1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14682 Force-Deflection Characteristics of Elastomeric Components under Uni-axial Stress Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 1 of 7 1 Scope Note: Nothing in this standard supercedes applicable laws and regulati
2、ons. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. Determination of spring characteristic of elastomeric components. The test according to this test procedure provides information on the viscous-elastic behavior of
3、the elastomers used. Determination of stressability of the elastomeric components in the installation position in vehicles and in accordance with the installation conditions. 1.2 Foreword. Not applicable. 1.3 Applicability. Not applicable. 2 References Note: Only the latest approved standards are ap
4、plicable unless otherwise specified. 2.1 External Standards/Specifications. DIN 862 DIN 878 ISO 7500-1 DIN 876-2 DIN 6370 ISO 9513 2.2 GM Standards/Specifications. GMW14734 3 Resources 3.1 Facilities. Not applicable. 3.2 Equipment. 3.2.1 Test Equipment. 3.2.1.1 Calibration. The test facilities and e
5、quipment shall be in good working order and shall have a valid calibration label. 3.2.1.2 Testing Machine Universal testing machine for stressing of elastomeric components up to 50 kN maximum with constant velocity (v) (maximum deviation 10%). The test machine shall fulfill the following requirement
6、s: The force measuring device of the test machine shall correspond to ISO 7500-1 Class 1. The deflection measuring device shall correspond to ISO 9513 Class 0.2. Force measurement: 1.5% of the relevant value. Deflection measurement: 0.05 mm. 3.2.1.2.1 Total deformation of universal testing machine f
7、rame, testing and clamping devices etc., 1% of deformation of the elastomeric components subjected to force Fmaximum (+ Fv). In this case, correction of the measurement results by the deformation of the testing machine is not necessary. 3.2.1.2.2 If the deformation of universal testing machine frame
8、, testing and clamping devices etc., is within the range 1% to 10% of deformation of the elastomeric components, then correction of the measurement results shall be performed. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or n
9、etworking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14682 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 2 of 7 3.2.1.2.3 Measurements with testing equipment, in which deformation 10% of the deformation of the elastomeric components are
10、 not permissible. Note: The measurement of deformation of the testing equipment shall be performed using a rigid substitute body under the same testing and configuration parameters as the component measurement. However, the velocity (vi) shall be selected according to the application. The correction
11、 measurement shall cover the entire evaluation area. The rigid substitute body is defined as the outer contour of the elastomeric component pressed into the corresponding component mount, according to the relevant component drawing, with an inserted pin. The pin shall be tightened to the specified t
12、orque according to the elastomeric component drawing. 3.2.1.3 Environmental Chamber with Recirculated Air for Use on the Universal Testing Machine. Temperature Range: -30 C to +150 C, continuously adjustable. Temperature Stability: 3 C. Rate of change in temperature for the empty environmental chamb
13、er, 1.5 C/minute recommended value. 3.2.1.4 Pre-conditioning Chamber with Recirculated Air. Temperature range: -30 to +150 C, continuously adjustable. Temperature stability: 3 C. Rate of change in temperature for the empty pre-conditioning chamber, 1.5 C/minute recommended value. 3.2.1.5 Workbench w
14、ith machine vice 160 according to DIN 6370. 3.2.1.6 Measuring plate according to DIN 876-2 made of cast iron, 400 mm 400 mm. 3.2.1.7 Testing and clamping devices for installing and fastening the elastomeric components on the universal testing machine. Roller tables and roller or ball straight-line m
15、echanisms for forces up to 10 kN. 3.2.1.8 Timer with a display range of 168 h and a reading accuracy of one (1) minute. 3.2.1.9 Dimensional Measuring Equipment. 3.2.1.9.1 Dimensional change measuring instrument, e.g., dial gauge according to DIN 878 with a display range of 10 mm, a measuring accurac
16、y of 0.01 mm and constant measuring force over the measuring path of 2 N. 3.2.1.9.2 Dimensional measuring instrument, e.g., caliper gauge according to DIN 862. 3.2.1.9.3 Dimensional measuring instrument, e.g., high-accuracy marking gauge with fine adjustment of the slider, Vernier 0.1 mm, marking he
17、ight 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), which are used as components in vehicles. 3.3.1.2 Number of Test Samples. At least three (3) test samples
18、 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 deformation of elastomeric components for motor vehicles (elastomeric components or elastomeric/metal components) w
19、ith constant velocity in the temperature range of -30 C to +150 C (up to +225 C for other materials than elastomer). 4.1 Preparation. 4.1.1 Test Sample Preparation. For initial sampling and in cases of arbitration, the test shall be performed no earlier than seven (7) days, and for continuous qualit
20、y 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 by IHS under license with General Motors CompanyNo
21、t for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14682 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 3 of 7 4.2.2 Test Conditions. Deviations from the requirements of this standard shall have been agr
22、eed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 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
23、with regard to installation instructions, stressing devices etc., as well as in accordance with the relevant test procedure. Between two (2) 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., sh
24、all be compensated on the universal testing machine, if this has an influence on the force display or the force Fji. 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 Conditioni
25、ng. The test samples shall be pre-conditioned according to the specified test type in 4.3.1.5 and shall be subsequently tested at the specified temperature for this test type as follows. 4.3.1.4 Test Procedure. Stress the test sample with Fji = Fjvi and, if necessary, measure sjvi and hjvi. Set the
26、display of the force measuring device to Fji = 0 and the display of the deflection measuring device to sji = 0. Then, in accordance with the representation in Appendix A, Figure A1, proceed as follows: Stress the test sample additionally with Fji = Fji maximum at velocity vi and subsequently reduce
27、this force by the value Fji maximum at the same speed. Repeat the stress cycle three (3) 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 shall be used for performing the test. The test type is s
28、pecified on the drawings, and test and material specifications. 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/+1 -30 3 D 168/-2 -20 3 E 72/-2 -20 3 F 3/+1 -20 3 G 168/
29、-2 -10 3 H 72/-2 -10 3 I 3/+1 -10 3 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 GMW14682 Copyright 2013 General Motors Company All Right
30、s Reserved January 2013 Page 4 of 7 Test Type Conditioning Time in hours Conditioning and Test at Temperature in C 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
31、 Test Documentation. 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 Fji = f (sji) on the same force-deflection characteristic of Fji = Fjvi to Fji = Fjvi + Fji maximum during the fourth stre
32、ss cycle and also determine the deflection sjfi. 5.3.1.3 Determination of the spring rate cji at the point P of the spring characteristic (5.3.1.2). Note: For tolerance specifications, the spring characteristic Fji = f (sji) and the deflection sji according to 4.3.1.2, as well as the spring rate cji
33、 according to 4.3.1.3 and the height hj0i shall be used. 5.3.1.4 The tolerance range zero point for the spring characteristic Fji = f (sji) can be moved along the abscissa of the force-deflection characteristic via the deflection sjfi maximum. 5.3.2 Report. With reference to this standard, the test
34、report shall also include the following: Part name, part number, or drawing number. Test specification number, additional identification, grade of elastomer, manufacturer, date of manufacture, date of test, test sample serial number. Furthermore, the following shall be specified: Initial force Fjvi
35、in N. Force Fji maximum in N. Velocity, vi in m/s. Point P. Initial curve Fji = f (sji) to 5.3.1.1. Spring characteristic Fji = f (sji) to 4.3.1.2. The individual values of the following, rounded to one decimal place: Height hj0i in millimeters. Height hjvi in millimeters. Deflection sjfi in millime
36、ters. Spring rate cji in N/mm. Any specific observations on the test sample (e.g., crushing folds, cracks, or other surface changes). Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from I
37、HS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14682 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 5 of 7 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated with i
38、ts 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 that deflection covered by the force application point du
39、ring deformation of the elastomeric component under force F. It is determined in the direction of application of force F. Deflection sf: The deflection sf describes the change in position of the force application point which occurs between the start of the 1st and the end of the 3rd stress cycle, du
40、e to the flow characteristics of the elastomeric component. For this purpose, the three stress cycles shall be in direct sequence. Deflection sv: The deflection sv is that deflection covered by the force application point in the direction of application of initial force Fv, when the elastomeric comp
41、onent is subjected to the initial force Fv. Force Application Point: The force application point is the position on the moveable traverse of the universal testing machine taken as a point, to which the elastomeric component or the testing and clamping device is coupled. The force application point l
42、ies 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 force to which the elastomeric component to be tested is subjected. Its value and direction of application are determined by the installation conditions of
43、 the elastomeric component. Force Fmaximum: The force Fmaximum is the maximum value of force F to which the elastomeric component is stressed in addition to the initial force Fv. Height h0: The height h0 is a dimension in the direction of application of force F, which shall be determined on the unst
44、ressed elastomeric component prior to the test. Height hv: The height hv is a dimension in the direction of application of force F, which shall be determined under the initial force Fv acting on the elastomeric component. Initial Curve: The initial curve is the spring characteristic of the first str
45、ess cycle obtained during application on the elastomeric component from F = Fv to F = Fv + Fmaximum. Initial Force Fv: The initial force Fv is the force to which the elastomeric component to be tested is subjected, in order to ensure the absence of play in the testing equipment. It acts in the direc
46、tion of the force F and is 1% to 2% of the force F maximum. Spring Characteristic F = f(s): The spring characteristic F = f (s) is the relationship represented in the force-deflection characteristic, between the force F and the deflection s, where the force varies between F= Fv and a defined maximum
47、 value F = Fv + Fmaximum. Spring Rate c: The spring rate is the slope of the tangent at a defined point P (e.g., specified on the drawing) of the spring characteristic. The spring rate c is determined by the relationship: sFc And the point P, by one of the two (2) variables F or s, in conjunction wi
48、th the spring characteristic. Stress Cycle: The stress cycle is that procedure, during which the elastomeric component is continuously subjected to stress of the order F = Fv to F = Fv + Fmax and subsequently, to a reduced value of F = Fv. Suffixes: For identification of the measured variables and t
49、he direction of force application, alphabetical and numerical suffixes shall be used. Alphabetical suffixes shall be used to identify the type of measured variable. For example: ho = Height of the unstressed elastomeric component. Fv = Initial force. Alphabetical suffixes shall be used to identify the test type outlined in 3.2.1.5, Ta
