【作者】 周强；

【导师】 杨文兵；

【作者基本信息】 华中科技大学 ， 工程力学， 2005， 硕士

【摘要】 斜拉桥是现代桥梁中的一种重要形式,其优点不一而足。从力学的角度来看,斜拉桥是一种由索塔、主梁、拉索组成的超静定结构,在其施工过程中,拉索的索力调整是调整桥梁结构受力状态的主要手段。目前,有很多研究从理论上证明可以找到适当的拉索初始拉力初始值以避免复杂的索力调整,甚至完全不需要索力调整,但是从近年来的工程实践中看,这些理论尚不能精确确定拉索的初始拉力,索力调整依然是桥梁工程中不可或缺的一环。在桥梁结构的有限元分析软件中,需要考虑拉索垂度效应等非线性因素,从而准确地模拟索力调整的过程。为了与施工无应力状态法配合,需要在计算结果中提供拉索的无应力索长。在基于ANSYS 的桥梁有限元分析软件的开发时,由于ANSYS 接口能力所限,开发人员很难如同编制自行开发的有限元程序那样,通过直接控制参量的数值来实现索力调整这一过程。所以,要在ANSYS 中实现索力调整的模拟,必须通过等效的方法。本文利用多段直杆法建立斜拉桥拉索模型,以模拟拉索的垂度效应; 利用温度的变化模拟应变变化,以模拟拉索张拉; 利用悬链线公式计算拉索的无应力索长,从而为索力调整在ANSYS 中实现提供了算法依据。在此基础上,本文使用了C++,FORTRAN 等工具,编制了相关程序,实现了索力调整的算法流程和施工模拟过程的数据组织过程,通过ANSYS 的接口与ANSYS 核心求解器联系起来,在ANSYS 中实现了索力调整,并完成了基于ANSYS的桥梁有限元分析软件的施工模拟模块之一部。更多还原

【Abstract】 Having many advantages, cable-stayed bridge is an important form of modern bridges. Cable-stayed bridge is a kind of statically indeterminate structure in the domain of mechanics. Tensing stayed cables is a chief method to controlling the mechanical behaviors of cable-stayed bridge. As proved, the initial tension force of stayed cable cannot be exactly calculated, which is to avoid the complex process of stayed cable’s tension. So, the tension adjustment of stayed cable is still the key process of bridges’construction. Nonlinear characteristics, including slack effect, should be taken into consideration in bridge FEA software. The unstressed length of cable, which is consulted by unstressed status controlling in the construction of bridge, is a part of results. Changing the temperature of stayed cable can exactly simulate the alteration in cables’tension. The slack of cable is under consideration by using multiple tension-only elements. The unstressed length of stayed cable can be also calculated by the theory of catenaries. All these equivalences are the foundations that simulate tensing stayed cables in ANSYS. Supported by these equivalences, some programs are to present the process of tensing the stayed cables and organization of data in the simulation of bridge construction. Linked to the ANSYS, these programs have been the very one part of bridge construction simulation in bridge FEA software.更多还原