《GMW-14683-2007.pdf》由会员分享，可在线阅读，更多相关《GMW-14683-2007.pdf（5页珍藏版）》请在三一文库上搜索。
1、 WORLDWIDE ENGINEERING STANDARDS Test Method Materials GMW14683 Force-Deflection Characteristics of Elastomeric Components Under Bi-axial Stress Copyright 2007 General Motors Corporation All Rights Reserved November 2007 Originating Department: North American Engineering Standards Page 1 of 5 1 Scop
2、e 1.1 Determination of spring characteristic of elastomeric components. The test, according to this test method, provides information on the visco- elastic behavior of the elastomers used. 1.2 Determination of stressability of the elastomeric components in the installation position in vehicles and i
3、n accordance with the installation conditions. Note: Nothing in this standard supersedes applicable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 2 References Note: Only the latest approved standards are ap
4、plicable unless otherwise specified. 2.1 External Standards/Specifications. DIN 862 DIN 51220 DIN 876 ISO 7500-1 DIN 878 ISO 9513 DIN 6370 2.2 GM Standards/Specifications. GMW14734 3 Test Equipment 3.1 Calibration. The test facilities and equipment shall be in good working order and shall have a val
5、id calibration label. 3.2 Universal Testing Machine. For stressing of elastomeric components up to 50 kN maximum with constant velocity v (maximum deviation 10%), short form in text “Universal testing machine“. 3.2.1 Version According to: DIN 51220 ISO 7500-1 ISO 9513 3.2.1.1 Accuracy of: Force meas
6、urement: 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 case, correction of the measurement results
7、by the deformation of the testing machine is not necessary. 3.2.2 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 measurement results shall be performed. 3.2.3
8、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 the same testing and configuration parameters as
9、the component measurement. 3.2.3.1 The velocity vi shall be selected according to the application. The correction measurement shall cover the entire evaluation area. 3.2.3.2 The “rigid substitute body” is defined as the outer contour of the elastomeric component pressed into the corresponding compon
10、ent mount, according to the relevant component drawing, with an inserted pin. 3.2.3.3 The pin shall be tightened to the specified torque according to the elastomeric component drawing. 3.3 A test device for applying an additional constant force Fj to the elastomeric component hereafter referred to a
11、s the “test device“. 3.3.1 A test device which enables a stress to be gradually applied to the elastomeric component, up to a force Fj = Fvj + Fj maximum at a constant velocity of (1.25 0.10) x 10-3 m s-1, and subsequently maintains this force at a constant value. The moment at which the force reach
12、es its maximum value shall be indicated by the test GMW14683 GM WORLDWIDE ENGINEERING STANDARDS Copyright 2007 General Motors Corporation All Rights Reserved Page 2 of 5 November 2007 device. The test device shall span a range of force from 50 to 4000 N with an accuracy of 10 N. 3.3.1.2 Test devices
13、 which apply the force by means of suitable masses, such as lever systems, are preferred. 3.4 Workbench with machine vice 160 DIN 6370. 3.5 Measuring plate according to DIN 876 made of cast iron, 400 x 400 mm. 3.6 Testing and clamping devices for installing and fastening the elastomeric components o
14、n the universal testing machine. Roller tables and roller or ball straight-line mechanisms for forces up to 10 kN. 3.7 Stop watch or clock with a display range of 600 s and a reading accuracy of 0.1 s. 3.8 Dimensional Measuring Equipment. 3.8.1 Dimensional change measuring instrument, e.g., dial gau
15、ge 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. 3.8.2 Dimensional measuring instrument, e.g., caliper gauge according to DIN 862. 3.8.3 Dimensional measuring instrument, e.g., high-accuracy marking ga
16、uge with fine adjustment of the slider, vernier 0.1 mm, marking height 500 mm maximum. 4 Test Material 4.1 Test Sample Form. Test samples are elastomeric components (elastomeric components or elastomeric/metal components), which are used as components in vehicles. 4.2 Number of Test Samples. At leas
17、t three test samples shall be tested. 5 Test Method Deviations from this standard particularly deviations from the test sample pre-treatment, the technical data of the testing equipment, the stressing times and the test temperatures shall have been agreed upon. Such requirements shall be specified o
18、n the part drawings etc. and in test certificates, reports and similar. 5.1 Summary of Test Method. Testing of the deformation of elastomeric components for vehicles (elastomeric components or elastomeric/metal components) with constant velocity at + 23 5C. 5.2 Test Sample Preparation. For initial s
19、ampling 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 5C. 5.3 Test Procedure. 5.3.1
20、 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 as in accordance with the relevant test procedure. Between two tests on the
21、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 and test device, if this has an influence on the force display or the forces Fi and Fj. 5.3.2 Determina
22、tion of Height h0i. The height h0i shall be measured according to GMW14734 at + 23 5C, if this value is required for the elastomeric component. 5.3.3 Test Procedure. The test sample shall be stressed with Fj = Fvj at a velocity of (1.25 0.10) x 10-3 m/s, the dimensional change measuring equipment sh
23、all be set to zero (sj = 0), and the stress shall be reduced with an equal speed to zero Fj = 0. This cycle shall be repeated until the deflection change under stress Fvj is 0.01 mm (normally three cycles will be sufficient). The zero point of the dimensional change measuring equipment is then fixed
24、. 5.3.4 Increase the force, applied to the elastomeric component under test, at a velocity of (1.25 0.10) x 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,
25、applied to the elastomeric component, is maintained at a constant value during the remainder of the test. 5.3.5 The test sample shall be stressed 600 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
26、 to si = 0, then proceed according to diagram in Appendix A, Figure A1. 5.3.6 Stress the test sample with 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 sha
27、ll be determined. 5.3.7 Repeat the stress cycle according to 5.3.5, three (3) times. -,-,- GM WORLDWIDE ENGINEERING STANDARDS GMW14683 Copyright 2007 General Motors Corporation All Rights Reserved November 2007 Page 3 of 5 6 Evaluation and Rating 6.1 Record the initial curve Fi = f (si, Fvj + Fj max
28、) on the force-deflection characteristic. 6.2 Record the spring characteristic Fi = f (si, Fvj + Fj max) on the same force-deflection characteristic of Fi = Fvi to Fi = Fvi + Fi max during the fourth stress cycle and also determine the deflection sfi. 6.3 Determination of the spring rate ci at the p
29、oint P of the spring characteristic (6.2). Note: For tolerance specifications, the spring characteristic Fi = f (si, Fvj + Fj max) and the deflection sfi according to 6.2, as well as the spring rate ci according to 6.3 and the height h0i shall be used. The tolerance range zero point for the spring c
30、haracteristic Fi = f (si, Fvj + Fj max) can be moved along the abscissa of the force-deflection characteristic via the deflection sfi max. 7 Report 7.1 With reference to this standard, the test report shall also include the following: 7.2 Part name, part number or drawing number, test specification
31、number, additional identification, grade of elastomer, manufacturer, date of manufacture, date of test, test sample serial number. 7.3 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
32、 + Fj max) to 6.1 and appropriate deflection sj in mm. Spring characteristic Fi = f (si, Fvj + Fj max) to paragraph 6.2 and appropriate deflection sj in mm. 7.4 The individual values of the following, rounded to one decimal place: Height h0i in mm Deflection sfi in mm Spring rate ci in N/mm 7.5 Any
33、specific observations on the test sample (e.g., crushing folds, cracks, or other surface changes). 8 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
34、 the user of the standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 9 Notes 9.1 Glossary. Bi-axial Stressing: Bi-axial stressing is the condition in which the elastomeric component is simultaneously stressed by forces
35、 F applied 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 pos
36、ition of the 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 stress cycles shall be in direct sequence. Deflection sv: The deflection sv is that deflection
37、 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 universal testing machine taken as a
38、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 force to which the elastomeric compone
39、nt to 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:
40、The height 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 compone
41、nt from F = Fv to F = Fv + Fmax. GMW14683 GM WORLDWIDE ENGINEERING STANDARDS Copyright 2007 General Motors Corporation All Rights Reserved Page 4 of 5 November 2007 Velocity v: The velocity v is the constant velocity, with which the force application point moves in the direction of application of fo
42、rce F. 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 (1.2) % of the force Fmax. 9.2 Acronyms, Abbreviations, and Symbols
43、. Not applicable. 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 value F = Fv + Fmax. 10 Coding System Thi
44、s standard shall be referenced in other documents, drawings, etc., as follows: “Force-deflection Characteristic to GMW14683, Initial Curve F1 = f (s1, Fv2 + F2 max) etc.” 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 cha
45、racteristic. The spring rate c is determined by the relationship Fv1 =N F1 max =N v1 =.m/s s F c = Fv2 =.N F2 max =.N and the point P, by one of the two variables F or s, in conjunction with the spring characteristic. Force-deflection Characteristic = Designation GMW14683 = Test Method Stress Cycle:
46、 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. Initial Curve F1 = f (s1, Fv2 + F2 max) = Test Conditions and Requirements. 11 Release and Revisions Su
47、ffixes: For identification of the measured variables and the direction of force application, alphabetical and numerical suffixes shall be used. 11.1 Release. This standard originated in October 2005. It was first approved by the Global Elastomers Team in December 2006. It was first published in Nove
48、mber 2007. Alphabetical suffixes shall be used to identify the type of measured variable, e.g. It supersedes all regional test method specifications for Force-Deflection Characteristics of Elastomeric Components under Bi-axial Stress for use on Global Engineered materials including but not limited t
49、o GME 60233. H0 = Height of the unstressed elastomeric component: Fv = Initial force Numerical suffixes shall be used to identify the direction of application of a force, generally designated as i and j. i and j can adopt the values (1, 2, 3.n). The numerical suffix follows the alphabetical suffix, e.g. h01, Fv1 and Fv2, F1 max and F2 max GM WORLDWIDE ENGINEERING STANDARDS GMW14683 Copyright 2007 General Motors Corpo