ABSTRACT

This simple relationship between load and stress is not true if the same load is applied with a slight offset on the head of the bolt. Then a condition of combined tension and bending will result. Since bending greatly amplifies the stress, the slightest offset will produce a large difference in the local maximum tensile stress. This condition significantly affects sustained load time-to-failure test results as demonstrated in Appendix 1. That is why great care must be taken in conducting a tensile test, especially when subjecting notched round tensile bars or bolts in tandem to hydrogen embrittlement testing.