MAESTRO Structural Loading and Response SOW.docx

Statement of Work Special Studies for MAESTRO Structural Loading and Response Implementation

CONTENTS

1 Introduction 2 Reference Materials 3 Scope of Work 4 Deliverables and Schedule 5 Quality Assurance 6 Security Clearance 7 Use of Government Furnished Equipment 8 Notes

1. INTRODUCTION

The USCG SFLC has been involved in a number of structural analysis efforts requiring risk based assessments to support engineering, operational and maintenance decisions. The structural analysis includes both ultimate hull girder strength and fatigue life evaluations. Variability of loading experienced on USCG Cutters is a specific example of factors affecting structural integrity requiring evaluation using a probabilistic risk based evaluation approach. The objective of this effort is to incorporate approaches for including non-linear hydrodynamic wave loading approaches to local and global structure response in the MAESTRO Wave and FEA modeling.

2.0 REFERENCE MATERIAL

The tasking described in this outline statement of work follows on to the tasking that has been performed by MAESTRO MARINE on this subject. Related reference material includes:

· MAESTRO Marine MAESTRO Wave analysis approach

· The interface code between the Rhinoceros 3D corrosion database tool and the MAESTRO code for ship structural design and analysis

3. SCOPE OF WORK

The following tasks shall be performed to achieve the objectives of the project:

Task 1 - 2D Slamming load calculation and calibration. The contractor shall validate MAESTRO’s 2D slamming implementations, Generalized Wagner Model (GWM) and Modified Logvinovich Model (MLM), for both head sea and oblique sea conditions. The validation will include running benchmark example case studies in three representative sea conditions chosen in coordination with the USCG. Case studies may include USCG vessels and data for use in validation efforts. Data analysis shall include comparison of pressure statistics (i.e. RMS, average of the one-tenth, and one-hundredth highest peak responses) for a structural panel.

Task 2 – Time domain-based fatigue analysis using hydroelastic model and modal superposition method. The contractor shall use the MAESTRO hydroelasticity module to investigate the global response of the ship structure due to slamming loads. The hydroelasticity approach is based on the modal superposition method and includes hydrodynamic wave loads and slamming loads. Data analysis will compare basic motion response, sectional load response, and fatigue damage estimates in three example seaways chosen in coordination with the USCG. The task will develop a Rainflow Counting method to extract the information of stress variations Δσ and cycles n from the time series. The fatigue damage will then be evaluated using Miner’s rule with and without hydroelastic response. The development process will be documented and several example cases will be analyzed and evaluated.

Task 3 – Time domain-based fatigue analysis using hydroelastic model and direct-integration method. While the modal superposition method is efficient for dynamic analysis, the direct-integration method is more flexible and accurate. The contractor shall develop a direct-integration method to solve the hydroelasticity model and then to calculate the basic motion statistical responses, sectional load responses, and structural fatigue life using the Rainflow Counting method with and without hydroelastic response in three example seaways chosen in coordination with the USCG. Test cases will be analyzed to evaluate the accuracy and effectiveness of the direct-integration procedure.

Task 4 – Technical Reviews and Reports The contractor shall prepare a letter report and MS Power Point brief on each of the tasks along with initial comparisons with model test and full scale response data provided by the USCG.

· Kick-off meeting with USCG SFLC

· Quarterly Technical Review Meetings with USCG SFLC

· Final Technical Review Meeting demonstrating functionality of features added

· Final Technical Report and Copies of developed software and data sets.

The contractor shall present the findings from the project to the USCG SFLC in Baltimore MD.

4. DELIVERABLES AND SCHEDULE

4.1 DELIVERABLES – The Contractor shall include in the report deliverables of Tasks 1 through 4 to SFLC-ESD-NAME-Nav Arch all photographs, illustrations, charts, graphs, tables, calculations, text, analyses, algorithms, conclusions and recommendations developed as a part of this project. After receiving SFLC-ESD-NAME-Nav Arch comments, the Contractor shall produce the updated deliverable within four weeks. Each deliverable, both draft and final, shall be transmitted to the SFLC-ESD-NAME-Nav Arch with a documenting cover letter and a copy of the cover letter shall be provided directly to the Contracting Officer.

4.2 Modifications to contractor submittals required by the government reviewers, if judged by the contractor to be outside the scope of this Statement of Work, shall be discussed at a meeting of the government technical and contracting personnel with contractor representatives.

4.3 SCHEDULE – The following schedule of events shall be followed by both the U.S. Coast Guard and the Contractor in carrying out the provisions of this Statement of Work. When either party becomes aware of their inability to conform to this schedule, they shall so advise the other party, in writing, propose an alternate schedule, and provide justification.

5. QUALITY ASSURANCE

5.1 The government reserves the right to witness the validation procedures and validation processes of any part of the project development at whatever site such action is taking place.

5.2 The government will review the contents and format of the deliverables in their entirety prior to issuing approval.

6. SECURITY CLEARANCE

6.1 This work is not classified. No security clearance is required.

7. USE OF GOVERNMENT FURNISHED MATERIAL

7.1 Government furnished material identified in this SOW shall be used for the delivery order only and shall not be used or disseminated for any other purpose.

8. NOTES

8.1 DELIVERY DESTINATION – All items to be delivered under this work statement shall be delivered to the SFLC ESD technical point of contact, Mr. Karl Stambaugh, with a documenting cover letter at the following address:

For each deliverable a copy of the cover letter shall be provided directly to the Contracting Officer at the following address:

707 E. Ordnance Rd Road, Suite 410 Baltimore, MD 21226-5000 Attn: XXXXXXX

8.2 RIGHTS IN DATA – All data produced exclusively and completely based on this effort, regardless of form or medium, are considered to be solely the property of the USCG and shall not be released without the written consent of the USCG.