基于焊缝影响的地下铲运机工作机构强度和动力学分析

发布时间：2018-05-03 06:15

本文选题：地下铲运机 + 正转六连杆工作机构　；参考：《山东理工大学》2017年硕士论文

【摘要】：地下铲运机是地下矿山无轨采掘作业必备的主体设备之一,依靠工作机构的运动来完成物料的装、运、卸。目前,工作机构均采用了焊接结构,焊缝的结构形式、焊接质量都直接影响着工作机构的强度。本文以2m3地下铲运机的工作机构为例,基于不同焊接形式、质量,对正转六连杆机构进行强度和动力学研究分析,以获得正转六杆机构工作状态下的强度分布规律及动力学特性。论文的主要工作如下:(1)研究了正转六连杆工作机构在插入和铲取工况下的受力状况,获得了两种典型工况下的机构强度理论计算方法;对动臂焊接结构的强度进行理论分析,得出焊缝的几何形状对焊接结构的强度存在极大影响,为进行强度有限元分析选择更加合理的焊接结构奠定了基础。(2)通过SolidWorks软件的参数化零件建模和虚拟装配技术,建立了2m3地下铲运机工作机构的虚拟样机。将其导入动力学仿真软件ADAMS中,选取两个典型的载荷分布——正载和偏载,对正转六连杆工作机构进行多刚体动力学仿真,获得了动臂上的三个主要铰接点的运动特性并得出最大受力的状态处在铲取位置,为更加合理地进行强度分析提供了依据。(3)在ANSYS Workbench中建立处于铲取工况下的工作机构有限元模型,添加正载和偏载载荷并进行静力学分析,找出了工作机构各构件的应力集中处和最大应力值,分析危险截面和高应力区的分布情况。由仿真结果可知,在两种不同的载荷情况下,动臂和摇臂的总体应力变化不大,且最大应力值均小于选择材料的许用应力。在偏载载荷下,由于正转六连杆机构的特性,连杆所受拉应力比正载载荷下明显增大了一倍。同时,铲斗斗刃与动臂侧板与横梁之间的焊接焊缝出现了应力集中情况,为进行焊接结构的强度仿真提供了依据。(4)对具有不同焊接形式的侧板与横梁之间的焊缝的动臂模型进行有限元仿真与研究,得出各因素对焊缝强度的一般影响规律,提出了更加合理的抗疲劳性能的焊缝结构形式。给出侧板坡口角度为40°、角焊缝加强高尺寸不超过8mm、所形成的焊缝表面为内凹形的焊接结构更能满足强度要求。
[Abstract]:Underground scraper is one of the main equipment necessary for underground mine trackless mining. It depends on the movement of working mechanism to complete the loading, transporting and unloading of materials. At present, the welding structure is adopted in the working mechanism, and the structure form and welding quality of the weld directly affect the strength of the working mechanism. In this paper, the working mechanism of 2m3 underground scraper is taken as an example. Based on the different welding forms and quality, the strength and dynamics of the forward rotating six-bar mechanism are studied and analyzed. In order to obtain the strength distribution and dynamic characteristics of the positive rotating six-bar mechanism. The main work of this paper is as follows: (1) the force condition of the forward rotating six-bar working mechanism under the conditions of insertion and shovel is studied, and the theoretical calculation method of the mechanism strength under two typical working conditions is obtained, and the strength of the welded structure of the arm is analyzed theoretically. It is concluded that the geometry of weld seam has a great influence on the strength of welded structure, which lays a foundation for selecting a more reasonable welding structure by means of finite element analysis of strength. (2) Parametric part modeling and virtual assembly technology based on SolidWorks software. The virtual prototype of working mechanism of 2m3 underground scraper is established. It is introduced into the dynamic simulation software ADAMS, and two typical load distributions, positive load and partial load, are selected to simulate the multi-rigid-body dynamics of the forward rotating six-bar mechanism. The motion characteristics of the three main hinge points on the arm are obtained and the state of the maximum force is in the shovel position. In order to make strength analysis more reasonable, the finite element model of working mechanism under the condition of shovel is established in ANSYS Workbench. The positive load and partial load are added and statics analysis is carried out. The stress concentration and the maximum stress value of each component of the working mechanism are found, and the distribution of the dangerous section and the high stress region is analyzed. The simulation results show that under two different loads, the total stress of the arm and rocker arm has little change, and the maximum stress value is smaller than the allowable stress of the selected material. Due to the characteristics of the positive rotating six-bar linkage, the tensile stress of the connecting rod is increased by twice as much as that under the positive load load. At the same time, the stress concentration appears in the welding weld between the bucket blade and the side plate of the moving arm and the beam. For the strength simulation of welding structure, the finite element simulation and research of the welding arm model between side plate and beam with different welding forms are carried out, and the general influence law of each factor on weld strength is obtained. A more reasonable weld structure with fatigue resistance is proposed. The groove angle of the side plate is 40 掳, the high size of the fillet weld is not more than 8 mm, and the welding structure with the inner concave surface is more suitable for the strength requirement.
【学位授予单位】：山东理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TD421

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