J3_2018_Vehicle_Measurement_Techniques.pdf

C6 C5 C4 C3 C2 C1

NHTSA

Field Crash Investigations

1/2018 Edition

Vehicle Measurement Techniques

U.S. Department of Transportation National Highway Traffic Safety Administration National Center for Statistics and Analysis Washington, DC 20590

NHTSA Field Crash Investigations

For NHTSA Field Crash Investigation use only – distribution not authorized.

TABLE OF CONTENTS

1.0 INTRODUCTION

2.0 POINT-TO-POINT MEASURING TECHNIQUE

FIGURE 1: FREESPACE

FIGURE 2: BUMPER LEAD, TAPER, and ABOVE BUMPER

FREESPACE

2.1 Defining Bumper Corner …………………………………………………………………3

FIGURE 3: LOCATING BUMPER CORNER…………………………………3

3.0 INPUT FOR THE RECONSTRUCTION PROGRAMS: L, C, and D DIMENSIONS ... 4

3.1 The L Dimensions

FIGURE 4: L DIMENSIONS

3.2 The C Dimensions

FIGURE 5: FRONT C DIMENSIONS

FIGURE 6: SIDE C DIMENSIONS

3.3 The D Dimension

FIGURE 7: D DIMENSIONS

4.0 DOCUMENTATION OF VEHICLE END PLANE IMPACTS (FRONT OR REAR)

4.1 Placement of Total Station

FIGURE 8: Total Station

4.2 Documentation of the Damaged End Plane Crush

FIGURE 9: DAMAGE PROFILE WITHIN OVERALL LENGTH

FIGURE 10: DAMAGE PROFILE BEYOND OVERALL LENGTH

4.3 End Plane Impacts: Exceptions to Standard Measurement Protocol

4.3.1 Crush Averaging for Underride Impacts

4.3.2 EAD Movement

4.3.3 Vertical Bumper Rotation

FIGURE 11: BUMPER ROTATION

4.3.4 Fiberglass or Non-steel Bodied Vehicles

United States Department of Transportation National Highway Traffic Safety Administration National Center for Statistics and Analysis Washington, DC 20590

5.0 DOCUMENTATION OF VEHICLE SIDE IMPACTS

5.1 Documentation of the Vehicle Side Plane Crush Profile

5.1.1 Identify the Field L

FIGURE 12: DEFLECTION POINTS

FIGURE 13: DEFLECTION POINTS

FIGURE 14: DEFLECTION POINT TO CORNER

5.1.2 Documentation of the Damage Profile

FIGURE 15: SIDE CRUSH DOCUMENTATION

FIGURE 16: SIDE CRUSH DOCUMENTATION BOWED VEHICLE ... 17

5.3 Side Plane Impacts: Exceptions to Standard Measurement Protocol

5.3.1 Crush Averaging for Underride Damage

5.3.2 Fiberglass or Non-steel Bodied Vehicles

5.3.3 Side Impact Resulting in Pocketing Damage

FIGURE 17: POCKETING DAMAGE

5.4 Documentation of Pillar Damage, Sill Height, DSD, and Crush Height

5.4.1 Direct Damage to Pillars

FIGURE 18: DIRECT DAMAGE TO PILLARS

5.4.2 Vertical Height of Sill

FIGURE 19: HEIGHT OF SILL

5.4.3 Door Sill Differential (DSD)

FIGURE 20: DOOR SILL DIFFERENTIAL

5.4.4 Height of Max Crush

FIGURE 21: HEIGHT OF MAX CRUSH

6.0 Documentation of Vehicle Rollover

6.1 Side Plane

6.1.1 Side Plane Zones

FIGURE 22: SIDE PLANE ZONES

6.1.2 Side Plane Rollover Measurement

FIGURE 23: ROLLOVER SIDE MEASUREMENTS

6.2 Top Plane

6.2.1 Top Plane Zones

FIGURE 24: TOP PLANE ZONES

6.2.2 Top Plane Measurement

FIGURE 25: ROLLOVER TOP MEASUREMENTS …………………….24

APPENDIX A

SEVERE UNDERRIDE DAMAGE

APPENDIX B

DOCUMENTING SHIFT/BOWING FOR CDC

APPENDIX C

DOCUMENTING DAMAGE WITHOUT TOTAL STATION

APPENDIX D

REQUIRED VEHICLE SKETCH MEASUREMENTS

VEHICLE MEASUREMENT TECHNIQUES

1.0 INTRODUCTION

This document was developed to provide a guideline for the collection of vehicle damage data coded in NHTSA Data Systems. This manual includes techniques for field vehicle damage data collection and instructions regarding the use of these measurements in the crash reconstruction program WinSMASH. The damage data described in this manual is used as an input to the damage algorithm of the WinSMASH program.

It is important that Technicians understand that they must provide data for the computer program in a format that will generate the most accurate results. Because there are a variety of crash types and configurations, the logic of the program must be considered when preparing the data for input.

The stiffness coefficients of the damage based algorithm of WinSMASH are derived from staged collision data. The algorithm assumes homogeneous stiffness across the front, side and rear structure of the vehicle; therefore, determining whether the collision damage occurred at a structurally strong or weak area of the vehicle is beyond the capability of the program. In WinSMASH, the derived stiffness coefficients for the front and rear end planes are representative of the stiffness of the most rigid structures of the vehicle, i.e. the bumper level.

Therefore, in the end impacts the bumper level must be given the primary emphasis when obtaining the measurement.

The WinSMASH side plane stiffness coefficients are derived from US Federal Motor Vehicle Safety Standard (FMVSS) 214 crash tests. In the side impact testing, the moving deformable barrier (MDB) directly engages the side sill (rocker panel) while impacting the passenger compartment door area at the door beam level. The side stiffness coefficients are derived from the measurements taken at the door beam level. As a result, in side plane impacts the best representation of the derived stiffness coefficients is roughly the mid door level, therefore, it must be given the primary emphasis when obtaining the measurement.

If the structure of the vehicle no longer reflects the stiffness coefficients due to significant deterioration or modification, the vehicle is not applicable to the program. When the most rigid structure (e.g., bumper/frame or side door beam) of the vehicle is not involved, such as in an extreme underride (see Appendix A), the stiffness coefficients are no longer valid and the reconstruction programs should not be utilized. Since only one vehicle damage data set can be entered for each impact, emphasis is placed on the damage level at which the stiffness coefficients were determined (i.e., frame or bumper level on end plane damage and door beam level on side plane damage). Using these procedures as the rule, certain other types of impacts, which violate the basic WinSMASH assumptions, have been accepted by making adjustments to the damage measurement values.

The basis for field data collection is the point-to-point vehicle measurement technique. The measurements are obtained by measuring the residual crush and subtracting the bumper/body taper to obtain the resultant crush profile.

2.0 POINT-TO-POINT MEASURING TECHNIQUE

Point-to-point measurement is defined as the actual distance a specific component moved within its damaged plane. Freespace is the area between the original (undamaged) surface of the vehicle and the reference line created by the maximum length and width of the vehicles body and/or bumper taper (See Figure 1). This freespace must be subtracted from the C measurements when measuring from the reference line to the damaged area. Similarly, when measuring above the bumper to points on the vehicle's front end (grille or front edge of the hood or fenders), the above bumper freespace must be subtracted to obtain actual crush (See Figure 2).

Freespace may be obtained from this vehicle, an exemplar vehicle, or the FARO model.

Above Bumper Freespace

FIGURE 1:

FREESPACE

FIGURE 2: BUMPER LEAD and TAPER, ABOVE BUMPER FREESPACE

Reference Line

Reference Line

Body Taper Freespace

Bumper Taper Freespace

Bumper Taper Freespace

Bumper Lead Freespace

Reference Line

Measured Crush

2.1 Defining Bumper Corner (Apex)

A bumper corner, sometimes referred to as an apex, is the location where vehicle end planes and side planes meet; it defines the front, back, left and right planes of the vehicle. The distance from one end plane bumper corner to the other is referred to as the Undeformed End Width (UEW). The contoured design of vehicles makes it necessary to project the geometrical corner to the surface of the vehicle.

It is important to determine bumper corner locations in an accurate and practical way during field inspections. The contoured design of some vehicles allows bumper corners to simply be identified visually. For vehicles where the corner is not apparent, use the following process to locate the bumper corner:

1. Extend the front and side planes in straight lines as illustrated by the dashed lines in Figure 3. To extend vehicle planes, create straight lines by using pocket rods, tape measures, or a combination.

2. At the point where the extended lines intersect, project a 45° line to the bumper surface as illustrated by the solid line.

3. The point at which the 45° projection meets the bumper surface is the location of the bumper corner.

4. If the bumper cover is off, the outermost point of the bumper support is the location of the bumper corner.

FIGURE 3: Locating Bumper Corner

RF

Bumper Corner

LF

Bumper Corner

3.0 INPUT FOR THE RECONSTRUCTION PROGRAM: L, C, and D DIMENSIONS

In order to describe the vehicle damage profile to the reconstruction program, the length (L), depth (Cs), and the location (D) of the damage must be documented. These dimensions are defined in the following paragraphs.

3.1 The Damage Length L Dimensions (Smash L)

The Damage Length is required as an input to WinSMASH program. It could be Field L or the Undeformed End Width (UEW). The Field L is the length of the direct and induced damage (restricted to the initial plane of contact, end or side) measured parallel to the lateral axis for end and longitudinal axis for side damage. The UEW is the distance on an undamaged end plane measured corner to corner. It is important to follow the same damage length measurement protocol that is used in the stiffness coefficient calculations for WinSMASH.

On end plane impacts where the Field L includes the entire width of the end plane (i.e., corner to corner), use the UEW for the damage length in WinSMASH. If the Field L does not extend across the entire end plane, then use the Field L for the damage length in WinSMASH. If the narrow object, such as a pole, is impacted by a vehicle and the vehicle wraps around the object such that total length of damage is less than the width of the object, use the UEW as the damage length in the Barrier option in the WinSMASH program.

On side plane impacts, enter the Field L for the Damage Length in WinSMASH. The length should include the entire direct and induced damage pattern, minus remote buckling.

UEW = SMASH L

FIGURE 4:

L DIMENSIONS

3.2 The C Dimensions

The C dimensions are crush depth measurements taken at specific points along the Field L to report the damage depth of the crush profile. The crush measurements are obtained every 10 cm along the Field L and must include the maximum crush. Once the crush measurements have been collected with the total station and downloaded into FARO, the software takes all of the measured crush points and converts them into six C measures for use in the WinSMASH program. See Figures 5 and 6.

Only one set of Cs can be entered into the program, although measurements at additional planes may be required for averaging. The crush profile entered must be the best representation of the structural damage to the vehicle. For additional information on obtaining C measurements, refer to the end and side plane damage documentation procedures discussed in Section 4.

3.3 The Damage Offset (D) Dimension

There are two measured “D” dimensions used in WinSMASH. They can be either positive or negative values. The Direct Damage D dimension (Direct +/- D) is the distance from the center of the direct damage width to the vehicle's damaged end plane center or the damaged wheelbase center. The center is represented by the CG symbol in Figure 7a, b, c. The Direct Damage length is measured along and parallel to the damaged plane (do not bend the tape measure).

The Field L D dimension (Field L +/- D) is the distance from the center of the Field L (direct and induced damage) to the vehicle’s damaged end plane center or the damaged wheelbase center, measured along the general slope of the damaged plane. On end impacts, use the vehicle’s damaged centerline (i.e., damaged or shifted center point on the end plane) to measure D. For side impacts, use the midpoint of the damaged wheelbase. The Direct +/- D is illustrated in Figure 7a, b, and c. The Field L +/- D is illustrated in figure 7a and is smaller than the Direct +/- D since the Field L extends further forward than the direct damage. In Figure 7b and c the Field L +/- D is zero, since the Field L goes across the entire front end, while the Direct +/- D is illustrated.

a b c

Direct center

Direct +/- D

FIGURE 7:

D DIMENSIONS

FLd

Center Damaged

Wheelbase

Field L

Field L +/- D

Direct +/- D

Direct +/- D

Field L center

4.0 DOCUMENTATION OF VEHICLE END PLANE IMPACTS (FRONT OR REAR)

4.1 Placement of Total Station

The total station is assembled and a new job is created using the protocols from the Total Station Setup Guidelines. The device should be placed in a location such that there is a clear point of sight to the crush that will be documented.

FIGURE 8:

Total Station

4.2 Documentation of the Damaged End Plane Crush Profile

For end plane impacts the Field L, length of the damaged area including direct and induced damage, does not extend laterally beyond the bumper corners. In other words, end plane crush should only be measured to vehicle components that were originally on the end plane of the vehicle. Once the total station has been set up, the crush profile should be documented using steps a-m below. If circumstances prohibit total station set up, refer to Appendix C.

a. On the end plane of a vehicle, the first measurement (C1) is defined as the left (driver’s perspective) end point of the damage. Place numbered (C1) orange visual marker at this point.

b. The last measurement (Cn) is defined as the right (driver’s perspective) end point of the damage. Place an orange visual marker at this point.

Note: In most cases end damage involves the entire plane; first measurement (C1) will be the left bumper corner and last measurement (Cn) will be the right bumper corner.

c. Measure the distance between the (C1 and Cn) parallel to the damaged plane using a tape measure and record the distance as the Field L. Do not bend the tape measure when obtaining the Field L measurement.

d. Place numbered orange visual markers along the Field L at 10cm increments.

e. The maximum crush (Cmax) point should be identified for photographic purposes by placing a single red visual marker above one of the orange C markers. Max crush should always be identified at one of the orange C markers. Minor adjustments to the orange C markers may be necessary to ensure max crush is captured.

f. Using a tape measure describe the location of the Field L and the Direct Damage with respect to the post-crash center point or bumper corner of the end plane. For example:

• Entire end plane

• Begins 4 centimeters right of center

• Begins at right front bumper corner and extends 50 cm to left

Measure the Direct Damage length along and parallel to the damaged plane (do not bend the tape measure). The Direct Damage should be identified for photographic purposes using green visual markers. Direct Damage does not have to located at one of the orange C markers, however, if it is in the same location place the green visual marker below the orange C marker.

g. Measure and document the value of the Direct +/- D and the Field L +/- D dimension using a tape measure as discussed in Section 3.3.

h. Identify any shifting of the frame rails and/or corners of the vehicle. See Appendix

B.

i. Assemble the total station using the Total Station Setup Guidelines.

j. Measure each of the crush points in order (from driver side to passenger side) using the total station. The measurements should always be taken at the structure (bumper) level and along the level of the most structural component when above bumper measurements are required (see 4.3.1 Crush Averaging).

k. Using the total station document the location of all the axles. Next, document the center of the rear plane for frontal impacts, or center of the front plane for rear impacts. The prism pole and reflector will be required to obtain the points. These points, which help identify the overall length, will be used to align the vehicle damage in FARO. In situations where after-market equipment has been added (i.e.

hitch, brush guard, or non-standard bumper) then the rear or front center point may need to be obtained from an alternate location. Examples include moving rear center point a few centimeters left or right or identifying the overall length using other components of the vehicle.

l. After the crush, axles, and centerline points have been obtained with the total station, import the file into the FARO software following the Total Station Download Protocols. The FARO software will generate six crush (C) values based on all the measured points. These six C measurements are then entered into the CISSWeb application.

m. Using the damaged vehicle, an exemplar vehicle, or the scaled FARO model of the vehicle, subtract the appropriate freespace from the crush at the approximate C positions to obtain the resultant crush. Multiple rows of freespace (i.e. bumper taper and EAD foam) may be needed. Use these freespace adjusted measurements for the final results. Use case notes if additional description of freespace location or measurements is necessary.

Figure 9 represents the end result of this procedure for vehicles with a damage profile within the confines of the original overall length. In Figure 10, the right bumper corner (C6) extends beyond the original overall length. The Field L includes both bumper corners and should not extend beyond those corners.

When the actual point on the vehicle has been moved outward, such as in an offset frontal impact where the non-contacted side of the bumper rotates outward beyond the original overall length, the measurement is negative since it moved out from its original position rather than crushed in. Since WinSMASH does not allow negative values for crush, zero is entered at these locations. In situations where the bumper was snagged and pulled outward during separation or during a subsequent impact, you would ignore that portion of the bumper affected by the snagging and measure to a representative crush plane either behind or above the bumper.

C1=CMAX C6 C6 C1

Field L Field L

C4 C5 C5 C2 C2 C3 C3 C4

CMAX

FIGURE 9: DAMAGE

PROFILE WITHIN

OVERALL LENGTH

FIGURE 10: DAMAGE

PROFILE BEYOND

OVERALL LENGTH

4.3 End Plane Impacts: Exceptions to Standard Measurement Protocol

4.3.1 Crush Averaging for Underride Impacts

An underride impact will result in uneven crush patterns between the bumper level and above bumper level. The following protocol is used when underride crush profiles are encountered. An adjustment to crush will be made only when there is above bumper crush that exceeds bumper level crush by 13 cm or more.

Take two sets of measurements of the end plane. Set up the total station and measure at both the bumper level and above bumper level. The above bumper measurements should be taken to the radiator or radiator support. If the grill and fender crush slopes rearward (i.e., it is not vertical), measure to the mid-line. As a rule, never measure to the hood edge, unless the hood is jammed shut and there is no other option. There will usually be a difference between the Field L measured at the bumper level and at the above bumper level. Enter the bumper level Field L when entering the measurements into the CISSWEB application.

Enter the crush measures generated by FARO along with the freespace for each level of measures into the CISSWEB application. If, after all freespace adjustments, the above bumper crush exceeds the bumper crush by 13 cm or more at any specific C location, the CISSWEB application will average the crush values at those C locations. Crush averaging is allowable at any number of C locations, provided the 13 cm or more variation exists. Note that the averaged value is used only for reconstruction programs. When the crush variation is less than 13 cm at a specific C location, use the bumper level crush for the reconstruction program. This applies even though the bumper level C measurement may equal zero.

4.3.2 Energy Absorbing Device Movement

When energy absorbing device (EAD) piston compression is the only damage to the vehicle, record the value but do not use it as a reconstruction program input or when averaging crush as described in Section 4.3.1. Use the bumper crush even if it is equal to zero.

When an EAD (such as a Styrofoam or plastic honeycomb insert) is undamaged and displaced in the crash, it needs to be accounted for in the crush measurements. If it cannot be reasonably put back into place, the thickness of the EAD (bumper lead) is measured and subtracted from the crush as a separate line of freespace – do not combine it with the contour freespace (bumper taper).

4.3.3 Vertical Bumper Rotation

If the bumper is rotated or twisted by the impact forces, an error in crush measurement of 3cm to 10cm can occur, depending on the degree of rotation and the size of the bumper. Crush measurements should be taken at the top or bottom of the bumper face whenever this situation exists with an adjustment row added to the crush profile. Figure 11 illustrates these situations.

4.3.4 Fiberglass or Non Steel Bodied Vehicles

The reconstruction program may be applicable to end plane impacts of non-steel bodied vehicles provided the maximum crush is at the bumper/frame area and an appropriate crush profile can be measured to a substantial structure. In most cases this may involve measuring to the steel reinforcement bar behind a plastic bumper. In this type of situation, free space will be significant and must be taken into account. If a representative crush profile cannot be obtained, measurements sufficient to encode a CDC (contact damage width and location, maximum crush) are required.

FIGURE 11: BUMPER ROTATION

5.0 DOCUMENTATION OF VEHICLE SIDE IMPACTS

5.1 Documentation of the Vehicle Side Plane Crush Profile

5.1.1 Identify the Field L

When measuring side damage, the length of the damaged area is the Field L. When the damage does not include the corner of the side plane of the vehicle, the Field L is identified by deflection points, which form a "yoke" in the vehicle profile (See Figure 12 and Figure 13). The yoke can generally be identified by sighting along the body side profile from each end of the vehicle and observing where the damage area departs from the original body contour. Note that this body contour may not be a straight line or plane. In addition, minor contact damage such as surface scratches outside of the deflection points are ignored when identifying the damage yoke, however, surface scratches from the same impact are included when determining the direct damage for CDC.

Figure 12: Deflection Points

Side damage profiles may extend to/from a corner to a deflection point. In this situation the Field L would be documented from the deflection point to the vehicle corner as illustrated in Figure 14. If the Field L does not include a corner and the crush measurements are taken near vertical mid door level the freespace will typically be zero. If the Field L includes a corner of the vehicle or if the crush measurements are taken at the sill or beltline levels then freespace should be collected.

Figure 13: Deflection Points

Figure 14: Deflection Point to Corner

5.1.2 Documenting the Side Damage Profile

The total station is assembled and a new job is created using the protocols from the Total Station Setup Guidelines. The device should be placed in a location such that there is clear point of sight to the crush that will be documented. Identify the Field L, then document the side damage using steps a-m below (see Figure 15). If circumstances prohibit total station set up, refer to Appendix C.

a. On side planes the first measurement (C1) is the rear most deflection point or damage end point. Locate C1 and place numbered orange visual marker at this point.

b. The last measurement (Cn) is the forward most deflection point or damage end point.

Locate Cn and place numbered orange visual marker at this point.

c. Measure the distance between C1 and Cn parallel to the damaged plane using a tape measure and record the distance as the Field L. Do not bend the tape measure when obtaining the Field L measurement.

d. The crush should be measured at the level best representing maximum crush, maintaining proximity to, or involvement of, structural components. Place numbered orange visual markers along the Field L at 10cm increments.

e. The maximum crush (Cmax) point should be identified for photographic purposes by placing a single red visual marker above one of the orange C markers. Max crush should always be identified at one of the orange C markers. Minor adjustments to the orange C markers may be necessary to ensure max crush is captured

f. Using a tape measure describe the location of the Field L and the Direct Damage with respect to an axle. For example:

• Begins 48 cm rearward of rear axle

• Damage begins 12 cm forward of front axle extending 143 cm rearward

Measure the Direct Damage length along and parallel to the damaged plane (do not bend the tape measure). The Direct Damage should be identified for photographic purposes using green visual markers. Direct Damage does not have to located at one of the orange C markers, however, if it is in the same location place the green visual marker below the orange C marker.

g. Measure and document the value of the Direct+/-D and Field L+/-D dimension using a tape measure as discussed in Section 3.3.

h. Identify any shifting/bowing of the vehicle. See Appendix B.

i. Assemble the total station using the Total Station Setup Guidelines.

j. Measure each of the crush points in order starting from the rear and moving forward using the total station. If there is hinge, latch, or pillar failure (complete separation), which allows the side surface to crush further, and there is a 13 cm or more difference between the sill level and the maximum crush level at any point, measure both levels of crush according to the protocol described in section 5.3.1.

k. Using the total station document the location of all the axles. Next, document the center of the front and rear plane. The prism pole and reflector will be required to obtain some of the points. These points will be used to align the vehicle damage in FARO. In situations where after-market equipment has been added (i.e. hitch, brush guard, or non-standard bumper) then the rear or front center point may need to be obtained from an alternate location. Examples include moving rear center point a few centimeters left or right or identifying the overall length using other components of the vehicle.

l. After the crush, axle, and centerline points have been obtained with the total station, import the file into the FARO software following the Total Station Download Protocols.

The FARO software will generate six crush (C) values based on all the measured points. These six C measurements are then entered into the CISSWeb application.

m. If the Field L includes a corner of the vehicle or if the crush measurements are taken at the sill or beltline levels then freespace should be collected. If the Field L does not include a corner and the crush measurements are taken near vertical mid door level the freespace will typically be zero. Using the damaged vehicle, an exemplar vehicle, or the scaled FARO model of the vehicle, subtract the appropriate freespace from the crush at the approximate C positions to obtain the resultant crush. Use these freespace adjusted measurements for the final results. Use case notes if additional description of freespace location or measurements is necessary.

The procedure for handling the severely bowed vehicle is the same as in Figure 15. This method automatically includes the bowing in the crush measurements. Figure 16 represents the end result of this procedure using steps a-m in Section 5.1.2 above.

FIGURE 16: SIDE

CRUSH

DOCUMENTATION

WITH

BOWING

FIGURE 15:

SIDE CRUSH

DOCUMENTATION

5.3 Side Plane Impacts: Exceptions to Standard Measurement Protocol

5.3.1 Crush Averaging for Underride Damage

An underride impact will result in uneven crush patterns between the sill and sheet metal panels above the sill. The following protocol is used when side underride crush profiles are encountered. An adjustment to crush will be made only when there is complete latch, pillar or hinge failure/separation, which allows the surface to crush further than normal.

When this occurs, measure the maximum crush level first, then measure the sill level.

Once the values are entered, the CISSWEB application will average any C location where there is a 13 cm or greater difference between the sill and maximum crush levels (even if the sill measurement equals zero). The maximum crush level will be used for the remaining C values.

5.3.2 Fiberglass or Non Steel Bodied Vehicles

Reconstruction programs may be applicable to side plane impacts of non-steel bodied vehicles provided the maximum crush is at the sill/frame area or the pillars and door beam area and an appropriate crush profile can be measured to a substantial structure. In most cases this may involve measuring to the steel reinforcement beam behind a plastic door or sill. In this type of situation, free space will be significant and must be taken into account.

5.3.3 Side Impact Resulting in Pocketing Damage

The Field L in Figure 17 is measured to the point of greatest pocketing. The C1 measurement is the perpendicular distance between the reference line and the point of greatest pocketing. The point of greatest pocketing is not necessarily the point of maximum lateral penetration.

FIGURE 17: POCKETING DAMAGE

5.4 Documentation of Side Impact Measurements

When a vehicle sustains left or right side damage that meets the side impact measurement criteria, the following protocols should be used to collect: Direct Damage to Pillars, Vertical Sill Height, Height of Door Max Crush, and the Door Sill Differential. These measurements are taken for the vehicle with side plane damage when all of the following conditions are met:

1. Vehicle to vehicle impact

2. Frontal plane to side plane impact

3. CDC column 4 equals D, P, Y, or Z

4. Max crush is to the P zone

5.4.1 Direct Damage to Pillars

All pillars that sustained direct damage from the striking vehicle are identified. In Figure 18, the B and C pillars would be positively indicated. The damage to the A pillar is induced damage rather than direct damage and would not be included.

5.4.2 Vertical Height of Sill

The vertical height of the sill is measured from the ground to the sill where it meets the door seam. This value is a precrash measurement and can be taken from the undamaged side of the inspected vehicle or an exemplary vehicle (Figure 19). If the tires on the vehicle are flat, the height of the flattened side wall should be added to the measurement. However, if the vehicle is modified (certified or not) exemplar vehicles or manufacturer specifications should not be used.

Sill height

FIGURE 18:

DIRECT DAMAGE

TO PILLARS

FIGURE 19:

EXEMPLARY

VEHICLE

HEIGHT

OF SILL

5.4.3 Door Sill Differential

The door sill differential is the post-crash lateral distance between the damaged sill and the maximum crush point at the door level. After the crush measurements have been taken and the maximum crush point has been determined, select the point on the sill that is aligned vertically with the location of max crush to determine the door sill differential (DSD). Frontal components on the vehicle in Figure 20 have been removed to provide a cut-away view of this measurement.

1. A pocket rod or tape measure is positioned vertically on the outside of the sill at a point aligned with the max crush of the door. This is a damaged measurement, so use the identified point whether or not there is damage to the sill at that location.

2. A second pocket rod is placed laterally at a right angle to the vertical rod.

3. The lateral rod is moved toward the vehicle until it makes contact at the point of max crush.

4. The measurement from the door surface to the vertical rod is recorded as the door sill differential.

5.4.4 Height of Maximum Crush

During the crush profile measurements, the point of max crush was located and recorded.

To obtain the height of max crush, a vertical measurement is taken from the max crush point to the ground (Figure 21). If the tires on the vehicle are flat, the height of the flattened side wall should be added to the measurement. However, if the vehicle is modified or damage prevents a reasonable estimate, do not use an exemplary or estimated measurement.

Door Sill Differential

FIGURE 20: DOOR

SILL DIFFERENTIAL

FIGURE 21:

HEIGHT OF

MAX CRUSH

6.0 Documentation of Vehicle Rollover Damage

Although crush gauge measurements are not required for rollovers, document the location of the primary direct damage area with respect to fixed points on the vehicle.

• Left roof rail to center of roof

• Right roof rail

Rollover documentation also measures the maximum crush at the greatest lateral and vertical locations to the greenhouse area of the vehicle. The max crush laterally and the max crush vertically may or may not occur to the same component. Documentation begins by identifying the points of max crush and establishing zones along the greenhouse of the damaged vehicle to best describe where the max crush occurred. Side plane zones are used to locate lateral crush, while top plane zones are used to locate vertical crush. See Figures 22 and 24.

6.1 Rollover Side Plane

6.1.1 Side Plane Zones

A-pillar Zone - Locate the top of the windshield frame and the center of the top of the B-pillar. Measure the distance and find the mid-point. From the foremost base of the A-pillar to the mid-point is the A-pillar Zone.

B-pillar Zone – Locate the center of the top of the B-pillar and the center of the top of the C-pillar. Measure the distance and find the mid-point. From the mid-point of the A and B pillars to the mid-point of the B and C pillars is the B-pillar Zone.

C-pillar Zone – Locate the center of the top of the C-pillar and the center of the top of the D-pillar. Measure the distance and find the mid-point. From the mid-point of the B and C pillars to the mid-point of the C and D pillars is the C-pillar area. If the C-pillar is the last of the pillars, the C-pillar Zone would end at the rearmost base of the C-pillar.

This same process is continued for each pillar present on the vehicle until the zones containing the max vertical and max lateral crush are identified.

Top of windshield frame

Top of B-pillar

Top of C-pillar

Top of D-pillar

Foremost base A-pillar

Mid-point Mid-point Mid-point

A-pillar Zone

D-pillar Zone

C-pillar Zone

B-pillar Zone

FIGURE 22:

ROLLOVER SIDE

PLANE ZONES

6.1.2 Side Plane Rollover Measurements

Side plane crush measurements are taken by sighting down the vehicle to locate an undeformed body line. A vertical rod is used to project the undeformed body line, while a lateral rod is extended to the maximum lateral crush as shown in Figure 23. The distance from the vertical rod to the surface of the vehicle is recorded. Using the undamaged side of the vehicle or an exemplary vehicle, place the vertical rod along the same undeformed body line. Extend a lateral rod to the same surface area of the vehicle used prior. The distance from the vertical rod to the surface of the vehicle is recorded. The difference of the two values is the resultant maximum lateral crush.

6.2 Rollover Top Plane

6.2.1 Top Plane Zones

Top plane zones are established by extending the side plane zones across the roof as illustrated in Figure 24. Only three zones are established for the top plane; the Windshield Header Zone, the Roof Zone, and the Back Light Header Zone. In this example with an SUV, the B-pillar and C-pillar zones used for the side plane have been combined for the top plane to form the Roof Zone.

Lateral crush value Lateral exemplary value

FIGURE 23: ROLLOVER

SIDE PLANE MEASUREMENTS

6.2.2 Top Plane Measurement

Top plane crush measurements are taken by sighting down the vehicle to locate an undeformed body line. A vertical rod is used to project the undeformed body line upward, and a lateral rod is placed at the point of maximum vertical crush. The distance from the vertical rod to the vertical max crush location is recorded. Using the undamaged side of the vehicle or an exemplary vehicle, place the vertical rod along the same undeformed body line. Extend a lateral rod to the previously documented point used on the damaged plane. The distance from the vertical rod to the surface of the vehicle is recorded. The difference of the two values is the resultant maximum vertical crush. See Figure 25.

Right Windshield Header Zone

Right Back Light Header Zone

Right Roof Zone

Left Roof Zone

Left Windshield Header Zone

Left Back Light Header Zone

Vertical crush value

Vertical exemplary value

FIGURE 25: ROLLOVER TOP PLANE MEASUREMENTS

FIGURE 24: ROLLOVER TOP PLANE ZONES

APPENDIX A

SEVERE UNDERRIDE DAMAGE

Not Applicable to Computer Reconstruction Program

Example A: Frontal impact - Damage is above the bumper/frame level. There is minimal engagement to the radiator and/or support components. Damage is generally restricted to the grille area, hood, and the top of the fenders.

Example B: An extension of Example A, damage continues into the greenhouse resulting in severe displacement of the hood, A pillars, windshield and header.

Example C: Frontal impact: Damage is restricted to the greenhouse area. There is no contact below the beltline.

Note: Similar damage profiles to those represented in Examples A, B, and C which occur to the rear plane are also severe underrides.

Example D: Due to the lack of mechanical parts, the area between the beltline and frame is significantly less rigid in rear impacts than in frontal impacts. Consequently, impacts which are above the bumper/frame area and which result in crush that extends beyond the rearmost pillar area are generally considered severe underrides and are excluded from the computer reconstruction program.

Example E: Side impacts, which are restricted to the area above the beltline, specifically the greenhouse, are considered severe underrides and are excluded from most reconstruction programs.

Example F: Side impact - While door guard beams provide structural rigidity, impacts which are restricted to the area above the sill/frame require caution with respect to the use of a reconstruction program. In Example F substantial greenhouse damage involves nearly one half of the passenger compartment. In most cases, this constitutes severe underride; however, some reconstruction programs may apply to less severe impacts above the sill/frame. Also, this would probably result in a latch, hinge or pillar failure, which would require using the averaging technique stated in section 5.3.1. to obtain a crush profile for use in the reconstruction program.

APPENDIX B

DOCUMENTING SHIFT/BOWING FOR CDC

LATERAL (HORIZONTAL) END SHIFT

For CDC incrementation purposes only, determine if the vehicle end structure (both frame rails or unibody) has shifted 10cm or more in the same direction. A technique for determining lateral (horizontal) end shift is to determine the undamaged centerline of the vehicle (best estimate usually made by aligning the inside rearview mirror with the center of the back light) and projecting the centerline to the end(s) of the vehicle. Refer to Figure 1b.

Measure the distance from the projected undamaged centerline to each frame rail end and compare this value to half the distance between the undamaged frame rails. A similar vehicle may have to be located to obtain this value. If an exemplar vehicle is not likely to be located, estimate the position of the undamaged frame end by projecting forward from the undamaged areas of the frame. Measure the half distance between the projected centerline and the projected undamaged frame end. If the measured value from the projected undamaged centerline differs from the half distance by 10cm or more for each frame rail end, check the appropriate box in the CISSWEB application to indicate shift. Another method for vehicles equipped with a frame is to estimate the position of undamaged frame ends by projecting forward from an undamaged portion of each frame member, then measure from this point to the damaged frame end to determine the amount of shift. Refer to Figure 2b.

For vehicles with unibodies, measure the distance from the undamaged centerline to the center of the shifted unibody end to determine the amount of end shift.

FIGURE 1b:

SHIFT TO CENTER

FIGURE 2b:

SHIFT TO RAILS

VERTICAL END SHIFT

Incrementing for vertical shift requires that only one frame rail (or portion of a unibody) shift vertically 10cm or more. If only one side (e.g., frame rail) of the end has shifted vertically, then you need only to compare it to the non-shifted side to determine if the shift is present. If the entire end has shifted vertically, then additional techniques may be required to accurately estimate the amount of shift. For example, measure vertically from the ground to the end of the frame/unibody and compare the measurement to that of an undamaged exemplar vehicle or to the, opposite, undamaged end of the vehicle. Keep in mind that the vehicle’s levelness will affect your measurements. If this procedure is not possible, estimate the position of the undamaged frame end by projecting forward from the undamaged areas of the frame. Measure from this estimated point to the damaged frame rail end (unibody) and annotate that the amount of shift is approximated. Figure 3b illustrates vertical end shift.

FIGURE 3b: VERTICAL END SHIFT

BOWING SHIFT

Bowing requires that, when struck in the side (usually between the axles) at least one end of the vehicle bows 10cm or more toward the impacted side. This is measured either at the original centerline of the vehicle or on the side opposite that which is impacted. When measuring at the centerline, use the inside rearview mirror/mount and the center of the back light to determine the original centerline. Project this out to the end plane, then measure from this projected point to the shifted center of the end plane (usually the center point of the bumper). If this measurement is 10cm or more at either end of the vehicle, check the appropriate shift box in the CISSWEB application. If you cannot locate the center(s) of the end plane(s), then run a reference line tangent to the undamaged side and parallel to the original centerline. Then measure from the reference line to the side of the bumper at the corner of the vehicle. If this measurement is 10cm or more at either end of the vehicle, check the appropriate shift direction in the CISSWEB application. Refer to Figure 4b.

FIGURE 4b: BOWING

APPENDIX C

DOCUMENTING CRUSH PROFILE WITHOUT TOTAL STATION

The total station should be used to document vehicle damage. In the rare circumstance where the use of the total station is not possible to document the vehicle damage profile, use the criteria below.

C.1 DOCUMENTATION OF VEHICLE END PLANE IMPACTS (FRONT OR REAR)

C.1.1 Establishment of a Reference Line for Crush Profile Measurements

The reference line used for vehicle end plane crush measurements is generally placed to represent the vehicle’s undamaged overall length.

1. Place two measurement stands on the undamaged end of the vehicle adjacent to each corner.

2. Extend a string line between the measurement stands such that the line is contacting only the furthermost longitudinal projection of the end plane. This point may be identified by the bumper peak at the centerline, or by original equipment bumper guards on the vehicle. Aftermarket bumper guards, spare tires, trailer hitches or similar add-on equipment should not be considered. Adjust the string line so it is at equal longitudinal distances (forward/rearward) from each bumper corner or from an undamaged component that can be identified on each side of the vehicle (e.g., side marker lights, axle center).

3. Using a tape measure, locate and record the reference line for the damaged end plane

(original undamaged position) by measuring parallel to each side of the vehicle from the previously positioned stands to a point equal to the overall length. While the tape measure is in place, it is advisable to obtain the wheelbase and overhang measurements. A plumb bob should be used to ensure accuracy. Figure 1c represents the end result of this procedure.

C.1.2 Documentation of the Damaged End Plane Crush Profile

For end plane impacts the Field L, length of the damaged area including direct and induced damage, does not extend laterally beyond the bumper corners. In other words, end plane crush should only be measured to vehicle components that were originally on the end plane of the vehicle. Once the reference line has been established as described in section C.1, the crush profile should be documented as follows:

a. On the end plane of a vehicle, C1 is defined as the left (driver’s perspective) end point of the damage. Place numbered (C1) orange visual marker at this point.

b. C6 is defined as the right (driver’s perspective) end point of the damage. Place numbered (C6) orange visual marker at this point.

Note: In most cases end damage involves the entire plane; C1 will be the left bumper corner and C6 will be the right bumper corner.

c. Measure the distance between the visual markers (C1 and C6) parallel to the reference line and record the distance as the Field L.

d. Divide the Field L by five to determine the spacing of the six C locations and place additional numbered orange visual markers at each of those points. Next, place tape on the reference line parallel to each of the six C locations.

FIGURE 1c: REFERENCE LINE

e. Measure the crush profile perpendicular to the visual markers at each C location and record these dimensions. The Cs should always be taken at the structure (bumper) level and along the level of the most structural component when above bumper measurements are required (see 4.3.1 Crush Averaging).

f. Measure and record the maximum crush (Cmax) point. This point should be highlighted with a red visual marker for photographic purposes. Cmax is recorded for determining the CDC extent zone. The point of the vehicle that is visually crushed the most may not be maximum crush once freespace is subtracted.

g. Using the damaged vehicle, an exemplar vehicle, or the scaled FARO model of the vehicle, subtract the appropriate freespace at each C position and the maximum crush position to obtain the correct crush. Use these freespace adjusted measurements for the final results and to assign max crush.

h. Locate and record an end of the Field L and the Direct Damage with respect to the post crash centerpoint or bumper corner of the end plane. For example:

• Entire end plane

• The left end begins 4 centimeters right of post crash center of the end plane

• Begins at right front bumper corner and extends 50 cm to left

The Direct Damage should be identified using green visual markers.

i. Measure and document the value of the Direct +/- D and the Field L +/- D dimension.

j. Measure/document shifting of the frame rails and/or corners of the vehicle. See

Appendix B.

C.2 DOCUMENTATION OF SIDE PLANE IMPACTS

C.2.1 Establishment of a Reference Line

There are two methods of reference line placement. They are: 1) the body contour reference line and 2) the measurement stand reference line. Vehicle bending (i.e., bowing) is not a consideration when selecting a reference line placement method.

The body contour reference line should be used whenever the string line can follow the body contour with little or no disruption (Figure 2c). The measurement stand reference line should be used whenever the impact involves a corner or damage alters the vehicle profile such that the first method cannot be used (Figure 3c). When uncertain which method to use, use the measurement stand reference line method.

Stringline is attached on body panel just above bumper corners

Protruding damage would cause over reporting of crush and prohibits using the body contour method

FIGURE 2c: ACCEPTABLE

REFERENCE LINE PLACEMENT

FIGURE 3c: UNACCEPTABLE

REFERENCE LINE PLACEMENT

C.2.2 Establishing the Body Contour Reference Line

The following protocol should be used whenever the damage (contact and induced), as defined by the deflection points, is inboard of both vehicle ends and nothing protrudes from the side of the vehicle that would deflect the reference line. This method does not require freespace adjustments to the crush measurements provided the measurements are taken near the mid-door vertical level which is the maximum width of the side body contour. If measurements are taken near the sill or near the beltline, then freespace adjustments must be made to compensate for the side body contour.

Attach a string line from the leading edge at the front body panel immediately above the bumper to the trailing edge of the rear body panel immediately above the bumper. Figure 4c represents the end result of this procedure.

String Line Attached

Deflection Point

Deflection Point

String Line Attached

FIGURE 4c:

BODY CONTOUR

REFERENCE LINE

C.2.3 Establishing the Measurement Stand Reference Line

In the majority of side impacts, the reference line will be attached directly to the vehicle. For those vehicles where this is not possible (e.g., sheet metal displacement or door protrusion alters the path of the reference line or crush extends to the corner of the vehicle) the reference line must be established using measurement stands. The basic principle of measurement stand placement is to establish a reference line at right angles from known points so actual crush can be determined.

In order to establish a reference line using the measurement stand method, it is essential to accurately locate the vehicle end plane centerpoint (Cp). The centerpoint is defined as the specific point on the end plane that defines the mid-point of that plane.

Example #1: Because the vehicle has protruding damage, the measurement stand reference line method is required. In order to establish a reference line that takes into account any bowing, each end of the reference line must be set out a constant distance from each endplane centerpoint. The minimum, and preferred, distance is one-half the overall width. If protrusions prohibit the reference line being established there, then each stand must be set out an additional distance until the protrusion is cleared.