基于非线性接触原理的吊耳安全性分析

Safety analysis of lifting lug based on nonlinear contact principle

利用现行规范《钢结构设计标准》(GB 50017—2017)对吊耳进行受力分析时,仅考虑荷载为单一竖直方向,而在工程实际中,吊钩与吊耳间是一种接触关系,荷载方向非单一竖直,呈典型的非线性力学关系,因而采用非线性接触理论对吊耳进行受力分析会更加准确。以一矮塔斜拉桥钢箱梁吊装施工为工程背景,针对该项目采用超长块段钢箱梁吊装的吊耳存在起吊重量大、受力复杂等安全评估问题,基于非线性接触原理,采用Midas Civil大型有限元软件对吊耳在非垂直受力工况下的力学特性进行分析,并与现行规范进行对比。研究表明,对吊耳采用非线性接触原理的有限元分析法可充分考虑吊耳的实际受力方向,比采用现行规范计算的主应力和剪应力都大,且符合工程实际的复杂工况下的受力形式,对类似工程具有借鉴意义。

When using the current Steel Structure Design Code(GB 50017—2017)to analyze the force of the lifting lug,only a single vertical direction of load is considered.In engineering practice,there is a contact relationship between the hook and the lifting lug,and the load direction is not a single vertical,instead it is a typical nonlinear mechanical relationship,so it will be more accurate to use the nonlinear contact theory to analyze the force of the lifting lug.Taking the steel girder hoisting construction of a cable-stayed bridge with a low tower as the engineering background,in view of the safety assessment problem of heavy lifting and complex force of the lifting lugs hoisted by the super-long section steel box girder,Midas Civil was used to analyze the mechanical properties of the lifting lug under non-vertical stress conditions which were compared with the current code method.The research shows that the finite element analysis method using the nonlinear contact principle for the lifting lug can fully consider the actual force direction of the lifting lug,which is larger than the principal stress and shear stress calculated by the standard method,and can analyze the complex engineering in line with the actual engineering.The form of force under these conditions has reference significance for similar projects.