超大型抓斗卸船机钢结构非线性动力响应仿真

【作者】 郑培；

【导师】 王悦民；

【作者基本信息】 上海海事大学 ， 机械设计及理论， 2004， 硕士

【摘要】 抓斗卸船机是目前世界上用于散货接卸港的主要机械设备，随着散货船大型化、巨型化的发展要求的抓斗卸船机也要向大型化发展。因此随着吊重越来越重，吊重的起升和小车的运行速度越来越快，起吊和卸货以及小车、大车的起制动所引起的动力响应越来越对起重机的结构起着重要影响。各有关标准在卸船机的钢结构设计过程中动力系数和起升载荷的选取的取法各不相同，但基本上对整个结构采用一个动力系数的方法，但大型卸船机整机结构的不同部件的动力系数的差别较大。而有关卸船机的钢结构的动力仿真现在越来越成为许多专业工程人员所关心的问题。 动力仿真技术已经非常广泛的应用于很多制造行业当中，然而在我国，这项工作才刚刚处于起步阶段。对于很多大型的港口装载机械的动力仿真问题研究较少，很多有关抓斗卸船机的研究都是通过对现场上测试的数据进行整理与分析。本文根据卸船机的实际工作过程，结合大型有限元软件ANSYS对卸船机工作循环过程进行仿真模拟，从中观察结构的动力响应规律。整个分析过程主要有以下五个过程。 1．根据卸船机的金属结构设计图纸确定卸船机各个部件几何尺寸以及具体位置，通过分析不同部件的截面尺寸以及重量计算其相应的截面性质和材料密度，以及不同的结构部件采用其相应的单元类型，从而建立抓斗卸船机作业时的载荷变化与运行的在ANSYS中数学模型。 2．根据卸船机工作循环中小车的行走过程将卸船机的大梁离散化，选取适当的时间间隔建立节点，通过这样来模拟小车在工作循环过程中随着时间的变化而分别作用在大梁不同的位置。在一个工作循环过程中当小车运行到大梁的某一个位置时，利用ANSYS中的瞬态动力学计算方法求解出此刻卸船机的结构动态响应。最后就可以得到小车在一个工作循环工程中结构上任意一点的动力响应。 3．卸船机在实际的运作过程中经常会遇见不同装载能力的货船，由于这些货船的船宽不相同，这样卸船机抓斗的起升位置也就不同。本文选取了三个可能产生结构动力响应比较大的位置进行仿真模拟。 4．卸船机结构优化后的动力响应。 5．将仿真模拟计算的数据和实际测量的数据进行对比，综合这两个方面的数据，得出动力响应系数在卸船机结构上不同部件、不同位置上的变化规律，为将来卸船机的钢结构设计提供相应的支持。更多还原

【Abstract】 Bulk unloader is mostly port machine to load and unload bulk cargo in the world. Bulk unloader will be developped to be large-scale, with ship being more enormous and larger. In another way, because the weight of grab and cargo is more and the speed of grab and cargo is faster, dynamical respond causing by start and brake of grab or trolley or grantry is weightily influence to unloader’s structure design. There are many kinds of criterion to choose the factor of dynamical respond during the design. At same time, it is not in accord with fact to choose only factor in the whole structure. We should calculate reasonable factor to insure safety according to different parts of whole structure. Many crane manufacturers will be more and more concerned about emulate of dynamical respond.The technic of emulate of dynamical respond has been applied to many industries. But in our country, this technic is to start stage. There are a little research on emulate of dynamical respond of port crane and some work is to study and analyse the data which be obtain by tested on unloader. We used finite element analysis software-ANSYS to simulate the unloader work cycle in according with practical work process in this paper. The whole course involve five parts as following.1. through anaslysing section real constant and weight of different parts and selecting different element type which are based on structure blueprint, we will build the ANSYS model.2. Unloader boom will be discrete based on trolly travelling on it. We will select propriety space of time to set up node, so we could simulate trolly travels different location on boom which change by time during the work circulate. When trolly travels some place, we can calculate structure dynamical respond on this spot wih transient anaslyse of ANSYS. After a circulate ends we will get any node of structure dynamical respond in this circulate.3. When we are loading and unloading ,we will meet all kinds of ship that have different capacity. There are different place where grab lift, because of difference of width of ship. We choose three loactons where grab arise to simulate trolly workcirculate and structure dynamical respond is distinct in those loactons.4. unlaoder’s structure dynamical respond having been optimized.5. We will contrast result by ANSYS simulating to the data which got on testing. Then we hope to obtain the rule which dynamical respond how to change in the different parts and locations during the trolly wok circulation.更多还原