JB/T 12662-2016Internal combustion engines - Torsional fatigue test method for crankshafts (English PDF)

National Standard of the People's Republic of China

ICS

27.020

Issued by: Ministry of Industry and Information Technology of the People's Republic of China

Contents

• 1 Scope
• 2 Normative references
• 3 Terms and definitions
• 4 Test principle
• 4.1 Base number of cycles
• 4.2 Test criteria
• 4.3 Principle of the test method
• 4.4 Requirements on the test accuracy
• 5 Test conditions
• 6 Test device
• 6.1 General
• 6.2 Structure of the test device
• 6.3 Accuracy and verification of the instruments
• 7 Preparation of the specimens
• 7.1 Cutting of the specimens
• 7.2 Number of specimens
• 8 Test steps
• 8.1 Preparation of the specimen
• 8.2 Mounting of the specimen
• 8.3 Determination of the resonance frequency
• 8.4 Test calibration
• 8.5 Loading test
• 9 Processing of the test data
• 9.1 Comparison
• 9.2 Calculation of the other fatigue strengths
• 10 Original records
• 11 Test report
• Annex A (normative) Calculation of the safe fatigue strength
• Figure 1 Diagram of the torsional fatigue test device
• Figure 2 Diagram of the cutting positions of the specimen
• Figure 3 Diagram of the scribing positions of the specimen
• Figure 4 Positions of the strain gauges and wiring diagram
• Figure 5 Full bridge connection diagram of the strain gauges
• Table A.1 Relation between the minimum number of pairs and the coefficient of variation (confidence level of 95 percent or more, relative error of 5 percent or less)
• Table A.2 Relation between the minimum number of pairs and the correction value K
• Table A.3 Relation between the minimum number of pairs and the coefficient of variation (confidence level of 90 percent, relative error of 10 percent, survival rate of 99,9 percent)