1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS Do Not Use on New Programs. Being Replaced by GMW14682 EDS-T-7411 ISSUED DATE: 1991. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 (Supe
2、rceded) EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 1/7 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology Note: This standard may be applied only for current project (incl. CKD Program). It is Superceded
3、for all future projects and replaced by GMW14682. 1. PURPOSE This standard is test method that determines the deformation characteristics of elastomeric components used in vehicles in the temperature range -30 to +150 under a constant velocity. 2. SCOPE 2.1. The determination of the force-deflection
4、 curve of elastomeric components. This test will also give some indication of the permanent creep properties of the elastomer. 2.2. The determination of the force required to act on the elastomeric component in order to strain it to the vehicle installation conditions. 3. DEFINITION 3.1. Uni-axial s
5、tress Single axial load refers to loading in one direction to a rubber part. 3.2. Force F The force F shall be the force applied to the elastomeric component. Its magnitude and direction shall correspond with the installation conditions of the component. 3.3. Initial force FvThe initial force Fvshal
6、l be the force initially applied to the reference point of elastomeric components in order to establish test results. Its magnitude is normally 1 to 2% of force max F, and it shall act in the same direction as force max F. 3.4. Force max F The force max F is the maximum force F with which the elasto
7、meric component is stressed in addition to the initial force Fv. 3.5. Height hoThe height hoshall be the height of the component measured in the direction of the force F, determined on the unstressed elastomeric component prior to the application of any force. 3.6. Initial Height hvThe initial heigh
8、t hvshall be the height of the component determined under the initial force Fvacting on the component. EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 2/7 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 3.7
9、. Force-application point The force-application point is the position on the moving head of the universal testing machine to which the elastomeric component or test fixture is attached. The force-application point is located along the direction of application of the force max F. 3.8. Velocity v The
10、velocity v is the constant velocity with which the force-application point moves in the direction of application of the force F. 3.9. Deflection s The deflection s is the distance through which the force-application point moves under the force F during deformation of the elastomeric component. It is
11、 measured in the direction of application of the force F. 3.10. Initial deflection svThe initial deflection svis the distance through which the force-application point moves under the initial force Fvduring deformation of the elastomeric component. It is measured in the direction of application of t
12、he initial force Fv. 3.11. Force-deflection curve F=f(s) The force-deflection curve F=f(s) is the mapping of the relationship between the force F and the deflection s, where the applied force is gradually increased from F = Fvto F = Fv+ max F. 3.12. Spring rate c The spring rate c is the slope of th
13、e tangent at a point P(e.g. specified on drawings) on the force-deflection curve. The spring rate c is determined by the relationship sFC=, and the point P is indicated as either force or deflection on the force-deflection curve. 3.13. Stress cycle A stress cycle shall consists of a constant increas
14、e of the load acting on the rubber part from F = FV to F = FV+ max F and subsequent constant decrease to F = FV. 3.14. Initial curve The initial curve is the curve obtained during the first stress cycle. 3.15. Displacement sfThe displacement sfis the distance through which the force-application poin
15、t moves, and measured from the commencement of the first stress cycle to the end of the third stress cycle. The stress cycles shall be consecutive. The displacement sfmay be influenced by the creep properties of the elastomer. 3.16. Suffixes To identify the forces or dimension being applied or deter
16、mined, and their directions, alphabetical and numerical EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 3/7 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology suffixes shall be used. 3.16.1. Alphabetical subsc
17、ripts shall be used to identify the type of force or dimension, e.g. ho- a dimension of the unstressed elastomeric component. Fv- the force initially applied. 3.16.2. Alphabetical suffixes shall be used to indicate the test conditions specified in clause 6.5, and generally designated by j. j may tak
18、e the form A, B, C -Q. e.g. FG - denotes a force F given under the conditions denoted by test type G. 3.16.3. Numerical subscripts shall be used to identify the direction in which a force is applied, and generally designated by i. i may take the form 1, 2, 3 -n. The numerical subscripts shall follow
19、 the alphabetical subscript. e.g. ho1, FCv3, FA1. If there is only one direction of force application, the numerical subscript 1 can be excluded. e.g. FA, Fv4. TEST SAMPLES 4.1. Test sample form The test sample shall be the piece of elastomeric components attached into the vehicle. 4.2. Test sample
20、quantity At least three test samples shall be tested. 4.3. Test sample conditioning For initial sample approval and arbitration purposes, the minimum time period between vulcanization and testing shall be 7 days. For routine quality control purposes, the period shall be 3 days. The test sample shall
21、 be remained at temperature of 235K for at least 8 hours before testing, and shall be free from strain during this period. 5. APPARATUS 5.1. Universal testing machine The universal testing machine(hereafter referred to as “the testing machine“) shall be capable of stressing elastomeric components to
22、 a maximum force of 50kN at a constant velocity(max deviation 10%). The testing machine shall comply with DIN 51220, 51221 sheet 1 to 3, DIN 51223, PS #4 BOE BMTP NFFU UIF GPMMPXJOH SFRVJSFNFOUT accuracy The force measuring equipment : 1.5% of the measured value. Displacement measuring equipment : 0
23、.05mm EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 4/7 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 5.2. Chamber for environmental test & Preconditioning The environmental chamber shall be of the air-
24、circulating type, and meet the following requirements: Temperature range : -30 to +150 Temperature variation : 2K Temperature change rate : at least 1.5K/minute for empty cabinet 5.3. Surface plate of cast iron, approximately 400mm2. 5.4. Suitable fixtures for locating and attaching the elastomeric
25、components to the testing machine 6. PROCEDURE 6.1. General The test sample shall be tested according to the data shown on the test specifications and the relevant component drawings for the elastomeric component regarding method of assembly, direction of stressing, etc., in addition to this test me
26、thod. A period of at least 24 hours shall elapse between successive tests on the same test sample. If the force, on the force indicating device on the testing machine, is indicated owing to the weight of the test sample and/or its fixtures, compensation shall be made prior to the commencement of the
27、 test. 6.2. Determination of the height (hjoi) Measure the height according to EDS-T-7134(force change and permanent change test method), if required. 6.3. Conditioning One of the following conditioning periods shall be applied shown on Table 1, as specified on the relevant component drawing, test s
28、pecification or material specification. The test shall then be carried out under the conditioning condition. 6.4. Test method 6.4.1. Stress the test sample with Fji= Fjviand measure sjviand hjviif required. 6.4.2. Reset the force and the displacement respectively to Fi=0, si=0, as indicated with dia
29、gram in clause 12. Gradually increase the force by Fji= max Fji, at a velocity vi(specified on the component drawings), subsequently release it at the same speed(stress curve). Repeat this stress cycle 3 times. 7. EVALUATION 7.1. Record the initial curve Fji= f(sji) of the force-deflection curve. 7.
30、2. Record the 4th curve of force-deflection curve in the range from Fji= Fjvito Fji= Fji+ max Fji, and also record displacement sjfi. EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 5/7 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5
31、GM DAEWOO Auto & Technology 7.3. Determine the spring rate cjiat the point P of the force-deflection curve recorded in clause 7.2. 7.4. For checking that the test sample is within the tolerance allowed, the force-deflection Fji= f(sji) and the displacement sjias determined in clause 7.2, the spring
32、rate cjias determined in clause 7.3 and the height hjoi shall normally be used. The initial point of the tolerance band for the force-deflection curve may be moved along the force-axis of the mapping up to a maximum displacement point. 8. TEST REPORT This test method is made with a reference appende
33、d, and the test report shall include the following data. Record the following values in addition to Part name, part or drawing number, test spec. number, grade of elastomer, manufacturer, date of manufacture, test sample number, date of test. Initial force - Fjvi(N) Force - max Fji(N) Velocity - vi(
34、m/s) Point P Fourth curve - Fji= f(sji) to clause 7.2 The individual values of the following, rounded to one decimal place. Displacement - sjfi(mm) Spring rate - cji(N/mm) Record any specific observations on the test sample, e.g. folds, cracks, splits, other visible defects. 9. CODING SYSTEM The req
35、uirements for the force-deflection characteristics of elastomeric component shall be specified on component drawings, test and material specifications, reports, etc. Force-Deflection Mapping to EDS-T-7411 FNv= N max FN = N vi= m/s Initial curve FN = f (sN) etc. Test condition and requirements Test m
36、ethod Designation 10. INSPECTION OF TEST EQUIPMENT The test equipment shall be calibrated at intervals not exceeding one year, and certification retained. 11. DEVIATIONS EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 6/7 ISSUED DATE: 1992. 12. 16 RE
37、VISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology Deviations from the requirements of this test method (e.g. test sample preparation, technical details of the testing machine, etc) shall have been agreed upon. These requirements shall be specified on component drawings, shall be define
38、d in test reports etc. 12. REFERENCE GME 60232 Force-deflection characteristics of elastomeric components under uni-axial stress EDS-T-7134 Determination of the force-deflection characteristics and permanent set of elastomeric components 13. TYPICAL FORCE-DEFLECTION MAPPING OBTAINED DURING TEST PROC
39、EDURE FOR DETERMINATION OF Fji= f(sji) (Refer also to clauses 6 and 7 of this test method) EDS-T-7411FORCE-DEFLECTION CHARACTERISTICS OF ELASTOMERIC COMPONENTS UNDER UNI-AXIAL STRESS PAGE: 7/7 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 14. TOLERANCES
40、RANGE OF FORCE-DEFLECTION CHARACTERISTICS ON DRAWINGS. Table 1. Test Conditions Conditioning Code Letter Conditioning Time (H) Test Temperature (K)NONE m 8 23 5 A 168 0-2-30 3 B 72 0-2-30 3 C 3 +10-30 3 D 168 0-2-20 3 E 72 0-2-20 3 F 3 +10-20 3 G 168 0-2-10 3 H 72 0-2-10 3 I 3 +10-10 3 K 3 +1023 5 L 3 +1050 2.5 M 3 +1070 2.5 N 3 +1080 2.5 O 3 +10100 2.5 P 3 +10125 2.5 Q 3 +10150 2.5
