空间预应力钢束平滑建模及张拉过程模拟方法

A new method for smooth modeling and tension process simulation of spatial pre-stressed tendons

提出一种空间预应力钢束连续平滑模型的建立方法,以及提出考虑钢束与孔道之间摩擦、滑移等相互作用的张拉过程模拟方法。基于空间预应力钢束为一条柱面相贯线的本质特性,采用辅助实体相贯的方法建立其连续平滑模型;通过建立孔道实体并与主梁进行布尔运算,实现孔道轴线与钢束节点的一一对应;采用法向点-点接触单元模拟摩擦滑移;采用预紧单元模拟张拉。分析表明:辅助实体相贯法建立的连续平滑模型优于传统空间坐标合成法建立的空间折线模型;采用接触单元与预紧单元组合模拟张拉过程,可反映钢束节点与混凝土内部节点之间的摩擦、滑移等非线性效应,钢束呈整体受力状态,优于传统的初应变法。

A method for establishing continuously smooth model of spatial pre-stressed tendon(SPT),as well as the actual tension process simulation method considering the interactions between SPT and duct such as friction and sliding,etc.,is proposed.The continuously smooth geometric model of SPT is established by the proposed intersecting auxiliary body method based on its characteristics of cylinder intersecting line.The node corresponding relationship between tendon and duct is achieved by establishing the solid model of duct and perform Boolean operations with main girder.The frictional contact between tendon and duct is simulated by using node to node contact elements.The tension process is simulated by using pretension elements.A case study shows that the continuously smooth model of SPT established by the proposed intersecting auxiliary body method is better than the spatial polyline model established by the conventional composite coordinate method.The global mechanical behavior of SPT and the nonlinear effects such as friction and sliding,etc.between tendon node and internal concrete node can be embodied by using node to node contact elements combination with pretension elements,which is better than the conventional initial strain method.