1、GM DAEWOO Auto & Technology EDS Engineering, GM DAEWOO Auto & Technology Standards DETERMINATION OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTERISIS OF ELASTOMERIC COMPONENTS Do Not Use on New Programs. Being Replaced by GMW14684 EDS-T-7404 ISSUED DATE: 1991. 12. 16 REVISED DATE: 2008. 1
2、0. 15 VERSION: 5 (Superceded) EDS-T-7404DETERMINATION OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTERISIS OF ELASTOMERIC COMPONENTS PAGE: 1/9 ISSUED DATE: 1992. 12. 16 REVISED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 pr
3、oject (incl. CKD Program). It is Superceded for all future projects and replaced by GMW14684. 1. PURPOSE This standard is the test method which determines the force-deflection characteristics of elastomeric components used in vehicles in the temperature range of -30 to +150 under a constant velocity
4、. 2. SCOPE The determination of the force-deflection curve of elastomeric components. This test will also give some indication of the relative creep properties of elastomer. 3. DEFINITION 3.1. Force F The force F shall be the force applied to the elastomeric component. Its magnitude and direction sh
5、all correspond with the installation conditions of the component. 3.2. Initial force FvThe initial force Fvshall be the force initially applied to the elastomeric component in order to establish a initial datum point for measurements. Its magnitude is normally 1% to 2% of force max F, and shall act
6、in the same direction as force max F. 3.3. Force max F The force max F shall be the maximum force F which the elastomeric component is stressed in addition to the initial force Fv. 3.4. Force min F The force min F shall be the minimum force F applied to the elastomeric component during hysteresis me
7、asurement. 3.5. Force FgThe force Fgshall be the limit of the force F applied to the elastomeric component. When the direction is the same as the loading direction indicated in the drawing, It has (+) value. In case of opposite direction, it has (-) value. 3.6. Height hoIt shall be determined on the
8、 unstressed elastomeric component prior to the application of any force. 3.7. Initial height hvThe initial height hvshall be a dimension in the direction of the force F, determined under the initial force Fvacting on the elastomeric component. EDS-T-7404DETERMINATION OF FORCE-DEFLECTION CHARACTERIST
9、ICS AND LOW VELOCITY HYSTERISIS OF ELASTOMERIC COMPONENTS PAGE: 2/9 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 3.8. Height heThe height heshall be a dimension in the direction of the force F, which is measured 0.5 hours after the elastomeric component
10、 is fixed to the test device. If in so doing, the elastomeric component must be strained. 3.9. Force-application point The force-application point shall be the position (taken as a point) on the moving head of the universal testing machine to which the elastomeric component or test fixture is attach
11、ed. The force-application point is located along the direction of application of the force max F. 3.10. Velocity VThe velocity Vshall be the constant velocity with which the force-application point moves in the direction of application of the force F. 3.11. Deflection s The deflection s shall be the
12、 distance through which the force-application point moves under the force F during deformation of the elastomeric component. It is measured in the direction of application of the force F. 3.12. Initial deflection svThe deflection svshall be the distance through which the force-application point move
13、s under the initial force Fvduring deformation of the elastomeric component. It is measured in the direction of the elastomeric component. 3.13. 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. 3.14. Spring r
14、ate c(c) The spring rate c(c) is the slope of the tangent at a point P(P)(specified on drawings) on the force-deflection curve. The spring rate c(c) is determined by the relationship )(SFCSFC =and the point P(P) by one of the two values F or s, with reference to the force-deflection curve. 3.15. Ini
15、tial curve The initial curve is the force-deflection curve obtained during the first stress cycle from F=Fvto F=Fv+ max F, respectively from F=0 to F=Fgon the elastomeric component. 3.16. Hysteresis The hysteresis is the degree to which the deflection of the elastomeric component lags behind the def
16、orming force. The degree is shown on the force-deflection curve by the width of the loop. In case of this test method, the hysteresis loop is not closed. 3.17. Displacement shThe Displacement shshall indicate the position on the displacement axis where the force-deflection curve EDS-T-7404DETERMINAT
17、ION OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTERISIS OF ELASTOMERIC COMPONENTS PAGE: 3/9 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology intersects it of the first stress cycle. 3.18. Displacement sfThe displacement sfshall be the change in
18、position of the intersection of the force-deflection curve with the displacement axis, due to creep in the elastomeric component, which occurs during the first three consecutive stress cycles. 3.19. Suffixes To identify the forces or dimensions being applied or determined, and their direction, alpha
19、betical and numerical suffixes shall be used. 3.19.1. Alphabetical subscripts shall be used to identify the type of force or dimensions, e.g) ho: a dimension of the unstressed elastomeric component Fv: the force initially applied 3.19.2. Alphabetical suffixes shall be used to identify the test condi
20、tion as defined by clause 6.5. generally designated by j. j may take the form A, B, C,-Q, e.g) FG : denotes a force F given under the conditions denoted by test type G. 3.19.3. Numerical subscripts shall be used to identify the direction in which a force is applied, and shall be generally designated
21、 i and 1. i and 1 may take the form 1, 2, 3, -n. The numerical subscripts shall follow the alphabetical subscripts, 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 samples s
22、hall be elastomeric components, as assembled into the vehicle. 4.2. Test sample quantity At least 3 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
23、 quality control purposes, the period shall be min 3 days. The test samples shall remain at a temperature of 235 for at least 8hours before testing, and shall be free from strain during this period. 5. TESTING DEVICES EDS-T-7404DETERMINATION OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTE
24、RISIS OF ELASTOMERIC COMPONENTS PAGE: 4/9 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 5.1. Universal testing machine. A universal testing machine(hereafter referred to as “the testing machine“) shall be capable of stressing elastomeric components to a
25、maximum force of 50 kN at a constant velocity (max deviation 10%). The testing machine shall comply with DIN 51220, 51221 sheet 1 to 3, DIN 51223, 51227, or BS 1610, and also comply with the following requirements accuracy of The force measuring equipment : 1.5% of the measured value Displacement me
26、asuring equipment : 0.05mm 5.2. Environmental chamber for use on the testing machine The environmental chamber shall be of the air-circulating type, and comply with the following requirements Available temperature range : -30 to +150 Temperature variation : 2K Temperature change rate : 1.5K/minute f
27、or empty cabinet 5.3. Surface plate of cast iron, approximately 400 mm2. Suitable fixtures for locating and attaching the elastomeric components to the testing machine. 5.4. Dimensional measuring equipment 5.4.1. Dimensional change measuring equipment, e.g. a linear dial gauge to DIN 878, BS 907, wi
28、th a range of 10mm, an accuracy of 0.01mm, and extending a relatively constant force of less than 2 N over its range of travel. 5.4.2. Dimensional measuring equipment, e.g. gauge blocks to DIN 862 or BS 4311. 5.4.3. Dimensional measuring equipment, e.g. precision height vernier accurate to 0.1mm, he
29、ight max. 500mm. 6. TEST METHOD 6.1. General The test sample shall 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 a addition to this test method. A period o
30、f at least 24 hours shall elapse between successive tests on the same test sample. If the forces Fji, or Fj1, or the load indicating device on the testing machine is influenced by the weight of the test sample and/or its fixtures, compensation shall be made prior to the commencement of the test. 6.2
31、. Determination of the height(hjoi) Measure the height hjoiat 235 using the method specified in EDS-T-7143(test method for force-deflection and creep deflection), if required. 6.3. Conditioning and test temperature EDS-T-7404DETERMINATION OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTERIS
32、IS OF ELASTOMERIC COMPONENTS PAGE: 5/9 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology One of the following conditioning periods shall be applied, as specified on the relevant component drawings, test specifications or specifications. The test shall then b
33、e carried out at the conditioning temperature. 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 +1
34、080 2.5 O 3 +10100 2.5 P 3 +10125 2.5 Q 3 +10150 2.5 6.4. Procedure 6.4.1. The test sample shall then be attached to the conditioning device(pre-heated or pre-cooled test device), and the height hjeidetermined after a (301) minutes conditioning period. 6.4.2. The force-deflection curve shall then be
35、 determined by one of methods detailed in clause 6.4.2.1 and 6.4.2.2. (1) The method which determines the hysteresis, shown in clause 13.1. 1) Apply a force Fji= Fjviand determine the height of the elastomeric component hjviand its initial deflection sjvi. Reset the force and displacement measuring
36、equipment to zero. 2) Increase the force Fjifrom Fji= Fjvito Fji= Fjvi+ max Fjiat a velocity vji3) Reduce the force Fji= Fjvi+ max Fjiuntil Fji= Fjvi+ min Fji, at the same velocity vji. 4) Again increase the force Fjiuntil Fji= Fjvi+ max Fji, at the same velocity. 5) Repeat the unloading and loading
37、 of the force as described in 1) to 4) two more times. (2) The method which determines the hysteresis, shown in clause 13.2. 1) Reset the force and displacement measuring equipment to zero. 2) Increase the force Fjifrom Fji= 0 to Fji= Fjgiat a constant velocity vji. 3) Reduce the force to zero and s
38、ubsequently increase the force Fjifrom Fji= 0 to Fjl= Fjgl, at a velocity vjl= vji. 4) Again reduce the force to zero and subsequently increase the force Fjifrom Fji= 0 to Fji = Fjgiat a constant velocity vji. 5) Repeat the unloading and loading of the force as described in 3) to 4) two more times.
39、EDS-T-7404DETERMINATION OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTERISIS OF ELASTOMERIC COMPONENTS PAGE: 6/9 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 7. EVALUATION 7.1. Record the initial curve of Fji = f(sji) of the force-deflection
40、curve. 7.2. Record the hysteresis determined during the first stress cycle. 7.3. Determine the displacements sjhiand sjh1during the first and third stress cycle. 7.4. Determine the displacement sjfhiand sjf17.5. Determine the spring rate cji, cjl, cji,at the point pi, pl,pi, p1during the first stres
41、s cycle. 7.6. For checking that the test sample is within tolerance allowed, the hysteresis curve determined in clause 7.2, the displacements sjhi, sjj1, sjfi, sjf1, and the spring rates determined in clause 7.5 and height hjeishall normally be used. 8. TEST REPORT In addition to reference being mad
42、e to this test method, the test report shall also include the following data : Part name, part or drawing number, test spec. number, any additional identification, grade of elastomer, manufacturer, date of manufacture, test sample number, date of test. The value of the following : Initial force - Fj
43、vi (N) Force - min Fji,max Fji,Fjgi,Fjg1 (N) Velocity - vji (m/s) Points - Pi, Pi, P1, P1Initial curve - Fji= f(sji) see clause 7.1 Hysteresis - Fji= f(sji) see clause 7.2 The individual values of the following, rounded to one decimal place Height - hjoi(mm) Height - hjvi(mm) Height - hjei(mm) Defle
44、ction - sjvi(mm) Displacement - sjhi, sjh1(mm) see clause 7.3 Displacement - sjfi, sjf1(m,m) see clause 7.4 Spring rate - cji, cj1, cji, cj1(N/mm) see clause 7.5 Any special observations made during the test, e.g. folds, cracks, splits, other visible defects, shall be reported. EDS-T-7404DETERMINATI
45、ON OF FORCE-DEFLECTION CHARACTERISTICS AND LOW VELOCITY HYSTERISIS OF ELASTOMERIC COMPONENTS PAGE: 7/9 ISSUED DATE: 1992. 12. 16 REVISED DATE: 2008. 10. 15 VERSION: 5 GM DAEWOO Auto & Technology 9. CODING SYSTEM The requirements for the force-deflection and hysteresis characteristics of elastomeric
46、components shall be specified on component drawings, test and material specifications, reports, etc., as follows e.g. Force-Deflection Mapping EDS-T-7404 FNv2 = N min FN2= N max FN2 = N FNg3= N FNg4 = N vi= m/s Initial curve FN=f(sN) Test conditions and requirements Test method Designation 10. INSPE
47、CTION OF TEST EQUIPMENT The test equipment shall be calibrated at intervals not exceeding one year, and certification retained. 11. DEVIATIONS Deviations from the requirements of this test method (e.g. test sample preparation, technical details of the testing machine, etc.) shall have been agreed up
48、on these requirements shall be specified on component drawings, and shall be defined in test reports, etc. 12. REFERENCE DIN 862 Gauge block DIN 867 Surface plate DIN 878 Dial gauge DIN 51220 Verification of testing machine DIN 51221 Tensile testing machine DIN 51227 Bending testing machine EDS-T-7134 Determination of the force-deflection characteristics and permanent set of elastormeric components GME 60234 Force-deflection characteristics and low velocity hysterisis deformation of elastic component EDS-T
