异径弯管的无力矩经向应力解析解

Meridian membrane stress of bend reducer

根据异径弯管的结构特性,利用异径弯管的合力平衡条件推导了内压作用下无力矩异径弯管的经向应力式,该式与直管的经向应力式型式相同,只不过是弯管的截面半径含义略有区别。经过误差分析及薄壁异径弯管无力矩时的旋转薄壳法应力验证说明,把异径弯管非轴对称力学模型扩展成轴对称力学模型所得到的应力场,两者差异不大,且因为管内径ri<管中径r而使结果偏于安全。对于承受内压的异径弯管,经向应力的危险截面是异径弯管的小端口横截面,符合直管的特征。

Formula of meridian membrane stress of bend reducer has inferred by the condition of total force balance according to its structure character. It is same with the formula of tube in type but radio of across section is some different. After error analyze, it has proved that turn the un-axial-symmetric mechanics model of bend reducer into the axial-symmetric one is not much different, and so the result is intent to safe as inside radio (ri) is smaller than the middle radio (r). The dangerous section of meridian membrane stress of bend reducer under internal pressure is the section at large end, with the character of tube.