1、WORLDWIDEENGINEERINGSTANDARDSTest Procedure GMW14774Test Method for Determining the Breaking Strength of Componentsmade from Compressed Fibrous Materials Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 1 of 31 ScopeNote: Nothing in this standard supercedes applicable laws and
2、 regulations.Note: In the event of conflict between the English and domestic language, the English language shall takeprecedence.1.1 Purpose. This standard shall be used to determine the breaking strength of molded components madefrom hardboard, wood fiberboard etc. when acted upon by an indenting f
3、orce.1.2 Foreword. Not applicable.1.3 Applicability. Not applicable.2 ReferencesNote: Only the latest approved standards are applicable unless otherwise specified.2.1 External Standards/Specifications.None2.2 GM Standards/Specifications.GMW30103 Resources3.1 Facilities.3.1.1 Calibration. The test fa
4、cilities and equipment shall be in good working order and shall have a validcalibration label.3.1.2 Alternatives. Alternative test facilities and equipment may also be used. However, all measuringvariables as specified in this standard shall be determined correctly with respect to their physical def
5、inition.3.1.3 Tensile test machine in accordance with GMW3010 capable of traversing at a speed of(10 1) mm/minute and equipped with a force-extension recorder. It shall be equipped with a compressioncage of sufficient size and capacity to accommodate the test piece and test indenter.3.2 Equipment.3.
6、2.1 A supporting frame such that the component (or section therefrom) may be adequately supported duringtesting and the support closely resembles “as assembled in vehicle“ conditions. The supporting frame shall beof such a size, that the outer contour of the component (or section therefrom) may be s
7、upported for(10 5) mm. More specific details of the supporting frame may be shown on the Engineering Drawing ormaterial specification.3.3 Indenter. The indenter shall have a (32 0.5) mm diameter hemispherical impact head.3.4 Saws for preparation of test pieces.3.3 Test Vehicle/Test Piece. The comple
8、te component shall be used as the test piece whenever possible.Where the size, configuration, etc. prevents this, the largest possible test piece shall be cut from thecomponent, taking care to avoid stressing of the test piece during preparation, and that test piece includes anytest area designated
9、by specification. For initial sample approval and arbitration purposes 3 test piecesminimum and for routine quality control 1 test piece minimum shall be tested.Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permi
10、tted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14774 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 2 of 33.4 Test Time. Not applicable.3.5 Test Required Information. Not applicable.3.6 Personnel/Skills. Not applicable.4 Procedure4.1 Preparation. Tes
11、ts shall be carried out on test pieces in the as received condition i.e. no specialpreconditioning.4.2 Conditions.4.2.1 Environmental Conditions. Unless otherwise specified the test shall be performed at (+23 5) C.4.2.2 Test Conditions. Deviations from the requirements of this standard shall have be
12、en agreed upon. Suchrequirements shall be specified on component drawings, test certificates, reports, etc.4.3 Instructions.4.3.1 The complete component, or section therefrom shall be assembled to the supporting frame, and placedin the test equipment ensuring that the indentor is in line with the re
13、quired area of test.4.3.2 The indenter shall be indented into the test piece at a rate of (10 1) mm/minute until the test piecefractures or otherwise yields.5 Data5.1 Calculations. Not applicable.5.2 Interpretation of Results. Record the maximum force attained in paragraph 4.3.2.5.3 Test Documentati
14、on.5.3.1 The breaking strength shall be reported as the arithmetic average of the measured individual values, oras the single individual value, in Newtons (N), rounded to the nearest Newton.6 SafetyThis standard may involve hazardous materials, operations, and equipment. This standard does not propo
15、se toaddress all the safety problems associated with its use. It is the responsibility of the user of this standard toestablish appropriate safety and health practices and determine the applicability of regulatory limitations priorto use.7 Notes7.1 Glossary.Breaking Strength: The breaking strength a
16、s determined by this test method shall be defined as the force,acting in compression through a standard indenter, necessary to rupture the component or section therefrom.7.2 Acronyms, Abbreviations, and Symbols. Not applicable.8 Coding SystemThis standard shall be referenced in other documents, draw
17、ings, etc., as follows:Test to GMW14774On drawings, material specifications etc., the minimum required breaking strength of components made fromcompressed fibrous materials, shall be indicated similar to the following example:Breaking Strength to GMW14774 - 20 N minimum.Copyright General Motors Comp
18、any Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14774 Copyright 2013 General Motors Company All Rights ReservedJune 2013 Page 3 of 39 Release and RevisionsThis standa
19、rd was originated in November 2005. It was first approved by Global Textile SSLT inDecember 2006. It was first published in July 2007.Issue Publication Date Description (Organization)1 JUL 2007 Initial publication.2 JUN 2013 5 year refresh update (Textile GSSLT)Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
