1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14683 Force-Deflection Characteristics of Elastomeric Components Under Bi-axial Stress Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 1 of 6 1 Scope Note: Nothing in this standard supercedes applicable laws and regulatio
2、ns. 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 visco-elastic behavior of t
3、he 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 app
4、licable unless otherwise specified. 2.1 External Standards/Specifications. DIN 862 DIN 876 DIN 878 DIN 6370 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
5、 calibration label. 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 Universal Testing Machine. For stressing of
6、 elastomeric components up to 50 kN maximum with constant velocity (maximum deviation 10%), short form in text universal testing machine. Force measurement: 1.5% of the relevant value. Deflection measurement: 0.05 mm. 3.2.1.1 Total deformation of universal testing machine frame, testing and clamping
7、 devices etc. 1% of deformation of the elastomeric components subjected to force Fmax (+ Fv). In this case, correction of the measurement results by the deformation of the testing machine is not necessary. 3.2.1.2. If the deformation of universal testing machine frame, testing and clamping devices e
8、tc., 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 networking permitted without lice
9、nse from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14683 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 2 of 6 3.2.1.3 Measurements with testing equipment, in which deformation 10% of the deformation of the elastomeric components are not permissible. Note: The measur
10、ement 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. 3.2.1.4 The velocity vi shall be selected according to the application. The correction measurement shall cover the entire e
11、valuation area. 3.2.1.5 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. 3.2.1.6 The pin shall be tightened to the specified torque according to th
12、e elastomeric component drawing. 3.2.1.7 A test device for applying an additional constant force Fj to the elastomeric component hereafter referred to as the “test device“. 3.2.1.8 A test device which enables a stress to be gradually applied to the elastomeric component, up to a force Fj = Fvj + Fj
13、max at a constant velocity of 1.25 0.10 10-3 m s-1, and subsequently maintains this force at a constant value. The moment at which the force reaches its maximum value shall be indicated by the test device. The test device shall span a range of force from 50 N to 4000 N with an accuracy of 10 N. 3.2.
14、1.9 Test devices which apply the force by means of suitable masses, such as lever systems, are preferred. 3.2.1.10 Workbench with machine vice 160 DIN 6370. 3.2.1.11 Measuring plate according to DIN 876 made of cast iron, 400 400 mm. 3.2.1.12 Testing and clamping devices for installing and fastening
15、 the elastomeric components on the universal testing machine. Roller tables and roller or ball straight-line mechanisms for forces up to 10 kN. 3.2.1.13 Stop watch or clock with a display range of 600 s and a reading accuracy of 0.1 s. 3.2.1.14 Dimensional Measuring Equipment. 3.2.1.14.1 Dimensional
16、 change measuring instrument, e.g., dial gauge according to DIN 878 with a display range of 25 mm, a measuring accuracy of 0.01 mm and constant measuring force over the measuring path of 2 N. 3.2.1.14.2 Dimensional measuring instrument, e.g., caliper gauge according to DIN 862. 3.2.1.14.3 Dimensiona
17、l measuring instrument, 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/meta
18、l components), 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 4.1 Preparation. 4.1.1 Test Sample
19、 Preparation. For initial sampling and in cases of arbitration, the test shall be performed no earlier than seven 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
20、5 C. 4.1.1.1 Summary of Test Method. Testing of the deformation of elastomeric components for vehicles (elastomeric components or elastomeric/metal components) with constant velocity at + 23 C 5 C. 4.2 Conditions. 4.2.1 Environmental Conditions. 4.2.2 Test Conditions. Deviations from the requirement
21、s of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license
22、 from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14683 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 3 of 6 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
23、drawings of the elastomeric component with regard to installation instructions, stressing devices etc., as well 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 tes
24、ting and clamping devices etc. shall be compensated on the universal testing machine and test device, if this has an influence on the force display or the forces Fi and Fj. 4.3.1.2 Determination of Height h0i. The height h0i shall be measured according to GMW14734 at + 23 C 5 C, if this value is req
25、uired for the elastomeric component. 4.3.1.3 Test Procedure. The test sample shall be stressed with Fj = Fvj at a velocity of 1.25 0.10 103 m/s, the dimensional change measuring equipment shall be set to zero (sj = 0), and the stress shall be reduced with an equal speed to zero Fj = 0. This cycle sh
26、all be repeated until the deflection change under stress Fvj is 0.01 mm (normally three (3) cycles will be sufficient). The zero point of the dimensional change measuring equipment is then fixed. 4.3.1.4 Increase the force, applied to the elastomeric component under test, at a velocity of 1.25 0.10
27、10-3 m/s until the total force of Fj = Fvj + Fj max is applied. This time is t = t0, and shall be indicated by the test device. The measuring period shall commence at this time. The force Fj, applied to the elastomeric component, is maintained at a constant value during the remainder of the test. 4.
28、3.1.5 The test sample shall be stressed 600 s 10 s from time t0, with Fi = Fvi and vi shall be measured if required. Set force indicating equipment to Fi = 0, and displacement indicating equipment to si = 0, then proceed according to diagram in Appendix A, Figure A1. 4.3.1.6 Stress the test sample w
29、ith the additional force Fi = Fi max at the velocity vi, and subsequently reduce the force at the same speed by the value Fi max In addition, at specified values of Fi the relevant values of sj shall be determined. 4.3.1.7 Repeat the stress cycle according to 4.3.1.5, three (3) times. 5 Data 5.1 Cal
30、culations. Not applicable. 5.2 Interpretation of Results. Not applicable. 5.3 Test Documentation. 5.3.1 Evaluation and Rating. 5.3.1.1 Record the initial curve Fi = f (si, Fvj + Fj max) on the force-deflection characteristic. 5.3.1.2 Record the spring characteristic Fi = f (si, Fvj + Fj max) on the
31、same force-deflection characteristic of Fi = Fvi to Fi = Fvi + Fi max during the fourth stress cycle and also determine the deflection sfi. 5.3.1.3 Determination of the spring rate ci at the point P of the spring characteristic (5.3.1.2). Note: For tolerance specifications, the spring characteristic
32、 Fi = f (si, Fvj + Fj max) and the deflection sfi according to 5.3.1.2, as well as the spring rate ci according to 5.3.1.3 and the height h0i shall be used. The tolerance range zero point for the spring characteristic Fi = f (si, Fvj + Fj max) can be moved along the abscissa of the force-deflection
33、characteristic via the deflection sfi max. 5.3.2 Report. 5.3.2.1 With reference to this standard, the test report shall also include the following: Part name. Part number or drawing number. Test specification number. Additional identification. Copyright General Motors Company Provided by IHS under l
34、icense with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14683 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 4 of 6 Grade of elastomer. Manufacturer, date of manufacture. D
35、ate of test. Test sample serial number. 5.3.2.2 Furthermore, the following shall be specified. Initial forces Fvi and Fvj in N. Forces Fi max and Fj max in N. Velocity vi in m/s. Point P. Initial curve Fi = f (si, Fvj + Fj max) to 6.1 and appropriate deflection sj in millimeters. Spring characterist
36、ic Fi = f (si, Fvj + Fj max) to 5.3.1.2 and appropriate deflection sj in millimeters. 5.3.2.3 The individual values of the following, rounded to one decimal place. Height h0i in millimeters (mm). Deflection sfi in millimeters (mm). Spring rate ci in newton millimeters (N/mm). 5.3.2.4 Any specific ob
37、servations 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 propose to address all the safety problems associated with its use. It is the responsibility of the user o
38、f this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 7 Notes 7.1 Glossary. Bi-axial Stressing: Bi-axial stressing is the condition in which the elastomeric component is simultaneously stressed by forces F applied
39、 along two axes. Deflection s: The deflection s is 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 deflection sf describes the change in position of t
40、he force application point which occurs between the start of the 1st and the end of the 3rd stress cycle, due to the flow characteristics of the elastomeric component. For this purpose, the three (3) stress cycles shall be in direct sequence. Deflection sv: The deflection sv is that deflection cover
41、ed 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 universal testing machine taken as a point,
42、 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 force to which the elastomeric component t
43、o be tested is subjected. Its value and direction of application are determined by the installation conditions of the elastomeric component. Force Fmax: The force Fmax is the maximum value of force F to which the elastomeric component is stressed in addition to the initial force Fv. Height h0: The h
44、eight h0 is a dimension in the direction of application of force F, which shall be determined on the unstressed elastomeric component prior to the test. Initial Curve: The initial curve is the spring characteristic of the first stress cycle obtained during application on the elastomeric component fr
45、om F = Fv to F = Fv + Fmax. 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 direction of the force F and is approximately 1% to 2% of the force Fmax. Copy
46、right 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 GMW14683 Copyright 2013 General Motors Company All Rights Reserved January 2013 Page 5 of 6 Spri
47、ng 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 value F = Fv + Fmax. Spring Rate C: The spring rate is the slope
48、 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 variables F or s, in conjunction with the spring characteristic Stress Cycle: The stress cycle is that proced
49、ure, 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 the direction of force application, alphabetical and numerical suffixes shall be used. Alphabetical suffixes shall be used to identify the type of measured var
