglected Faces of a Component .................................................. 4-4 iv

TABLE OF CONTENTS

Section Page

4.4 DERIVATION OF PK/H FORMULA - TRAJECTORY ANALYSIS APPROACH4-4

4.5 IMPLEMENTATION OF COMPONENT VULNERABILITY WITHIN

FATEPEN................................................................................................... 4-5

4.5.1 Defining Defeat Criteria .................................................................. 4-6

4.5.2 Defining Grid Parameters ............................................................. 4-14

4.5.3 Defining Face Areas ..................................................................... 4-15

4.6 VIEWING COMPONENT VULNERABILITY PARAMETERS .................. 4-16

4.7 RUN MENU OPTION............................................................................... 4-17

5.0 SAMPLE CASES................................................................................................. 5-21

5.1 OUTPUT NOMENCLATURE ................................................................... 5-21

5.2 SAMPLE CASE NUMBER ONE - FATEPEN DEFAULT

PARAMETERS ........................................................................................ 5-22

5.3 SAMPLE CASE NUMBER TWO - MISSILE BATTERY

PARAMETERS - COMPKILL APPROACH ............................................. 5-23

5.4 SAMPLE CASE NUMBER THREE - MISSILE BATTERY

PARAMETERS - TRAJECTORY ANALYSIS APPROACH..................... 5-32

5.5 SELECTION OF METHOD - COMPKILL VS. TRAJECTORY

ANALYSIS................................................................................................ 5-34

5.6 ARBITRARY FRAGMENTS..................................................................... 5-35

6.0 SOFTWARE DESIGN AND STRUCTURE ........................................................... 6-1

7.0 REFERENCES...................................................................................................... 7-1 v

LIST OF FIGURES

Figure Page

3-1. Basic FATEPEN Penetrator Shapes and Orientation Angles ............................. 3-19 3-2. Flat-Nosed and Round-Nosed Cylindrical Penetrators ....................................... 3-20 3-3. FATEPEN Right-Hand Coordinate System......................................................... 3-23 3-4. Overall View of Pitch, Yaw, and Roll Rotations................................................... 3-24 3-5. Sequential Pitch, Yaw, and Roll Rotations.......................................................... 3-25 3-6. Change in Presented Area of a Cylinder, L/D=1,L=0.2128-inch, with Yaw Angle .................................................................................................... 3-26 3-7. Penetrator/Target Impact Angle .......................................................................... 3-28 3-8. Plate Thickness and Fluid Thickness (Infinite lateral Extent Plates)................... 3-33 3-9. Fluid Thickness for Finite Lateral Extent Plates .................................................. 3-34 3-10. Overall View of Pitch and Yaw Rotations............................................................ 3-35 3-11. Sequential Pitch and Yaw Rotations ................................................................... 3-35 3-12. Height and Width Plate Measurements............................................................... 3-36 3-13. X, Y, and Z Plate Coordinates............................................................................. 3-37 3-14. Laminated Plate Construction ............................................................................. 3-46 4-1. Comparison of CompKill (Left) and Trajectory Analysis Approaches

(Right).................................................................................................................... 4-5 4-2. Imaginary Grid Placed in Front of Target ............................................................ 4-14 5-1. Predicted Kinetic Energy Required to Kill the Missile Battery within

10 minutes as a Function of the Distance between the Missile and the Target. Impact against the Side of the Battery............................................. 5-24

5-2. Predicted Kinetic Energy Required to Kill the Missile Battery within 10 minutes as a Function of the Distance between the Missile and the Target. Impact against the Top or Bottom of the Battery............................................................. 5-24

5-3. Threshold Kill Level Predictions for Missile Battery Sample Case...................... 5-30 5-4. Continuity and Cell Damage Kill Threshold Predictions for the Missile Battery

Sample Case Compared with Test Data............................................................. 5-31 5-5. Contour Lines Showing Missile Battery Kill Probability Level Predictions for the Missile Battery Sample Case ........................................................................ 5-32 5-6. 155-mm Shell Fragments. ................................................................................... 5-38 5-7. Cut 155-mm Shell Fragments. ............................................................................ 5-39 vi

LIST OF TABLES

Table Page

Table 3-1. FATEPEN Penetrator Materials and Typical Brinell Hardness Values ........ 3-18 Table 3-2. Catalog of FATEPEN Armor Piercing Projectiles......................................... 3-22 Table 3-3. FATEPEN Target Materials and Typical Brinell Hardness Values .............. 3-32 Table 5-1. Missile Battery Target Parameters - CompKill Approach............................. 5-25 Table 5-2. Component Vulnerability Table for Missile BatterySample Case -

CompKill Method ................................................................................................. 5-30 Table 5-3. Missile Battery Target Parameters - Trajectory Analysis Approach ............ 5-33 Table 5-4. Component Vulnerability Table for Missile Battery Sample Case -

Trajectory Analysis Method ................................................................................. 5-34 Table 5-5. Comparison of Run Time Statistics for Samples Two and Three ................ 5-35

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SECTION 1.0

INTRODUCTION

1.1 EXECUTIVE SUMMARY

FATEPEN (Fast Air Target Encounter Penetration) is a set of fast running algorithms that simulate the penetration of spaced target structures by fragments, long rods, and projectiles impacting at speeds up to about 5 km/sec. The model predicts penetrator mass loss, velocity loss, trajectory change, and tumbling throughout a target. The mass loss model includes impact fracture calculations that, depending on the impact conditions, can transform an incident intact warhead fragment into an expanding, multi-particle debris cloud which FATEPEN then tracks through the remaining target structure. FATEPEN also predicts impulsive loading and hole damage to plate structures by single penetrators and multi-particle debris clouds. The primary application of the code has been weapons effectiveness assessments involving air targets and lightly-armored surface targets.

The current development version of FATEPEN is a 32-bit FORTRAN PC code with a Visual Basic graphical user interface. FATEPEN uses the Compaq Visual Fortran1 Professional Edition, Version 6.1A, FORTRAN 90, compiler and runs under Windows 95 or higher. The terminal interaction models are compiled as a separate Dynamic Link Library (DLL) for easy portability to other calling programs. The current PC version of the code (Version 3.0.0) contains 14,176 lines of FORTRAN and 16,550 lines of Visual Basic. Typical run times with a 166 MHz PC are on the order of 0.02 second for a fragment penetrating a spaced target array comprised of about 10 elements.

The steady improvement and extension of FATEPEN has been the unifying focus of many otherwise independent experimental and analytical efforts to investigate and model high velocity and hypervelocity penetration characteristics for a wide variety of penetrator and target materials and structures. These individual studies and the corresponding FATEPEN improvements are described in detail in the technical reports and papers referenced herein.

The FATEPEN (Version 3.0.0) model and computer code is documented, in its entirety, in three volumes as follows:

Volume I – Analysts Guide. The Analysts Guide describes the analytical foundation of FATEPEN and serves to promote more informed decisions regarding its application, to aid in interpreting the output of the code, and as a reference for future improvements. This volume briefly summarizes the development history of FATEPEN, describes the penetration phenomenology addressed by the code, provides an overview of the model, describes penetrator and target input conventions, and summarizes each of the primary terminal interaction models and algorithms including the principal formulas and the assumptions and limitations associated with their development.

Volume II – User’s Guide. The User’s Guide provides instructions regarding installation of FATEPEN onto a PC, how to activate the code, and includes detailed instructions explanations, and screen displays describing how to use of the code for penetration problems and for component vulnerability analysis. Sample problems are presented to illustrate use of the code and to provide test cases to check installation of the program.

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Volume III – Validation Document. The Validation Document presents the results of comparisons between FATEPEN model predictions and numerous test results contained in an expandable terminal ballistics database. The database encompasses a wide range of encounter conditions to thoroughly test the model. Two kinds of comparisons are presented. The first type are “point-by-point” comparisons wherein the exact encounter conditions (impact speed, orientation, impact obliquity, etc.) for a particular test are input to FATEPEN and the predicted results are compared with the corresponding test results. The point-by-point comparison results establish the expected prediction accuracy of the code for various applications (e.g., long rods vs. thick plates, cubes vs. thin plates, etc.). The second kind of comparison deals with variations in model predictions and test results with changes in a single encounter variable such as impact speed, impact obliquity, etc. These “trendline” comparisons reveal basic terminal ballistic penetration behavior and are useful in design and in interpreting weapons effects results. The juxtaposition of model prediction trends and corresponding test results also serve to confirm the reasonableness of the model predictions even when the point-by-point accuracy statistics might suggest otherwise. Taken together, the two types of comparisons provide a complete picture of model suitability for specific applications.

This Volume contains the FATEPEN User’s Guide.

1.2 EVOLUTION OF THE FATEPEN USER INTERFACE

The original version of this software, called FATE (Fast Air Target Encounter), was developed in 1982 under the sponsorship of the Naval Surface Weapons Center/ Dahlgren Division (NSWC/DD)2. It was developed using the HP-BASIC interpreted language and was designed to run on an HP-9845B desktop computer. There was no “user interface” with this program. When the user wanted to make changes to the input parameters, it was a simple matter of making changes to DATA statements within the code. As HP-BASIC was an interpreted language, and the input parameters were relatively simple, this presented very little problem for the user. Output results were sent directly to a printer.

The BASIC version of FATE was translated into FORTRAN at NSWC/DD for purposes of exercising it on their VAX3 computer as well as embedding it into the air target vulnerability analysis program known as COVART (Computation Of Vulnerability Areas And Repair Times). Due to the compiled nature of FORTRAN, a text-menu based user interface was added to FATE, greatly enhancing its usability. The translated version of the code was called FATEX4.

In 1985, FATEX was converted from VAX FORTRAN to Microsoft FORTRAN5, Version 3.51 to enable it to run on a personal computer running the MS-DOS6 operating system. The converted code was renamed back to the original name, FATE. The text-menu based user interface developed for the VAX version of FATEX was maintained during this conversion.

In 1988, FATE was merged with FPIIM7, an improved version of the original PENBAM code8 to predict fragment penetration and impact initiation of cased munitions, and the combined code was renamed FATEPEN9. Since 1989, FATEPEN has been continuously improved and expanded under sponsorship by NSWC/DD, other government laboratories, and private industry An integral part of these improvement efforts has been expansion of

1-3 the FATEPEN user interface to include new options. However, until the current study, the basic design of the user interface has remained the same.

The FATEPEN/CVAT graphical user interface described herein was developed using Microsoft Visual Basic10, Version 4.0 Professional Edition. Microsoft Visual Basic, Version

4.0 could operate in either 16-bit mode (Windows 3.XX or Windows 95) or in 32-bit mode (Windows 95 or Windows NT). The FORTRAN code was compiled using Microsoft Powerstation 4.0 Professional, a 32-bit compiler.. To communicate with the FORTRAN DLL created by PowerStation, Visual Basic development was carried out in 32-bit mode.

Currently, development of the FATEPEN/CVAT graphical user interface is continuing using Microsoft Visual Basic, Version 6.0 Professional Edition, while development of the FORTRAN DLL is now being carried out using Compaq Visual Fortran Professional Edition, Version 6.1A.

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2-1

SECTION 2.0

INSTALLATION INSTRUCTIONS

The Windows version of FATEPEN/CVAT comes on multiple high-density, 3½-inch,

1.44 Mb diskettes or on a single CD. The installation files contained on the diskettes are compressed and, as such, should not be copied directly to your hard drive. The installation files on the CD are not compressed so they may be copied to your hard drive for installation directly off the hard drive. However, there is no real benefit installing from your hard drive versus installing FATEPEN from the CD.

The proper procedure to install FATEPEN for Windows is to place diskette #1 into your 3½-inch, high density drive, or the CD into your CD-Rom drive, and to run SETUP.EXE. After responding to a few prompts, SETUP will install FATEPEN/CVAT. The installation program loads the user interface (FPWIN.EXE) into the user-indicated subdirectory and the DLL containing the penetration algorithms (FATEPEN.DLL) into the \Windows\System subdirectory.

As FATEPEN/CVAT is a 32-bit code, it will neither install, nor run, on Windows 3.XX or below. FATEPEN/CVAT will only install and operate in Windows 95 or above.

Note: To insure proper installation of FATEPEN/CVAT it is recommended that you delete the old version of FPWIN.EXE from the proper destination directory prior to running the setup program

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SECTION 3.0

USER INSTRUCTIONS

This section of the report describes the activation of the program and the various options available to the user. Where appropriate, sample screens or screen portions will be shown.

The actual appearance of the screen on the installed system may vary slightly as a function of the video board manufacturer and fonts chosen by the user as the default Windows font.

Every effort has been made to develop each screen using standard default Windows fonts.

Unless otherwise stated, the terms FATEPEN and FATEPEN/CVAT are synonymous.

3.1 STARTING FATEPEN/CVAT

After installing the program onto your system, the easiest way to start FATEPEN/CVAT is to open the START menu, followed, in turn, by PROGRAMS, FATEPEN, and FPWIN. If it is anticipated that FATEPEN/CVAT will get a lot of use, it is recommended that the user create a SHORTCUT to run FATEPEN/CVAT. The user is referred to the Windows On-line Help topic entitled SHORTCUTS for assistance, if needed.

Once activated, FATEPEN/CVAT displays an opening form containing information on software revision, primary sponsorship, developer, distribution and control, and copyright notices. An example of the opening screen is shown below.

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The opening screen remains visible until the user positions their mouse cursor anywhere within the boarder of the center form and single clicks, or until 20-seconds have elapsed from the start of the program. This screen can be redisplayed by the user at any time.

Refer to Section 3.8.1.

3.2 OVERVIEW OF PRIMARY SCREEN OPTIONS

The primary screen provides the user with access to all of FATEPEN/CVAT’s controls. The earlier release of FATEPEN provided the user with access to all options through drop-down menu items found at the top of the screen. This release provides quicker access to FATEPEN’s options through command buttons. Command buttons not only provide quicker access to FATEPEN functions, but also let the user know at a glance what functions are available. The original menu structure has been maintained so as to ease the transition from menus to command buttons for previous FATEPEN users. Other than this overview section, this manual will only discuss the use of the command buttons. All command button functions are duplicated in the drop-down menu options.

Each of the primary menu options can be expanded by a single click of the left mouse button (referred to simply as a single click) on the option name. Note: two rapid-sequential single clicks are referred to as a double click. An example of the primary screen is shown below. Each option is described in detail in subsequent sections.

The command buttons within the File Commands frame, and the options under the File menu, are used to access the input/output options such as reading parameter files, writing parameter files, saving results to files, and printing results. The File menu option also includes the command to exit the FATEPEN/CVAT program. The Exit option is a separate command button located outside of the File Commands box.

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The command buttons within the Edit Parameters frame, and the options under the Edit menu, provide access to the editing options for the penetrator, target, and list parameters.

The command buttons within the View Parameters and Results frame, and the options under the View menu, allow the user to examine their input parameters as well as the output data generated by FATEPEN/CVAT.

The command buttons within the Discard Results frame, and the options under the Discard menu, give the user a quick way to delete output results without having to view the data.

The Run command button and Run menu option is used when the user wishes to run the FATEPEN penetration routines. It gives the user various iteration options.

The Help option provides the user access to the opening information form mentioned in Section 3.1. There is no equivalent command button for this options.

3.3 FILE COMMANDS

The File Commands frame contains command buttons which provide the user access to options for saving and loading of parameter files, and saving and printing output results. A single click on the appropriate command button activates the desired option. Each option is described in more detail in the sections that follow.

3.3.1 Load Parameters

The Load Parameters option opens another form which is used to retrieve previously stored parameter files from disk. This form is shown below.

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An examination of the Parameter Load form shows that there are three distinct areas on the form, each associated with a different type of parameter. The left most third of the form, enclosed by its own frame, is entitled “Penetrator Parameters”. The middle third of the form, enclosed by its own frame, is entitled “Target Parameters”. The right-most third of the form, enclosed by its own frame, is entitled “List Parameters”. Each frame is used to control the retrieval of its associated type of parameter file, i.e., penetrator, target, and list parameters, respectively. All three sections have similar layouts, with the exception that the Penetrator Parameter section has some additional objects.

It is easiest to describe the functionality of this form by beginning with the Drive box in the Penetrator Parameter frame. This object, as the name suggests, controls which drive letter is being looked toward for parameter files. To change to a different drive, single click on the Drive box. The Drive box will expand downward to reveal a list of the available drive letters.

A single click on any of the drive letters listed will cause the program to look toward the newly indicated drive for parameter files.

The next object used in selecting parameter files involves the Directory box located below the Drive box of the Penetrator Parameter frame. The Directory box controls which subdirectory or folder on the current drive is being examined for parameter files. (For purposes of this report, the terms subdirectory and folder are synonymous). The current folder is indicated by the open-folder symbol next to the name of the folder. Furthermore, subfolders (folders within folders) are indicated by being slightly indented with respect to the folder which they are within.

To maneuver through the labyrinth of folders and subfolders, double click on the folder name or symbol. This will place you within the selected folder.

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Once the desired Drive and Directory have been reached, the File List box within each parameter frame will contain the names of the available parameter files which end with the appropriate file name extension. By default, penetrator parameter file names end with the file name extension “.PEN”, target parameter file names use “.PLT”, and list parameter files end with “.LST”.

If it is necessary to view file names with extensions other than the default extensions, the Search Pattern box provides an option to view all of the available files. Single click on the Search Pattern box and select the “All Files” option.

When the desired parameter files are visible within the File List boxes, double click on the parameter file names to place the names of the files in the File Name boxes. Optionally, you may type the names of the files directly into the File Name boxes.

As FATEPEN can hold parameters for five penetrators in memory at the same time, when loading a penetrator file you must also select, with a single click, which of the five possible penetrator numbers you wish to load to. If a penetrator number is not selected, the penetrator file will not be loaded.

Note that it is not necessary to select file names for all three parameter types. Only select file names for parameters you wish to load. If you type or select a file name and then change your mind about loading it, you may use the Clear button in the upper right corner of each frame to erase the file name from the File name box.

The previous explanation of how to load parameter files assumed that all of the parameter file types which were desired were located within the same folder. As a convenience to the user FATEPEN’s Parameter Load form assumes this is the case by default. However, this may not always be true. When different parameter file type are located in different folders, single click on the Option menu command. This drops a single menu option called Synchronize Directories. The relevant portion of the screen which shows this menu option is shown below.

Notice that in this example, there is a check-mark next to the menu option. This means that all three parameter file type frames will look to the drive and directory selected in the penetrator parameter frame.

To turn this option off, single click on the Synchronize Directories menu option. The Parameter Load form will change, as shown below. Each Parameter type frame now contains it’s own Drive and Directory boxes, thus allowing each parameter type to be sought in independent locations.

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Once the desired file name(s) have been selected, either single click on the Accept menu option to load the parameters into memory, or single click on the Cancel menu option to cancel the operation without loading any parameters.

It is possible that a penetrator file may contain values for all five penetrators rather than just a single penetrator (see Section 3.3.2 - Save Parameters for more details on how to do this). If this is the case, a message will appear on the screen to let you know that the file you are about to load contains multiple penetrators. Your options are to proceed and load all five penetrator parameters and overwrite the current parameters, or to cancel the parameter load.

3.3.2 Save Parameters

The Save Parameters option opens another form which is used to save penetrator, target, and/or list parameters to disk. The form is shown below.

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An examination of the Parameter Save form shows that there are three distinct areas on the form, each associated with a different type of parameter. The left most third of the form, enclosed by its own frame, is entitled “Penetrator Parameters”. The middle third of the form, enclosed by its own frame, is entitled “Target Parameters”. The right-most third of the form, enclosed by its own frame, is entitled “List Parameters”. Each frame is used to control the saving of its associated type of parameter file, i.e., penetrator, target, and list parameters, respectively. All three sections have similar layouts, with the exception that the Penetrator Parameter section has some additional objects.

It is easiest to describe the functionality of this form by beginning with the Drive box in the Penetrator Parameter frame. This object, as the name suggests, controls which drive letter is being looked toward to save parameter files. To change to a different drive, single click on the Drive box. The Drive box will expand downward to reveal a list of the available drive letters. A single click on any of the drive letters listed will cause the program to look toward the newly indicated drive to save parameter files.

The next object used in saving parameter files involves the Directory box located below the Drive box of the Penetrator Parameter frame. The Directory box controls which subdirectory or folder on the current drive is being considered to save parameter files. (For purposes of this report, the terms subdirectory and folder are synonymous). The current folder is indicated by the open-folder symbol next to the name of the folder. Furthermore, subfolders (folders within folders) are indicated by being slightly indented with respect to the folder which they are within.

To maneuver through the labyrinth of folders and subfolders, double click on the folder name or symbol. This will place you within the selected folder.

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Once the desired Drive and Directory have been reached, the File List box within each parameter frame will contain the names of the current parameter files which end with the appropriate file name extension. By default, penetrator parameter file names end with the file name extension “.PEN”, target parameter file names use “.PLT”, and list parameter files end with “.LST”.

If it is necessary to view file names with extensions other than the default extensions, the Search Pattern box provides an option to view all of the available files. Single click on the Search Pattern box and select the “All Files” option.

At this point, you may type the names of the files under which you want to save the current parameters. It is recommended, but not mandatory, that you do not add a file name extension, that you let FATEPEN use the default extensions. If you wish to write over existing files, you may either type the names of the files directly, or double click on the file names. If any of the File Name boxes are left blank, the data for that particular parameter type will not be saved at this time.

When saving penetrator parameters to a file, you must also select, with a single click, which of the five possible penetrator numbers you wish to save. A 6th save option allows you to save all five penetrators to the same file. If a penetrator number is not selected, the penetrator file will not be saved at this time.

Note again, that it is not necessary to provide file names for all three parameter types. Only select file names for parameters you wish to save. If you type or select a file name and then change your mind about saving it, you may use the Clear button in the upper right corner of each frame to erase the file name from the File name box.

The previous explanation of how to save parameter files assumed that it was desired to place all of the parameter file types within the same folder. As a convenience to the user, FATEPEN’s Parameter Save form assumes this is the case by default. However, we know that this may not always be true. When you wish to save different parameter file types to different folders, single click on the Option menu command. This drops a single menu option called Synchronize Directories. The relevant portion of the screen which shows this menu option is shown below.

Notice that in this example, there is a check-mark next to the menu option. This means that all three parameter file type frames will look to the drive and directory selected in the penetrator parameter frame.

To turn this option off, single click on the Synchronize Directories menu option. The Parameter Save form will change, as shown below. Each Parameter type frame now contains it’s own Drive and Directory boxes, thus allowing each parameter type to be saved to independent locations. Once the desired file name(s) have been selected, either single

3-9 click on the Accept menu option to save the parameters to the indicated locations, or single click on the Cancel menu option to cancel the operation without saving the parameters.

3.3.3 Save Results

The Save Results frame contains three options. FATEPEN can produce from one to three different output results, depending on which options are selected. The standard output is referred to as the “Damage Results”. The first optional output is referred to as the “List Parameter Results”, while the second optional output refers to component vulnerability, or “CV Results”. Each of these output results are covered in greater detail later in this report.

As the partial screen sample below shows, the three additional options under the Save Results option correspond to the three different types of available results.

It should be noted here that these options will only be available if the user has run the penetration model (see Section 3.7) and produced the relevant output results, i.e., if no output has been produced of a particular type, the corresponding command button will appear in gray letters, rather than black letters, and cannot be accessed.

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3.3.3.1 Damage Results

Choosing the command button to save damage results produces a standard Windows dialog box which allows the user to specify the name and location of the damage file to be saved. The standard form is shown below.

It is important to note is that the default “type” for a damage file is actually a standard ASCII file with a default file name extension of “.DAM”. The damage file name may be either typed into the box entitled File Name, or the user may double-click on an existing file name.

Once a file name has been entered, the user must press the Save button to proceed. The user may optionally press the Cancel button to terminate the save option.

If the contents of the File Name box matches an existing file name, the user will receive a prompt advising them that they are about to write over an existing file. They are given the option to proceed or not.

The default file name extension is assigned if the user does not supply one. It is also possible to switch drives and folders from within this dialog box as well as create new folders. Refer to your Windows documentation for help in these areas.

Once the damage results have been saved, any menus which refer to Damage Results will appear in gray letters, meaning they are not accessible.

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3.3.3.2 List Parameter Results

Choosing the command button to save list parameter results produces a standard Windows dialog box which allows the user to specify the name and location of the list file to be saved.

The standard form is shown below.

It is important to note is that the default “type” for a list parameter file is actually a standard ASCII file with a default file name extension of “.LIS”. The list parameter file name may be either typed into the box entitled File Name or the user may double-click on an existing file name. Once a file name has been entered, the user must press the Save button to proceed. The user may optionally press the Cancel button to terminate the save option.

If the contents of the File Name box matches an existing file name, the user will receive a prompt advising them that they are about to write over an existing file. They are given the option to proceed or not.

The default file name extension is assigned if the user does not supply one. It is also possible to switch drives and folders from within this dialog box as well as create new folders. Refer to your Windows documentation for help in these areas.

Once the list parameter results have been saved, any menus which refer to List Parameter Results will appear in gray letters, meaning they are not accessible.

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3.3.3.3 CV Results (Component Vulnerability Results)

Choosing the command button to save Component Vulnerability results produces a prompt for the user to select the format of the resulting file. The two formatting options include saving the data in a tabularized layout which is suitable for use in a report, or a “comma separated value” (CSV) layout which can be readily imported into any spreadsheet program. Refer to your spreadsheet program documentation for more information on the CSV file format. The prompt is shown below.

Once the output format has been specified, a standard Windows dialog box appears which allows the user to specify the name and location of the CV file to be saved. The standard form is shown below.

It is important to note is that the default “type” for a CV file is actually a standard ASCII file with a default file name extension of “.CVT”. The CV file name may be either typed into the box entitled File Name or the user may double-click on an existing file name. Once a file name has been entered, the user must press the Save button to proceed. The user may optionally press the Cancel button to terminate the save option.

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If the contents of the File Name box matches an existing file name, the user will receive a prompt advising them that they are about to write over an existing file. They are given the option to proceed or not.

The default file name extension is assigned if the user does not supply one. It is also possible to switch drives and folders from within this dialog box as well as create new folders. Refer to your Windows documentation for help in these areas.

Once the CV results have been saved, any menus which refer to CV Results will appear in gray letters, meaning they are not accessible.

3.3.4 Print Results

The Print Results frame contains three options. FATEPEN can produce from one to three different output results, depending on which options are selected. The standard output is referred to as the “Damage Results”. The first optional output is referred to as the “List Parameter Results”, while the second optional output refers to component vulnerability, or “CV Results”. Each of these output results are covered in great detail later in this report.

As the partial screen sample below shows, the three additional options under the Print Results option correspond to the three different types of available results.

It should be noted here that these options will only be available if the user has run the penetration model (see Section 3.7) and produced the relevant output results, i.e., if no output has been produced of a particular type, the corresponding command button will appear in gray letters, rather than black letters, and cannot be accessed.

Choosing any of the available options to print output results produces a standard Windows print-dialog box. The print-dialog box allows the user to select a printer and the number of copies of the output results to be printed. The standard form is shown below.

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Pressing the Cancel button terminates the print option. Pressing the OK button causes the associated output results to be printed.

3.4 EDIT OPTIONS

The Edit frame provides access to options for editing penetrator, target, and list parameters.

Each option is described in more detail in the sections that follow.

3.4.1 Penetrator Parameters

FATEPEN comes with five pre-defined penetrators. All five penetrators are 4140 steel cubes with a 294 Brinell hardness. The mass of the five cubes are 15, 30, 60, 120, and 240 grains. Other penetrator shapes, sizes, materials, and orientations can be defined by editing the default penetrator specifications and saving the changes as described below.

When the user first enters the penetrator editing screen, the 15 grain cube is selected for editing by default. The editing screen looks like the sample shown below.

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Penetrator Number. The first box, labeled “Penetrator Number”, is a drop-down control which provides access to each of the available penetrators. The “cursor” is currently positioned on this box, indicated by the shaded background within the box. A single click on the box causes the box to expand downward allowing the user to select a different penetrator number. This is shown in the partial screen sample below.

A single click on any of the available penetrator numbers will select the corresponding penetrator. The display will update to show all of the parameters for the selected penetrator. For example, to switch from the initial 15-grain steel cube to the 120-grain steel cube, select penetrator number 4. As the sample screen below shows, the display has been updated to reflect the newly chosen penetrator.

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The updated values include the weight, dimensions, and presented area of the selected penetrator. These properties are discussed in subsequent sections. Also note that the cursor position has moved from the penetrator number box to the material box.

Material. FATEPEN has seven penetrator materials in it’s current library. A single click on the material box causes the box to expand downward revealing the material names. This is shown in the partial screen display below.

A single click on any of the material names shown changes the current penetrator material.

When the penetrator material is changed, the display is updated to reflect the change.

Specifically, the contents of the alloy box will reflect the selected material, and the contents of the Density Ratio box will be updated to reflect the change in density of the selected material. Both of these properties are covered in subsequent sections.

The partial screen display below shows the results of changing from a steel alloy material to a tungsten alloy.

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It can be seen that the contents of the alloy box has changed. It now contains a proper alloy designation for tungsten whereas before it contained a steel alloy designation.

Furthermore, since no other parameters have changed, i.e., dimensions and weight, the box labeled “Density Ratio” has changed value and color to reflect the fact that the dimensions, density, and weight are not consistent with a homogeneous material. If everything were consistent, the density ratio box would contain the value 1 and would be colored white. Refer to the section below entitled “Compute” for more information on density ratio.

A second example, shown in the following partial screen display, represents a further change of material to depleted uranium.

Notice that the alloy box is blank and that the label “Alloy” is grayed out. This means that there are currently no alloy designations available for the selected material. Also, the cursor is currently sitting on the weight box. It can also be seen that the value contained within the density ratio box is slightly different than it was in the previous example. This reflects the difference in density between tungsten and depleted uranium.

Weight. The weight box allows the user to enter penetrator weight in grains. Upon entering a carriage return, or using the mouse to place the cursor on a different object, the value displayed in the density ratio box changes accordingly. If a carriage return is entered, the cursor moves to the hardness box. Refer to the section below entitled “Compute” for more information on density ratio.

Hardness. The hardness box allows the user to enter penetrator hardness using the Brinell hardness scale. Table 3-1 shows typical reference hardness values for the different penetrator materials in FATEPEN.

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Table 3-1. FATEPEN Penetrator Materials and Typical Brinell Hardness Values

Penetrator Material

FATEPEN

Abbreviatio n

Brinell Hardness

Steel - RHA (mil-s 12560) ST 300 - 350 Steel - Mild Structured ST 150 Steel - Ship Armor ST 200 - 250 Steel - High Hard (mils-s 46-1008) ST 485 - 530 Tungsten - GTE WN WN007FU WF 285 Tungsten - WHA 1597 008FE WF 264 Tungsten - WHA 1598 009CO WF 280 Tantalum - NRC 76 TA w/ 2.5%W TA 255 Tantalum - Pure TA 170 Depleted Uranium - MSC DU-Ti DU 421 Depleted Uranium - Pure DU 231 Aluminum - 2024-T3 AL 120 Aluminum - 5083-H113 AL 82 Aluminum - 6061-T6 AL 95 Aluminum - 7075-T6 AL 150 Titanium - 6Al-4V TI 285 Aluminum/Teflon AT 6*

*Note: Aluminum/Teflon Brinell Hardness of 6 reflects Ultimate Strength of 3000 psi.

Shape Parameters. FATEPEN allows the penetrator to assume one of five basic shapes, a parallelepiped, a cylinder, a sphere, an armor piercing projectile, and a tapered / truncated right circular cylinder. These basic shapes are illustrated in Figure 3-1 below.

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Figure 3-1. Basic FATEPEN Penetrator Shapes and Orientation Angles

The shape parameter options are all contained within a framed area of the penetrator editing form. The portion of the form that deals with shape is shown below.

Shape parameters include the actual shape designation as well as the dimensions associated with the selected shape. In the partial screen sample above, the current penetrator is designated as a parallelepiped. Furthermore, the user has indicated that it is a cube. The option to designate a parallelepiped as a cube is a convenience feature for the user. By checking the cube box, FATEPEN automatically sets the remaining dimensions of the parallelepiped based on the value of the Thickness dimension. Notice that the thickness dimension is displayed with black characters, while the width and length dimensions are displayed with gray characters, (indicating that they are inaccessible). If the user wishes to specify the individual dimensions of the parallelepiped, click on the cube box to uncheck it. All three dimension boxes become available to the user for input, as shown below.

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The cylinder shape option offers the user two nose-shape options, a flat-ended cylinder or a round-nosed cylinder. The round nose cylinder is a flat-ended cylinder with the end capped by a hemisphere. Figure 3-2 below illustrates these two nose shapes.

Figure 3-2. Flat-Nosed and Round-Nosed Cylindrical Penetrators

The flat-nosed cylinder is 0.1964-inch long. It is necessary to increase the length of the round-nosed cylinder if the original mass is to be maintained. In the partial screen sample below, the length of the cylinder is properly increased when the round nose shape is selected. L/D does not change as it refers to the equivalent cylinder which is always flat-ended.

Other available shapes include a tapered / truncated right circular cylinder, a sphere, and a catalog of armor-piercing projectiles. As each shape is selected, the titles and number of dimensions changes accordingly. For example, in the case of a cylinder, there are only two dimensions needed. A sphere only needs a single dimension. These two selections are shown in the two partial screen samples below.

A tapered / truncated cylinder requires 4 dimensions to fully describe it. An armor piercing projectile, which is a special case of a tapered / truncated cylinder, does not require any

3-21 user input as the dimensions are defined when the user makes a selection from the catalog of available AP’s. Samples of these screens are shown below.

In addition to the penetrator shape designation and its associated dimensions, the display includes additional information. In the case of a parallelepiped, the user is provided with aspect ratio information, L/W (length/width) and T/W (thickness/width).

An equivalent right circular cylinder is defined for each penetrator for use in the terminal ballistic routines in computing penetrator presented areas and changes in orientation between impacts. The equivalent cylinder dimensions (D and L/D) are displayed below the actual dimensions and is determined as follows.

The diameter of the equivalent cylinder of a parallelepiped preserves the end-on presented area while the length of the equivalent cylinder is the same as the length of the parallelepiped.

In the case of a right-circular cylinder, the dimensions of the equivalent cylinder are the same as the original cylinder. For a sphere, the equivalent cylinder is determined as an L/D = 1 cylinder which preserves the mass of the sphere.

When a tapered /…