1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14734 The Determination of the Force-Deflection Characteristics and Creep Properties of Elastomeric Components Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 1 of 6 1 Scope Note: Nothing in this standard supercedes appl
2、icable laws and regulations. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. The object of this test procedure is the determination of the deflection and creep shown by elastomeric components used in vehicles under a
3、constant force at a temperature of + 23 C 5 C. 1.1.1 The determination of the force-deflection and creep characteristics shown by elastomeric components. The data given by this test procedure will also enable an indication of the state of cure of the elastomer to be obtained. 1.1.2 The determination
4、 of the installed dimensions of the elastomeric components in the as-assembled condition. 1.2 Foreword. Not applicable. 1.3 Applicability. Not applicable. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. DIN 862 D
5、IN 876-2 DIN 878 2.2 GM Standards/Specifications. None 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 label. 3.1.2 Alternatives. Alternative test facilities and equipment may also be u
6、sed. However, all measuring variables as specified in this standard shall be determined correctly with respect to their physical definition. 3.2 Test Equipment. The test machine for applying a constant force to elastomeric components hereafter referred to as “test machine“, shall consist of a device
7、 which will allow a force to be gradually applied to the component up to a value of F = Fv + Fk, at a velocity (v) = 1.25 0.10 10-3 m/s, and shall also be capable of maintaining a constant force. The time of application of the full load shall be indicated. The force range of the test machine shall n
8、ormally be from 50 to 10 000 N, and the accuracy of force indication shall be 0.2 N minimum up to 500 N force, and 10 N above this. Test machines, which apply the force by means of suitable masses, with the use of lever systems if required, shall be preferred. 3.2.1 Dimensional Measuring Equipment.
9、Dimensional change measuring equipment, e.g., linear dial gauge to DIN 878, with a range of 0 mm to 10 mm, an accuracy of 0.01 mm and exerting a substantially constant force of s6000,i (e.g., s60000,i, s600000,i) shall be noted. The creep will normally be found to be a linear function of log time, a
10、nd this may be plotted as a check. The change of the ambient temperature during the test period should be measured and recorded. 4.3.2.7 Shortened Test. If, at 600 s it is found, that the creep is a linear function of log time, when checked from the values obtained at s6, s60 and s600, a shortened t
11、est may be performed as specified in Section 6. 5 Data 5.1 Calculations. Not applicable. 5.2 Interpretation of Results. Not applicable. 5.3 Test Documentation. 6 Evaluation and Rating If the shortened test method described in paragraph 4.3.2.7 is carried out, the values of s6000,i and installed heig
12、ht Hi shall be obtained by extrapolation as follows: Creep s6000,i Where: s6000,i = 23 (s600,i s6,i) Force-deflection, s6000,i Where: s6000,i = s6,I + s6000,i Installed height, Hi Where: Hi = h0i - s6000,i 7 Report In addition to reference being made to this test procedure, the test report shall als
13、o include the following data. Part name. Part number. Test specification number. Additional identifications. Manufacturer. Grade of elastomer. Date of manufacture. Date of test. Test sample number. Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for Resa
14、leNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARD GMW14734 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 4 of 6 The values of the following: Initial force Fvi (newtons) Force Fki (newtons) The individual values, th
15、e means of the individual values, and the range of the extreme values from the mean of the following, rounded to one decimal place. Height h0i (millimeters) Height hvi (millimeters (if required) Installed height, Hi (millimeters) And also the following, rounded to two (2) decimal places. Force-defle
16、ction s6, (millimeters) Creep s6000,i (millimeters) Any specific observations on the test sample, e.g., folds, cracks, and other surface defects. 8 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems assoc
17、iated 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. 9 Notes 9.1 Glossary. Creep s6000: The creep s6000 shall be the change in dimension of the elastomeri
18、c component which occurs between the 6th and 6000th s following application of the force F = Fv + Fk, measured in the direction of that force. Force-Deflection s6 (s60, s600, s6000,). Commencing from the height hv the force-deflection s6 (s60, s600, s6000) shall be the change in this dimension which
19、 occurs after the 6th s (60th, 600th, 6000th, s) following the application of the force F = Fv + Fk, in the direction of this force. Force F: The force F is the force, which shall be applied to the elastomeric component. Its magnitude and direction shall correspond with the installed conditions of t
20、he component. Force Fk: The force Fk shall be the major force applied to the elastomeric component in order to determine its force-deflection and creep properties. It acts in the direction of the force F. Height h0: The height h0 shall be a dimension in the direction of the force F. It shall be dete
21、rmined upon the unstressed elastomeric component prior to the application of any force. Height hv: The height hv shall be a dimension in the direction of the force F, determined under the initial force Fv acting on the elastomeric component. Initial Force Fv: The initial force Fv shall be the force,
22、 which is initially applied to the elastomeric component in order to establish a datum point for measurements. Its magnitude is normally 1% to 2% of force Fk and it acts in the direction of the force F. Installed Height H: The installed Height H shall be a dimension in the direction of the force F,
23、and is measured in the 6000th s after application of the force F = Fv + Fk on the elastomeric component. Numerical Subscripts: Generally used to identify the direction, in which a force is applied, and shall be generally designated i, i may take the form 1, 2, 3 to n. They shall be placed behind any
24、 other subscript used e.g., Fkl. Where two (2) numerical subscripts occur, they shall be separated by a comma, e.g., s6000,1. If there is only one (1) direction, in which a force is applied, the numerical subscript l can be excluded, e.g., s6000. Subscripts: To identify the force or dimension being
25、applied or determined and their directions, alphabetical and numerical subscripts shall be used. Alphabetical subscripts shall normally indicate the type of force or dimension. For example: H0 a dimension of the unstressed elastomeric component. Fv initial force applied. Copyright General Motors Com
26、pany Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARD GMW14734 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 5 of 6 Fk major force applied. In s
27、pecific instances, numerical subscripts are used to define certain values. For example: s6 (s60, s600, s6000,) which indicates the deflection of the elastomeric component after the 6th (60th, 600th, 6000th) s. 9.2 Acronyms, Abbreviations, and Symbols. v velocity 10 Coding System This standard shall
28、be referenced in other documents, drawings, etc., as follows: Test to GMW14734 11 Release and Revisions This standard was originated in October 2005. It was first approved by Global Components and Engine Mounts Team in December 2006. It was first published in December 2007. Issue Publication Date De
29、scription (Organization) 1 DEC 2007 Initial publication. 2 FEB 2013 2012 Revision. (Elastomers Global Subsystem Leadership Team) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-
30、,-GM WORLDWIDE ENGINEERING STANDARD GMW14734 Copyright 2013 General Motors Company All Rights Reserved February 2013 Page 6 of 6 Appendix A Fi = f (t), si = f (t) and v = f (t) of the sequence of the Force-deflection test. Also refer to 4.3.2 of this test procedure. Curve A: Force Time Diagram (Fi =
31、 f (t) Curve B: Displacement Time Diagram (si = f (t) Curve C: Velocity Time Diagram (vi = f (t) Figure A1: Schematic Sketch (only in principle, not scale) Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
