The Fatigue Strength of Box Girders in Overhead Travelling Cranes
A series of large-scale tests on 46 welded box section girders was conducted to determine the jutigue strength of girders used in overhead travelling cranes. The girders were divided into four groups and were tested under dlflerent stress ranges with variable-amplitude or constant-amplitude loadings. The stress spectra for variable-amplitude loudings were based on the test results for eight cranes used in normal conditions and were modelled by program blocks with eight amplitudes. From the tests the following results were obtained:
- fatigue life curves
- the relationship between the fatigue life of variable-amplitude loading and the fatigue life of constant-amplitude loading
- the distribution of fatigue strength of crane girders
- crack lengths and crack growth rates
Professor J. Zai, J. Cao and A.J. Bell