钢梁承载潜力的自适应分析  

Shakedown Analysis on the Potential of the Bearing Capacity of Steel Griders

作　　者：原海燕[1] 阎贵平[1] 刘磊[1] 

机构地区：[1]北京交通大学土木建筑工程学院,北京100044

出　　处：《中国铁道科学》2007年第6期60-64,共5页China Railway Science

摘　　要：自适应分析研究超出弹性极限的重复载荷作用下结构的弹塑性行为。与其他塑性理论相比,自适应理论的分析结果更逼近结构塑性破坏的实质。以日本某桥为例,以增量分析法为基础编制有限元程序,采用Timoshenko弹塑性分层梁单元模拟连续实腹钢梁桥结构,进行其在重复载荷作用下自适应行为分析。结果表明:随活载系数的增加,结构依次经历全弹性承载、自适应和塑性增量破坏3个阶段;按自适应理论分析,该梁能够承受的最大活载是设计活载的2.804倍;可见,对于按容许应力法设计的旧有钢桥,自适应分析能极大地挖掘其承载潜力。Shakedown analysis is a method which can be used to research the elasto-plastic behavior of a structure under variable repeated loads that exceed the structure＇s elastic limit load. Compared with other plastic theories, the analytical result of shakedown theory is much closer to the essential of a structure＇s plastic collapse. Taking a bridge in Japan as an example, a nonlinear finite element analytical program which based on incremental analysis method is established. In the program, the Timoshenko elasto-plastic layered-beam element is used to simulate a continuous steel solid-web girder bridge. The program then is used to analyze the shakedown behavior of the example bridge under repeated loads. The results indicate that with the increasing of the live load coefficient, the bridge experienced three stages in turn： elastic stage, shakedown stage and increment collapse. Analyzed with shakedown theory, the ultimate carrying capacity of the bridge is 2. 804 times than which is designed. So, to those old steel bridges which are designed with the allowable stress method, the shakedown analysis can dig its potential bearing capacity greatly.

关 键 词：自适应分析 连续钢梁桥 非线性有限元 Timoshenko分层梁单元 

分 类 号：U448.36[建筑科学—桥梁与隧道工程]