【作者】 王文娜；

【导师】 王军；

【作者基本信息】 河北科技大学 ， 材料加工工程， 2010， 硕士

【摘要】 起重机械是现代化生产中必不可少的运输工具。目前国内的桥式起重机,其结构尺寸一般都较国外同型号同吨位产品大许多,产生材料浪费问题。其原因除材料上有差别外,主要是结构设计不同造成的,因此首先对桥式起重机主梁结构进行分析,并提出了优化设计方案,减少了材料浪费。起重机主梁作为焊接钢结构,在其制造过程中,焊接工艺占很大的比重。如果焊接工艺设计不适当,焊接残余变形有可能导致拱度不足,甚至引起下挠,这会严重影响起重机的安全运行,对人身和财产安全造成危害。为此,又对桥式起重机主梁结构的焊接过程进行研究,采用数值模拟分析了焊接工艺参数对起重机主梁挠度的影响。为实现以上目的,首先利用ANSYS软件,在桥式起重机起重量和跨度一定情况下,对箱型主梁进行结构分析,并采用其中的优化程序对主梁进行优化设计,以达到在满足强度、刚度的前提下耗材最少的目的,得出了主梁的最优化设计结果,重量减轻了27%,效果明显;然后采用热力耦合及生死单元技术,选取分段移动串热源模型,对L型钢板进行焊接模拟,并给予实验验证;在此基础上按优化后的主梁结构尺寸建立主梁模型,进行了主梁盖板和腹板的焊接模拟,分析了焊接顺序对主梁挠度的影响,并进行了理论计算比较,这对主梁腹板下料时的拱度预置有很好的指导意义。更多还原

【Abstract】 Lifting machinery is essential for modern production as means of transport. The domestic bridge cranes’structure sizes are generally larger than the foreign products with the same model and the same tonnage. In addition to the difference of materials, the structural differences in size are the main reason. To reduce material waste, the studies of girder’s structure analysis and optimal design are proposed.The girder of crane is a structure of welded steel, whose welding process accounts for a large proportion in manufacturing process. If welding process programming is unreasonable, welding residual strain may lead to inadequate camber, or even cause the deflection, which will affect the safe operation of cranes seriously, and lead to the personal and property safety hazard. So the welding process is studied and the effect of the welding parameters on the deflection of crane girder is analyzed by numerical simulation.In the condition of certain weight and span of bridge crane’s girder, ANSYS finite element analysis software for structural analysis and procedures to optimize the design of girder are adopted. In order to achieve the least consumables under the premise of meeting the strength and stiffness, a optimal design result is obtained. It is lightened by 27 percent; Then, the welding of L-plate is simulated by moving segmented heat source model and adopting coupled thermo-mechanical and life and death cell technology, which is verified through experimental study. According to the optimized size, the model of crane’s girder is established to simulated the welding of lap and web of girder. The affect of welding sequence on the deflection is analyzed and comparison of theoretical calculations is carried out, which is a valuable guide for the pre-camber when the web is cut.更多还原