1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14684 Force-Deflection Characteristics of Elastomeric Components, Hysteresis Determination Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 1 of 10 1 Scope Note: Nothing in this standard supercedes applicable laws and regu
2、lations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. Determination of hysteresis of elastomeric components. The test according to this test procedure provides information on the viscous-elastic behavior and the da
3、mpening capacity of the elastomers used. 1.2 Foreword. Determination of stress ability of the elastomeric components in the installation position in vehicles and in accordance with the installation conditions. 2 References Note: Only the latest approved standards are applicable unless otherwise spec
4、ified. 2.1 External Standards/Specifications. DIN 862 DIN 878 ISO 9513 DIN 876-2 ISO 7500-1 2.2 GM Standards/Specifications. GMW14734 3 Resources 3.1 Facilities. Not applicable. 3.1.1 Calibration. The test facilities and equipment shall be in good working order and shall have a valid calibration lab
5、el. 3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuring variables as specified in this standard shall be determined correctly with respect to their physical definition. 3.2 Equipment. 3.2.1 Test Equipment. 3.2.1.1 Testing Machine Universal testing m
6、achine for stressing of elastomeric components up to 50 kN maximum with constant velocity (v) (maximum deviation 10%), The test machine shall fulfill the following requirements: The force measuring device of the test machine shall correspond to ISO 7500-1. The deflection measuring device shall corre
7、spond to ISO 9513. Accuracy of: Force Measurement: 1.5% of the relevant value. Deflection measurement: 0.05 mm. 3.2.1.1.1 Total deformation of universal testing machine frame, testing and clamping devices etc., 1% of deformation of the elastomeric components subjected to force Fmax (+Fv). In this ca
8、se, correction of the measurement results by the deformation of the testing machine is not necessary. 3.2.1.1.2 If the deformation of universal testing machine frame, testing and clamping devices etc., is within the range 1% to 10% of deformation of the elastomeric components, then correction of the
9、 measurement results shall be performed. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14684 Copyright 2013 General Motors Company All
10、Rights Reserved January 2013 Page 2 of 10 3.2.1.1.3 Measurements with testing equipment, in which deformation 10% of the deformation of the elastomeric components are not permissible. Note: The measurement of deformation of the testing equipment shall be performed using a rigid substitute body under
11、 the same testing and configuration parameters as the component measurement. However, the velocity vi shall be selected according to the application. The correction measurement shall cover the entire evaluation area. The rigid substitute body is defined as the outer contour of the elastomeric compon
12、ent pressed into the corresponding component mount, according to the relevant component drawing, with an inserted pin. The pin shall be tightened to the specified torque according to the elastomeric component drawing. 3.2.1.2 Environmental Chamber with Recirculated Air for Use on the Universal Testi
13、ng Machine. Temperature range: -30 C to + 150 C, continuously adjustable. Temperature stability: 2 C. Rate of change in temperature for the empty environmental chamber; 1.5 C/minute recommended value. 3.2.1.3 Pre-conditioning Chamber with Recirculated Air. Temperature range: -30 C to + 150 C, contin
14、uously adjustable. Temperature stability: 2 C. Rate of change in temperature for the empty pre-conditioning chamber: 1.5 C/minute recommended value. 3.2.1.4 Measuring plate according to DIN 876-2 made of cast iron, 400 mm 400 mm. 3.2.1.5 Testing and clamping devices for installing and fastening the
15、elastomeric components on the universal testing machine. Roller tables and roller or ball straight-line mechanisms for forces up to 10 kN. 3.2.1.6 Timer with a display range of 168 h and a reading accuracy of one (1) minute. 3.2.1.7 Dimensional Measuring Equipment. 3.2.1.7.1 Dimensional change measu
16、ring instrument, e.g., dial gauge according to DIN 878 with a display range of 10 mm, a measuring accuracy of 0.01 mm and constant measuring force over the measuring path of 2 N. 3.2.1.7.2 Dimensional measuring instrument, e.g., caliper gauge according to DIN 862. 3.2.1.7.3 Dimensional measuring ins
17、trument, e.g., high-accuracy marking gauge with fine adjustment of the slider, vernier 0.1 mm, marking height 500 mm maximum. 3.3 Test Vehicle/Test Piece. 3.3.1 Test Material. 3.3.1.1 Test Sample Form. Test samples are elastomeric components (elastomeric components or elastomeric/metal components),
18、which are used as components in vehicles. 3.3.1.2 Number of Test Samples. At least three (3) test samples shall be tested. 3.4 Test Time. Not applicable. 3.5 Test Required Information. Not applicable. 3.6 Personnel/Skills. Not applicable. 4 Procedure Summary of Test Method. Testing of the deformatio
19、n of elastomeric components for vehicles (elastomeric components or elastomeric/metal components) with constant velocity in the temperature range of -30 C to + 150 C. 4.1 Preparation. 4.1.1 Test Sample Preparation. For initial sampling and in cases of arbitration, the test shall be performed no earl
20、ier than seven (7) days, and for continuous quality control no earlier than 72 h, after vulcanization. Before testing, the test samples shall be stored in an unstressed condition for at least 8 h at +23 C 5 C. 4.2 Conditions. 4.2.1 Environmental Conditions. Copyright General Motors Company Provided
21、by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14684 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 3 of 10 4.2.2 Test Conditions. Deviations from th
22、e requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. This includes, but not limited, to deviations from the test sample pre-treatment, the technical data of the testing equipment, the stressing times
23、 and the test temperatures. 4.3 Instructions. 4.3.1 Test Procedure. 4.3.1.1 General. The test sample shall be tested according to the data shown in the test specifications and the design drawings of the elastomeric component with regard to installation instructions, stressing devices, etc., as well
24、as in accordance with the relevant test procedure. Between two tests on the same test sample, a period of at least 24 h shall elapse. Before testing, the weight of the test sample, the testing and clamping devices etc., shall be compensated on the universal testing machine, if this has an influence
25、on the force display or the forces Fji and Fjl. 4.3.1.2 Determination of Height hj0i. The height hj0i shall be measured according to GMW14734 at +23 C 5 C, if this value is required for the elastomeric component. 4.3.1.3 Conditioning. The test samples shall be pre-conditioned according to the specif
26、ied test type in 4.3.1.5 and shall be subsequently tested at the specified temperature for this test type per 4.3.1.4 through 4.3.1.4.2.2.5. 4.3.1.4 Test Procedure. 4.3.1.4.1 The test sample shall then be attached to the pre-heated or pre-cooled test device, and the height hjei shall be determined a
27、fter a 30 1 minutes conditioning period. 4.3.1.4.2 The spring characteristic shall then be determined by one of the methods detailed in 4.3.1.4.2.1 or 4.3.1.4.2.2. 4.3.1.4.2.1 The method of determination according to Appendix A, Figure A1. 4.3.1.4.2.1.1 The test piece shall be stressed with a force
28、Fji = Fjvi and the height of the elastomeric component hjvi and its initial deflection sjvi shall be determined. Reset the force and displacement measuring equipment to zero. 4.3.1.4.2.1.2 The force Fji = Fjvi shall be increased to Fji = Fjvi + Fji max at a velocity vji. 4.3.1.4.2.1.3 The force Fji
29、= Fjvi+ Fji max shall be decreased until Fji = Fjvi + Fji min at the same velocity. 4.3.1.4.2.1.4 Again, increase the force Fji = Fjvi+ Fji min to Fji = Fjvi+ i max at a velocity vji. 4.3.1.4.2.1.5 Repeat the unloading and loading of the force as described in 4.3.1.4.2.1.3 and 4.3.1.4.2.1.4 two (2)
30、more times. 4.3.1.4.2.2 The method of determination shall be performed according to Appendix A, Figure A2. 4.3.1.4.2.2.1 Set the force measuring equipment to Fji = 0 and Fjl = 0. The displacement measuring equipment shall be set to sji = 0 and sjl = 0 and proceed according to Appendix A, Figure A2 a
31、nd per 4.3.1.4.2.2.2 through 4.3.1.4.2.2.5. 4.3.1.4.2.2.2 The force Fji = 0 shall be increased to Fji = Fjgi at a velocity vji. 4.3.1.4.2.2.3 The test piece shall be stressed from Fji = Fjgi to Fjl = Fjgl at a velocity vjl = vji. 4.3.1.4.2.2.4 The force shall be increased from Fjl = Fjgl to Fji = Fg
32、i at a velocity vji. 4.3.1.4.2.2.5 Repeat the unloading and loading of the force as described in 4.3.1.4.2.2.3 and 4.3.1.4.2.2.4 two (2) more times. 4.3.1.5 Conditioning and Test Temperatures. According to agreement, one of the conditions listed in Table 1 for conditioning and test temperatures shal
33、l be used for performing the test. The test type is specified on the drawings, and test, and material specifications. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDW
34、IDE ENGINEERING STANDARDS GMW14684 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 4 of 10 Table 1: Conditioning and Test Temperatures Test Type Conditioning Time in Hours Conditioning and Test at Temperature in C Without Letter 8 +23 5 A 168, -2 -30 3 B 72, -2 -30 3 C 3,
35、 +1 -30 3 D 168, -2 -20 3 E 72, -2 -20 3 F 3, +1 -20 3 G 168, -2 -10 3 H 72, -2 -10 3 I 3, +1 -10 3 K 3, +1 +23 5 L 3, +1 +50 3 M 3, +1 +70 3 N 3, +1 +80 3 O 3, +1 +100 3 P 3, +1 +125 3 Q 3, +1 +150 3 5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. Not applicable. 5.3 Test Do
36、cumentation. 5.3.1 Evaluation and Rating. 5.3.1.1 Record the initial curve Fji = f (sji) on the force-deflection characteristic. 5.3.1.2 Record the spring characteristic on the force-deflection characteristic during the first stress cycle. 5.3.1.3 Determine of displacements sjhi and sjhl during the
37、first and third stress cycles. 5.3.1.4 Determine of displacements sjfi and sjfl. 5.3.1.5 Determination of the spring rate cji at the point Pi, cjl at the point Pl, cji at the point Pi and cjl at the point Pl of the spring characteristic during the first stress cycle. Note: For tolerance specificatio
38、ns, the hysteresis according to 5.3.1.2, as well as sjhi, sjhl, sjfi, sjfl, cji at the point Pi, cji at the point Pi, cjl at the point Pl, cjl at the point Pl and the height hjei shall be used. 5.4 Report. With reference to this standard, the test report shall also include the following. Part name.
39、Part number or drawing number. Test specification number, additional identification. Grade of elastomer. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERI
40、NG STANDARDS GMW14684 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 5 of 10 Manufacturer, date of manufacture. Date of test, test sample serial number. Furthermore, the following shall be specified. Initial force Fjvi in newtons (N). Forces Fji min, Fji max, Fjgi and Fj
41、gl in newtons (N). Velocity vji in meters per second (m/s). Points Pi, Pi, Pl and Pl Initial curve Fji = f (sji) to 5.3.1.1. Hysteresis to 5.3.1.2. The individual values of the following, rounded to one decimal place. Height hj0i in millimeters (mm). Height hjvi in millimeters (mm). Height hjei in m
42、illimeters (mm). Deflection sjvi in millimeters (mm). Deflections sjhi and sjhl in millimeters (mm) according to 5.3.1.3. Deflections sjfi and sjfl in millimeters (mm) according to 5.3.1.4. Spring rates cji (cji) at the point Pi (Pi) in newtons per millimeter (N/mm) according to 5.3.1.5. Spring rate
43、s cjl (cjl) at the point Pl (Pl) in newtons per millimeter (N/mm) according to 5.3.1.5. Any specific observations on the test sample (e.g., crushing folds, cracks, or other surface changes). 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not pro
44、pose to address all the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Deflection s: The deflection s is
45、that deflection covered by the force application point during deformation of the elastomeric component under force F. It is determined in the direction of application of force F. Deflection sf: The deflections sf describes the change in position of the intersection of the force-deflection curve with
46、 the displacement axis between the 1st and the 3rd stress cycle, due to the flow characteristics of the elastomeric component. Deflection sh: The deflections sh shall indicate the positions on the displacement axis where the force-deflection curve intersects it of the first stress cycle Deflection s
47、v: The deflection sv is that deflection covered by the force application point in the direction of application of initial force Fv, when the elastomeric component is subjected to the initial force Fv Force Application Point: The force application point is the position on the moveable traverse of the
48、 universal testing machine taken as a point, to which the elastomeric component or the testing and clamping device is coupled. The force application point lies in the direction of application of force F and may be e.g., a screw thread, a pressure plate or a clamping head. Force F: The force F is the
49、 force to which the elastomeric component to be tested is subjected. Its value and direction of application are determined by the installation conditions of the elastomeric component. Force Fg: Force Fg shall be the limit of the force F applied to the elastomeric component. Force Fmax: The force Fmax is the ma
