中文摘要：

以MQ1625门座起重机为研究对象,利用Ansys软件对起重机门架及转台人字架结构进行强度分析,并根据分析结果提出改进方案。研究表明：门座起重机处于额定载荷时,人字架顶部应变位移最大,最大应变位移为21.03 mm;门架结构圆筒部分的局部变形也较大。采用适当增加板厚、提高焊接工艺的方法对起重机结构进行改进,与修改之前相比,应力应变分布有了明显改善。

英文摘要：

With MQ1625 portal slewing crane as the study object, strength analysis is performed for the crane portal and turntable A-frame with the software Ansys, and an improvement scheme is put forward based on the analysis result. The study shows that： when a portal slewing crane is at rated load, the strain displacement on the top of A-frame is maximal, with the maximum strain displacement being 21.03 mm; the local deformation at the cylinder part of the portal structure is relatively large. The crane structure is optimized by properly increasing the panel thickness and improving the welding process. After the modification, the stress and strain distribution is largely improved.