σ_(max)/σ_m≠const时起重机零件的疲劳强度计算

Fatigue resistance calculation for crane parts at σ_(max)/σ_m≠Const

对于起重机零件的疲劳强度计算,起重机设计规范已对简单加载情况下,即σ_(max)/σ_m=const、γ=σ_(min)/σ_(max)=const应力状态的算式作出了规定,但起重机零件颇多处于复杂加载情况下,即σ_(max)/σ_m(?)const,而σ_m=const或σ_(min)=const的应力状态,对此亦应有相应的疲劳强度计算式。本文列出这些算式,并指出与简单加载情况算式的差别。

For crane parts fatigue resistance calculation, formulae are given for simple loading case, i. e. under stress state of σ_(max)/σ_m=Const. and γ=σ_(min)/σ_(max)=Const, in Crane Design Guidelines. However, many crane parts are complicatedly loaded, i. e. under stress state of σ_(max)/σ_m≠Const, but σ_m=Const or σ_(min)=Const, there must be corresponding formulae for fatigue resistance calculation. This paper introduces these formulae and points out their difference from those under simple loading conditions.