为改善传统索塔锚固区拉杆—压杆模型的精度,采用密度法对传统模型进行拓扑优化.将连续介质离散为若干有空穴的单元,设定拓扑优化方向(体积减小率)进行迭代,得到相对密度趋近于1的单元,即找到最有效的荷载传递单元和路径,从而获得精确的拉杆、压杆面积和角度.将该方法应用于索塔锚固区强度校核中,以迫龙沟特大桥为例进行说明.采用通用软件ABAQUS建立该桥上塔柱索塔锚固区节段模型,通过拓扑优化获得节段有效传力区域退化模型,求解模型中拉杆、压杆及节点强度,并采用AASHTO规范校核,结果表明杆件及节点强度均满足要求.%To improve the accuracy of the conventional strut-and-tie model applied to pylon anchorage zone,the density method was used to carry out the topology optimization of the model.In the method,the continuous medium was dispersed into several elements with cavity,the direction of the topology optimization (volume reduction ratio) was established for iteration and the element having the relative density approaching 1 was acquired,i.e.the most effective load transferring element and path were found and the accurate areas and angles of the struts and ties were therefore obtained.The method was then applied to the strength checking of the pylon anchorage zone and by way of example of the Polong Gully Bridge,the method was illustrated in specific details.By means of the universal software ABAQUS,the segment model of the anchorage zone in the upper column of the pylon of the bridge was set up,the degradation model of the effective load transferring areas of the segments of the anchorage zone was obtained,using the topology optimization method and the strength of the struts,ties and joints in the model was solved and was checked against the provisions in the AASHTO.The results of the checking proved that the strength of the members and joints could all satisfy the requirements.
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