按弹塑性本构关系的球墨铸铁井盖强度分析与设计

Strength Analysis and Design of Ductile Cast Iron Manhole Covers based on Elastoplastic Constitutive Relation

球墨铸铁井盖强度设计,其材质如果按全弹性材质考虑,太保守、浪费材料。本文从弹塑性介质理论出发,依据棒状试件的拉伸曲线,结合材料截面特点,通过分段积分法,求出最大许用弯矩校核强度来设计球墨铸铁井盖。破坏性压力测试实验表明,该方法从理论上符合棒状试件拉伸规律,从实践上符合井盖打压要求,是球墨铸铁井盖强度设计切实可行的方法。

A strength design of manhole covers based on perfect elasticity theory is usually too conservative and wasteful in materials. In this paper, a manhole cover of ductile cast iron was designed and the strength was checked based on elastoplastic theory by segmentation integration to calculate the maximum permissible bending moment combining with the tensile curves of the test bars and cross-section characteristics of the material. Experimental results show that this method is feasible and effective. The design are up to the manhole covers require and the way is a feasible for the strength design of ductile cast iron manhole covers.