1、_ SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising there
2、from, is the sole responsibility of the user.” SAE reviews each technical report at least every five years at which time it may be reaffirmed, revised, or cancelled. SAE invites your written comments and suggestions. Copyright 2007 SAE International All rights reserved. No part of this publication m
3、ay be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE. TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada) Tel: 724-776-4970 (outside USA)
4、 Fax: 724-776-0790 Email: CustomerServicesae.org SAE WEB ADDRESS: http:/www.sae.org J1733 REV. NOV2007 SURFACE VEHICLE INFORMATION REPORT Issued 1994-12 Revised 2007-11 Superseding J1733 DEC1994 (R) Sign Convention for Vehicle Crash Testing RATIONALE Revisions to SAE J1733 are a continuing process a
5、nd are considered at each five year review. Changes were made to include additional and new load cells and instrumentation along with procedures for determining their proper polarities. 1. SCOPE In order to compare test results obtained from different crash test facilities, standardized coordinate s
6、ystems need to be defined for crash test dummies, vehicle structures, and laboratory fixtures. In addition, recorded polarities for various transducer outputs need to be defined relative to positive directions of the appropriate coordinate systems. This SAE Information Report describes the standardi
7、zed sign convention and recorded output polarities for various transducers used in crash testing. 2. REFERENCES 2.1 Applicable Publications The following publications form a part of the specification to the extent specified herein. Unless otherwise indicated the latest revision of SAE publications s
8、hall apply. 2.1.1 SAE Publications Available from SAE, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada) or 724-776-4970 (outside USA), www.sae.org. SAE J211 Instrumentation for Impact Test SAE J670 Vehicle Dynamics Terminology SAE J1594 Vehicle Aerodynamic
9、s Terminology SAE J2052 Test Device Head Contact Duration Analysis Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Revised NOV2007 - 2 - 3. RIGHT-HANDED COORDINATE SYSTEM A right-handed coo
10、rdinate system consists of an ordered set of three mutually perpendicular axes (x, y, z) which have a common origin and whose positive directions point in the same directions as the ordered set of the thumb, forefinger, and middle finger of the right hand when positioned as shown in Figure 1. Note t
11、hat this configuration of x, y, and z axes always define a right-handed coordinate system independent of the orientation of the hand in space. To assure consistent vector directions of moments and angular velocities and accelerations calculated by vector multiplications all coordinate systems used i
12、n vehicle testing will be “right-handed“. Sections 4 and 5 will define standardized orientations of coordinate systems for the vehicle and dummy, respectively. Positive angular motion and moment directions are determined by the right-handed screw rule. If any of the three positive axes is grasped wi
13、th the right hand with the thumb extended in the positive direction, as shown in Figure 2 for the x-axis, then the curl of the fingers indicate the positive direction for angular motions and moments with respect to that axis. FIGURE 1 - THE CONFIGURATION OF A RIGHT-HANDED COORDINATE SYSTEM RELATIVE
14、TO THE THUMB, FOREFINGER, AND MIDDLE FINGER OF THE RIGHT HAND FIGURE 2 - RIGHT-HANDED SCREW RULE Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Revised NOV2007 - 3 - A simple method to det
15、ermine if a coordinate system is right-handed is to rotate the system 90 degrees about any of one of its positive axes using the right-handed screw rule. For a positive 90 degrees rotation about the +x-axis, the coordinate system is right-handed if the +y-axis rotates to the position previously occu
16、pied by the +z-axis. For a positive 90 degrees rotation about the +y-axis, the coordinate system is right-handed if the +z-axis rotates to the position previously occupied by the +x-axis. For a positive 90 degrees rotation about the +z-axis, the coordinate system is right-handed if the +x-axis rotat
17、es to the position previously occupied by the +y-axis. 4. VEHICLE COORDINATE SYSTEMS Vehicle coordinate systems will be consistent with the orientations specified in SAE J670 and SAE J1594. These orientations are shown in Figures 3 and 4, respectively. For structures within the vehicle that have a p
18、rinciple axis of motion such as the steering wheel column, the vehicle coordinate system may be rotated about the y-axis such that the +x-axis or +z-axis is directed along the column axis. FIGURE 3 - VEHICLE DYNAMICS COORDINATE SYSTEM - SAE J670 FIGURE 4 - VEHICLE AERODYNAMICS COORDINATE SYSTEM - SA
19、E J1594 Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Revised NOV2007 - 4 - 5. DUMMY COORDINATE SYSTEMS The definition of the dummy coordinate system given in SAE J211 will be used. A coo
20、rdinate system can be affixed to any point on the dummy. The coordinate system will translate and/or rotate with the dummy part to which it is attached during the test. To define standard orientations of the coordinate axes, the dummy will always be considered as standing erect. For this posture, th
21、e +x-axis will be directed forward, the +y-axis will be directed from the dummys left to its right side and the +z-axis will be directed downward from head to toe. In anatomical terminology, the +x-axis is directed from posterior to anterior (P-A), the +y-axis is directed from left to right (L-R), a
22、nd the +z-axis is directed from superior to inferior (S-I). Figure 5 shows examples of this standardized orientation for coordinate systems attached to a few body points. Note that as the dummy is articulated to sit in a vehicle or during a test the coordinate systems rotate with their respective du
23、mmy parts. FIGURE 5 - ORIENTATIONS OF STANDARDIZED DUMMY COORDINATE SYSTEMS FOR STANDING AND SEATED POSTURES Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Revised NOV2007 - 5 - 6. STANDAR
24、D POLARITIES FOR RECORDED DUMMY MEASUREMENTS 6.1 Polarities of Acceleration, Velocity, and Displacement Positive recorded outputs for these transducers are to be consistent with the positive axes of the coordinate system defined for the specific dummy or vehicle point being measured. In general, for
25、 any dummy component oriented in its standard standing position, blows to its back side, left side, and top will produce positive accelerations relative to its +x, +y, and +z directions, respectively. As illustrated in Figure 6, a blow to the back of the dummys head produces an acceleration in the f
26、orward direction (+x) which should be recorded as a positive acceleration. A blow to the top of the head produces a +z acceleration. A blow to the left side of the head produces a +y acceleration. Note that since the SID dummy is only instrumented to measure accelerations, the polarities of its tran
27、sducers are determined by the methods described in this section. FIGURE 6 - HEAD IMPACT DIRECTIONS THAT PRODUCE POSITIVE HEAD ACCELERATIONS RELATIVE TO THE HEAD COORDINATE SYSTEM For relative displacement of body parts, the coordinate system of interest must be defined. For example, frontal chest co
28、mpression is the distance that the sternum moves relative to the thoracic spine. In this case, the coordinate system is fixed to the thoracic spine. When the sternum moves closer to the spine, its displacement is rearward relative to the spine which is in the negative x-direction. Hence, the polarit
29、y for chest compression is negative. For lateral chest compression, a blow to the left side of the chest produces a positive displacement of the impacted ribs relative to the thoracic spine. However, a blow to the right side of the chest produces a negative rib displacement. The directions of these
30、chest compressions are illustrated in Figure 7. The rearward displacement of the tibia relative to the femur that is measured by the knee shear transducer is in the negative x-direction. The polarity for this motion is negative. Copyright SAE International Provided by IHS under license with SAENot f
31、or ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Revised NOV2007 - 6 - FIGURE 7 - DIRECTIONS OF FRONTAL AND LATERAL CHEST COMPRESSIONS 6.2 Polarities of Measured External Loads For load cells that measure loads applied directly to the dummy or vehicle structure
32、, their recorded output polarities should be consistent with the direction of the applied external load referenced to the standardized coordinate system at the point of the load application. For example, load cells that measure shoulder belt loading of the clavicle are designed to measure Fxand Fzap
33、plied to the clavicle. The rearward (-x) component of the shoulder belt force applied to the clavicle should be recorded with a negative polarity. The downward (+z) component should have a positive polarity. For the BIOSID, a lateral inward load applied to the crest of the left illium (+y) would be
34、positive, while a lateral inward load applied to the crest of the right ilium (-y) would be negative. 6.3 Polarities of Measured Internal Loads Defining recorded output polarities for load cells that measure loads internal to the dummy requires a standardized dummy sectioning scheme and a definition
35、 of what sectioned dummy part is to be loaded in the positive direction since internal loads occur in pairs of equal magnitudes but opposite directions. The standardized sectioning scheme is illustrated by the free-body diagram of a cube shown in Figure 8. It is assumed that the load cell of interes
36、t is contained within the cube and responds to loads applied to the surfaces of the cube. Load cell outputs should be recorded with positive polarities when normal loads, shear loads, torques, or moments are applied in the positive direction, as defined by the standardized coordinate system, to the
37、right, front, and/or bottom surfaces of the cube. These loads are represented by solid arrows. For static equilibrium, equal magnitude but opposite direction loads (negative) must be applied to the left, back, and/or top surfaces of the cube as indicated by the dashed arrows. For example, upper and
38、lower neck, lumbar spine, and upper and lower tibia load cells should have positive recorded outputs when the dummy is sectioned below the load cell in question and positive loads are applied to the bottom surface of the sectioned body part that contains the load cell in question. Dummy manipulation
39、s for checking the recorded polarities of the outputs of various transducers are given in Section 7. Free-body diagrams for specific dummy load cells showing the load systems that produce the required outputs that should be recorded with the specified polarities are given in Section 8. Copyright SAE
40、 International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Revised NOV2007 - 7 - FIGURE 8 - FREE-BODY DIAGRAM OF A SECTIONED DUMMY PART CONTAINING THE LOAD CELL OF INTEREST (ILLUSTRATED AS A CUBE). PRINCIPLE AXES
41、OF LOAD CELL ALIGNED PARALLEL TO RESPECTIVE AXES OF LOCAL DUMMY COORDINATE SYSTEM. BOLD ARROWS OF NORMAL FORCES (F), SHEAR FORCES (S), AND MOMENTS (M) SHOWN IN POSITIVE DIRECTIONS AND APPLIED TO THE FRONT, RIGHT, AND BOTTOM SURFACES OF THE CUBE. DOTTED ARROWS INDICATE DIRECTION OF LOADS APPLIED TO T
42、HE BACK, LEFT, AND TOP SURFACES FOR STATIC EQUILIBRIUM. ALL LOAD CELL OUTPUTS FOR THIS LOAD SYSTEM TO BE RECORDED WITH POSITIVE POLARITIES. 6.4 Example of Internal vs External Loads A test to determine an external vs internal load cell is as follows. An internal load cell measures forces and moments
43、 between two body segments. A Eurosid shoulder load cell is mounted between the arm and clavicle and is considered internal. This load cell will also measure an external impact to the shoulder but the internal rule take precdence. The 10 year old shoulder load cell is an external load cell. Although
44、 the load cell is mounted within the shoulder structure, it will only measure the external forces applied to the shoulder from the shoulder belt. Forces from the arm are not measured. 7. DUMMY MANIPULATIONS FOR CHECKING POLARITIES OF MEASURED LOADS Table 1 contains descriptions of dummy manipulation
45、s that can be used to verify the correctness of the polarities of recorded outputs for some of the more common load cells used in dummies. Copyright SAE International Provided by IHS under license with SAENot for ResaleNo reproduction or networking permitted without license from IHS-,-,-SAE J1733 Re
46、vised NOV2007 - 8 - TABLE 1 - DUMMY MANIPULATIONS FOR CHECKING RECORDED LOAD CELL POLARITY RELATIVE TO SIGN CONVENTION Load Cell Measure Dummy Manipulations Polarity Upper FxHead Rearward, Chest Forward + and FyHead Leftward, Chest Rightward + Lower FzHead Upward, Chest Downward + Neck MxLeft Ear To
47、ward Left Shoulder + Loads MyChin Toward Sternum + MzChin Toward Left Shoulder + Left Shoulder FxArm Rearward, Chest Forward + Loads (SID IIs, FyArm Leftward, Chest Rightward + ES2, WorldSID) FzArm Upward, Chest Downward + Right Shoulder FxArm Forward, Chest Rearward + Loads (SID IIs, FyArm Rightwar
48、d, Chest Leftward + ES2, WorldSID) FzArm Downward, Chest Upward + Right Clavicle Loads FxShoulder Forward, Chest Rearward + (Internal LC) FzShoulder Downward, Chest Upward + Left Clavicle Loads FxShoulder Rearward, Chest Forward + (Internal LC) FzShoulder Upward, Chest Downward + Upper FxChest Rearward, Pelvis Forward + and FyChest Leftward, Pelvis Rightward + Lower FzChest Upward, Pelvis Downward + Lumbar MxLeft Shoulder Toward Left Hip + Spine MySternum Toward Front of Legs + (All ATDs) MzRight Shoulder Forward, Left Shoulder Rearward
