1、 WORLDWIDE ENGINEERING STANDARDS Test Procedure GMW14381 Exhaust-System Hanger Durability Test Copyright 2011 General Motors Company All Rights Reserved July 2011 Originating Department: GME Specification Center Page 1 of 5 1 Scope Note: Nothing in this standard supercedes applicable laws and regula
2、tions. Note: In the event of conflict between the English and domestic language, the English language shall take precedence. 1.1 Purpose. Determination of the hanger dynamic strength in a bench test. 1.2 Foreword. Not applicable. 1.3 Applicability. For all vehicle and exhaust-system hanger attachmen
3、ts. 2 References Note: Only the latest approved standards are applicable unless otherwise specified. 2.1 External Standards/Specifications. None 2.2 GM Standards/Specifications. None 2.3 Additional References. CTS/drawing specification 3 Resources 3.1 Facilities. Oscillating or hydropulse unit with
4、closed loop force control and cycle counter. The test device shall be suitable for dynamic forces of (100 to 500) N with regard to a test frequency range of (10 to 20) Hz (sine). The test facility shall have a valid ISO certificate which is noted in a test report. 3.2 Equipment. 3.2.1 Peak Value Rec
5、order. To automatically record the force/travel amplitude, with automatic shut-off for the testing machine when the force-/travel amplitude exceeds the adjusted limiting values. 3.2.2 Test Piece Mounting and Force Application. The test piece shall be mounted such that the suspension fastening/connec
6、tion is not impaired (see Figure 1 as an example). The force application shall ensure the malleability of the suspension. A link of 150 mm with a U-joint at both ends shall be installed between load cell and force application. Copyright General Motors Company Provided by IHS under license with Gener
7、al Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14381 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 2 of 5 Figure 1: Test Piece Mounting and Force Application 3.3 Test Vehicle/Test Pi
8、ece. At least 5 new production parts shall be tested. The suspension parts shall be produced as specified in the assembly drawing. 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 Set-up. The t
9、est set-up shall be performed using the direction of force application determined from the strain collectives for the respective vehicle type and engine, which is indicated in the CTS/drawing specification. 4.2 Conditions. 4.2.1 Environmental Conditions. The test shall be performed at (+23 5) C. 4.2
10、.2 Test Conditions. Deviations from the requirements of this standard shall have been agreed upon. Such requirements shall be specified on component drawings, test certificates, reports, etc. 4.3 Instructions. The strength test shall be performed as a single-step test. 4.3.1 Test force, test frequen
11、cy, test direction, cycles of failure (N 90%), and maximum permissible dispersion (N 90% / N 10%) shall be taken from the CTS/drawing specification. F = Fm (FT + FP) = Test force at load cell FP = Test force at test piece. Shall be taken from CTS/drawing specification. Copyright General Motors Compa
12、ny Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14381 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 3 of 5 FT = Inertia force of force appli
13、cation measured from load cell connection. The dynamic influence of the test device mass shall be taken into account for the test. Fm = static preload which shall be taken from CTS/drawing specification. 4.3.2 At least 5 parts shall be tested for each type to allow a statistical evaluation according
14、 to the logarithmic normal distribution. 4.3.3 Shut-off criterion for the test is the increase of the oscillation amplitude or the test frequency which automatically shuts off the testing machine as soon as the adjusted limiting values are exceeded. 4.3.4 The limiting values shall be 110 % maximum o
15、f the actual values measured at the beginning of the test. 4.3.5 If no first visible cracks occur, the test may be stopped at N 10%-value as specified by CTS/drawing specification. 4.3.6 A test protocol according to Appendix A shall be used for recording of test data and results and shall be added t
16、o a test report after the test. 5 Data 5.1 Calculations. In order to obtain reliable results for the number of cycles to first visible cracks/fracture determined in the endurance strength range in comparison to the N 90% value required on CTS/drawing specification, it is necessary to evaluate them a
17、ccording to the statistical method of fatigue life probability to the logarithmic normal distribution. N 50%-value: N 50% = Xm N 10%-value: N 10% = N 50% 101.28 log S N 90%-value: N 90% = N 50% / 101.28 log S Period spread: Period spread = P90% / P10% Calculation of probabilities shall be performed
18、according to the following formulas, where no uncracked test pieces or outliers shall be included. 5.1.1 Mean Value. Xm = 10 dP m e gl h n = number of values Xi = crack period 5.1.2 Standard Deviation. S = 10 1n-1 (log Xi log Xm)25.2 Interpretation of Results. The results determined shall be compare
19、d with the component drawing and evaluated accordingly. 5.3 Test Documentation. The test results shall be added to a test report as specified in paragraph 5.3.1 through 5.3.4 and paragraph 5.1. 5.3.1 Test Piece Description. Part name and number, development state, date of manufacture, drawing number
20、, drawing date. 5.3.2 Summary of Test Results and Evaluation. Briefly evaluation of test results (OK, NOK), test specification and if required deviations, comparison of results with CTS/drawing specifications. 5.3.3 Test Description. Description of test bench with photograph, brief description, desc
21、ription of used test set-up, calibration of testing equipment, initial cracking criterion and detection, load cell, force application mass measured from load cell connection, ISO certificate of test facility. Copyright General Motors Company Provided by IHS under license with General Motors CompanyN
22、ot for ResaleNo reproduction or networking permitted without license from IHS-,-,-GM WORLDWIDE ENGINEERING STANDARDS GMW14381 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 4 of 5 5.3.4 Documentation of Individual Results. Test load, travel amplitude of test cylinder, test
23、direction, test frequency, number of cycles for initial cracks, position and photograph of initial cracks, logarithmic characteristic data. 6 Safety This standard may involve hazardous materials, operations, and equipment. This standard does not propose to address all the safety problems associated
24、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. 7 Notes 7.1 Glossary. Not applicable. 7.2 Acronyms, Abbreviations, and Symbols. Not applicable. 8 Coding Sy
25、stem This standard shall be referenced in other documents, drawings, etc., as follows: Test to GMW14381 9 Release and Revisions This standard was originated in October 2005. It was first approved by Global Exhaust SSLT in November 2005. It was first published in November 2005. Issue Publication Date
26、 Description (Organization) 1 NOV 2005 Initial publication. 2 JUL 2011 5 year refresh; transfer to new template. 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 E
27、NGINEERING STANDARDS GMW14381 Copyright 2011 General Motors Company All Rights Reserved July 2011 Page 5 of 5 Appendix A A1 Test Protocol Muffler Component Order: Test specification: Part name: Test Building: Part No.: Test Facility: Drawing No.: Load Cell: Supplier: Test Bench: FT = Inertia force a
28、t test device in kN FP = Test force at test piece in kN as per specification F = actual test force at load cell in kN F = (FT + FP) FT = m s (6.28 f)2 / 106 in kN x mT in kg x s in mm x f in 1/s mT =.kg FT =kN Shut-off for testing machine travel amplitude% Shut-off for testing machine frequency viol
29、ation.% Temperature conditioning after Force sensor calibrated on Test bench certificated on Test pieces marked Photograph test set-up Date Time Name Test No. Test torque Mb in Nm Test force F in N Lever arm X in mm Machine data in V Travel amplitude s in mm Test direction X/Y/Z Test side (Note 1) T
30、est frequency f in Hz Initial cracks N in cycles Position of initial cracks (Photograph No. position of initial cracks) Note 1: E = Input, A = Output, L = left, R = right Copyright General Motors Company Provided by IHS under license with General Motors CompanyNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-
