梁格法在midas中的运用.pdf

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1、midasCivil2010梁桥专题—梁格IntegratedSolutionSystemforBridgeandCivilStrucutres目录°一、剪力-柔性梁格理论1.纵梁抗弯刚度·······································································32.横梁抗弯刚度·······································································43.纵梁、横梁抗弯刚度··································

2、·························44.虚拟边构件及横向构件刚度···············································5°二、单梁、梁格模型多支座反力与实体模型结果比较°三、采用梁格建模助手生成梁格模型1.前言·······················································································72.结构概况································································

3、···············73.梁格法建模助手建模过程及功能亮点·······························114.修改梁格··············································································225.在自重、偏载作用下与FEA实体模型结果比较················24°四、结合规范进行PSC设计midas梁桥专题—梁格梁格Civil2010一、剪力-柔性梁格理论1.纵梁抗弯刚度【强制移轴（上部结构中性轴）法】a.各纵梁中性轴与上部结构中性轴基本重合b.强制移

4、轴，使各纵梁中性轴与上部结构中性轴基本重合，等效纵梁抗弯刚度3midas梁桥专题—梁格梁格Civil20102.横向梁格抗弯刚度3.纵梁、横梁抗扭刚度4midas梁桥专题—梁格梁格Civil20104.虚拟边构件及横向构件刚度此处d’为顶板厚度。此处d为顶板厚度。5midas梁桥专题—梁格梁格Civil2010二、单梁、梁格模型多支座反力与实体模型结果比较比较结果：与实体模型结果相比较，可得出在自重荷载作用下，单梁模型计算的多支座反力结果失真，而梁格模型结果较合理。梁格模型（kN）150010005000梁格模型（kN）多支座梁格模型实体模型（kN）150010005000实

5、体模型（kN）多支座实体模型单梁模型（kN）15001000500单梁模型（kN）0支座1支座2支座3支座4支座5支座6多支座单梁模型6midas梁桥专题—梁格梁格Civil2010采用梁格建模助手生成梁格模型1.前言宽梁桥、斜交桥、曲线桥的单梁模型无法正确计算横向支座的反力、荷载的横向分布、斜交桥钝角处的反力以及内力集中效应，利用梁格法模型可以非常方便的解决以上问题。梁格法建模的关键在于采用合理的梁格划分方式和正确的等效梁格刚度。用等效梁格代替桥梁上部结构，将分散在板、梁每一区段内的弯曲刚度和抗扭刚度集中于最邻近的等效梁格内，实际结构的纵向刚度集中于纵向梁格构件内，横向刚度

6、集中于横向梁格内。理想的刚度等效原则是：当原型实际结构和对应的等效梁格承受相同的荷载时，两者的挠曲将是恒等的，并且每一梁格内的弯矩、剪力和扭矩等于该梁格所代表的实际结构部分的内力。由于实际结构和梁格体系在结构特性上的差异，这种等效只是近似的，但对一般的设计，梁格法的计算精度是足够的。梁格法作为桥梁空间分析的一种简化方法，虽然较比板壳、实体有限元方法建模简单、求解方便，但是前期的截面特性计算量大，且对于新手来讲容易出错，非常耗时。midasCivil的梁格法建模助手功能可以帮助用户轻松实现上述功能。梁格法建模助手，对于单箱多室箱梁桥、斜交桥、曲线梁桥可自动生成梁格模型。2.结构

7、概况本桥为29.97+30+29.97三跨预应力混凝土连续梁桥。主梁为单箱3室结构，梁宽21.2m，桥梁采用满堂施工、一次落架。通过本例题重点介绍midasCivil软件的梁格法建模助手功能以及结合规范进行设计。桥梁三维几何模型图7midas梁桥专题—梁格梁格Civil20102.1定义材料°模型>材料和截面特性>材料定义C50混凝土为了与FEA实体模型的自重结果作比较，将端横梁容重设为0.定义Strand1860钢材8midas梁桥专题—梁格梁格Civil20102.2定义截面定义Strand1860