大型履带起重机起臂过程的动态性能研究

发布时间：2018-12-18 05:57

【摘要】：履带起重机具有起重量大、接地比压小、臂架有多种组合方式、可带载行驶等优点，广泛地应用于石油化工、风电、水利、铁路和桥梁建设等大型工程。随着国家经济建设的快速发展，越来越多的大规模设施建设工作需要完成，需要调运更大重量和体积的物品以及实现更高的起升高度。这样，大型履带起重机愈来愈体现出其在大吨位、大体积和大起升高度方面的优势，国内市场对大型履带起重机的需求量越来越大，促进履带起重机市场蓬勃发展。由于大型建设工程的蓬勃发展，履带起重机向大吨位和大起升高度方向发展成为一个必然的趋势。常采取延长臂架长度和增加主、副臂组合工况等方式来实现起重机更大的起升高度和作业范围，以及在大起升高度和工作幅度下的起重机的高性能。臂架组装完成后，臂头部分放置在地面上，而底节臂与转台连接铰点距地面较高，在臂架自重作用下，臂架会产生下挠，部分接地。起臂过程中，变幅钢丝绳收紧，给臂架轴向分力，加剧臂架下挠，产生二次变形。臂架越长，其非线性效果越明显，在二次变形下，臂架轴向力剧烈增加，易引起臂架结构失稳而导致起臂过程中臂架损坏。由于臂架长度越长，起臂过程越危险。本文以徐工建机某大型履带起重机的标准轻型臂、超起轻型臂和超起塔式副臂等组合方式的最长臂的起臂过程为计算工况，进行臂架静力学和起臂动力学分析计算。本文基于ANSYS有限元分析软件，选择相应的单元类型，，利用ANSYS特有的APDL语言进行臂架系统不同臂节的建模和整个臂架系统的组装工作。通过在各个臂节连接处的对称位置设置支撑杆的方法来模拟地面对臂架的支承。用LINK10单元模拟变幅拉板和变幅钢丝绳，利用其在温度载荷下的线性变形特性，通过设置相关的线性热膨胀系数和温度载荷，使单元长度匀速缩短，带动臂头，实现起臂控制。本文以温度载荷代替常规载荷，解决了起臂过程模拟中，由于拉板力大小和方向随时间不断变化，难以定义载荷步的问题。首先采用ANSYS软件的静力学计算模块进行臂架在各个仰角的静力学分析，提取危险截面处主弦杆在各个角度的轴向力并拟合成曲线。提取主弦杆轴向应力极值，并与其许用极限进行比较，确定计算起臂工况的安全程度，为后面的动力学分析作参考。 ANSYS结构动力学分析模块中含有瞬态分析模块，可对起臂过程进行动力学分析。通过设置不同的起臂时间进行起臂动力学分析，得到危险截面处主弦杆的轴向力时间历程曲线，轴向应力极值不超过许用极限作为起臂安全时间。并对起臂时间较长的工况进行起臂方式的优化，缩短起臂时间。最后，为验证本文计算方法的正确性，进行QUY70履带起重机标准主臂起臂工况测试。通过动态应变仪进行起臂过程中主弦杆上应变片的动态应变数据采样，将采集的应变曲线进行换算和处理，分别与有限元静力计算结果和动力学分析结果比较，验证本文算法的正确性。本文对大型履带起重机的起臂过程进行了动力学模拟，且提出了模拟臂架自重作用下部分接地的方法和温度载荷控制起臂的控制方法，为起臂过程的模拟控制提出了新的思路。并且通过实验验证了计算方法的正确性，本文计算结果可为实际的起重机设计及起臂过程调试提供参考。
[Abstract]:The crawler crane has the advantages of large lifting weight, small grounding ratio, multiple combination modes of the arm frame, carrying and running, and the like, and is widely applied to large-scale projects such as petrochemical, wind power, water conservancy, railway and bridge construction. With the rapid development of national economic construction, more and more large-scale facility construction work needs to be completed, and it is necessary to transfer more weight and volume of goods and to achieve a higher lifting height. In this way, the large-scale crawler crane is more and more important in the large-tonnage, large-volume and high-rise height, and the domestic market demand for the large-scale crawler crane is increasing, and the market of the crawler crane is promoted to flourish. Because of the vigorous development of the large-scale construction project, the crawler crane has become an inevitable trend to the large-tonnage and large-lift height direction Potential. It is often adopted to extend the length of the arm support and to increase the working conditions of the main and auxiliary arms, so as to realize the higher lifting height and operating range of the crane, as well as the high performance of the crane under the large lifting height and the working amplitude. can. After the arm support is assembled, the arm head part is placed on the ground, and the connecting hinge point of the bottom joint arm and the rotary table is higher than the ground, ground. In the process of starting the arm, the luffing wire rope is tightened, the axial force component of the arm support is increased, the lower deflection of the arm frame is increased, and the secondary change is generated. The longer the arm support, the more the non-linear effect, and under the secondary deformation, the axial force of the arm support is greatly increased, which is easy to cause the instability of the arm support structure and can lead to the damage of the arm support during the operation of the arm. Bad. As the length of the arm support is longer, the arm process The more dangerous it is. In this paper, the arm process of the most long arm of the standard light arm, the super-lifting light arm and the super-lifting tower type auxiliary arm of a large-scale crawler crane of the XU construction machine is taken as the calculation working condition, and the static and the lifting arm dynamics of the arm support are carried out. In this paper, based on the finite element analysis software of ANSYS, the corresponding unit type is selected, and the model of different arm sections of the arm support system and the whole arm support system are carried out by using the special APDL language of ANSYS. and the ground pair is simulated through the method of setting the supporting rod at the symmetrical position of the joint of each arm joint. The support of the arm support is simulated by using the LINK10 unit to simulate the luffing plate and the luffing wire rope, and the linear deformation characteristic of the luffing plate and the luffing wire rope under the temperature load is utilized, the linear thermal expansion coefficient and the temperature load are set, the length of the unit is shortened at a constant speed, the arm head is driven, In this paper, the temperature load is used instead of the conventional load to solve the problem that the load size and the direction of the pull plate are changing over time, and it is difficult to define the load. The method of the invention comprises the following steps of: firstly, carrying out static analysis on the arm support at various elevation angles by adopting the static calculation module of the ANSYS software, and extracting the axial direction of the main chord rod at various angles in the dangerous section; the axial stress extreme value of the main chord is extracted and compared with the allowable limit, the safety degree of the working condition of the arm is determined, The mechanical analysis is used as a reference. The structural dynamics analysis module of the ANSYS contains the transient analysis module, which can be used as the starting arm. The dynamic analysis of the process is carried out. The axial force time history curve of the main chord in the dangerous section is obtained by setting different starting arm times to obtain the axial force time history curve of the main chord in the dangerous section. The extreme value of the axial stress does not exceed the permissible pole. and can be used as the arm safety time, and the working condition of the arm time is long is taken as the arm mode. Optimize and shorten the arm time. Finally, to verify the correctness of the calculation method of this paper, the QUY70 track lifting is made. The dynamic strain data of the strain gauge on the main chord is sampled by the dynamic strain gauge, the collected strain curve is converted and processed, and the results are compared with the results of the static and dynamic analysis of the finite element. The correctness of the algorithm is verified. The dynamic simulation of the lifting arm of the large-scale crawler crane is carried out, and the method for simulating the partial grounding under the self-weight of the boom and the control method of the arm under the temperature load control are put forward. In this paper, the correctness of the calculation method is verified by the experiment, and the result of this paper can be the actual crane.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH213.3

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