Calculation of dynamic stresses of mobile cranes and truck loading cranes in quasi-static analysis

移动式起重机和汽车装卸起重机的动应力准静态分析计算

基本信息

批准号：
328105817
负责人：
Professor Dr.-Ing. Willibald A. Günthner
金额：
--
依托单位：
Lehrstuhl für Fördertechnik, Materialfluss, Logistik
依托单位国家：
德国
项目类别：
Research Grants (Transfer Project)
财政年份：
2017
资助国家：
德国
起止时间：
2016-12-31 至 2019-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/328105817?language=en
关键词：
Calculation dynamic stresses mobile cranes

项目摘要

In industrial practice, stress analysis for mobile cranes (DIN EN 13000, FEM 5.004) and loader cranes (EN 12999) is carried out by quasi-static calculations. Generally, loads due to acceleration of the crane drives are determined by rigid body kinetic models or they are based on experience. During the calculation of the load effects, dynamic factors are used to take elastic effects into consideration. Within the preceding research project, maximum dynamic stresses of lattice boom cranes during the operations hoisting, luffing and slewing were determined by dynamic finite element calculations. A comparison with the quasi-static design according to the standards partially showed large deviations between the two calculation types. On account of the system similarity, the results of the research project are also valid for loader cranes. To avoid the mistakes of the design loads according to standard, dynamic finite element calculations for crane design can be used in accordance with the parent crane standard EN 13001-1. However, this approach is hardly feasible in industrial applications, since this would multiply computation time. Therefore it is desirable to develop vibration models which represent the maximum dynamic stresses by quasi-static loads. The preceding research project showed that vibration models based on a single-mass oscillator provide good estimations of the dynamic factors for simple boom systems. Based on these results, a vibration model using mode superposition has been developed. It is suitable for the analysis of boom systems of any complexity. In a sample application crane slewing was described very well. This vibration model shall be examined systematically in the requested transfer project. Its industrial application is tested both by a manufacturer of mobile cranes and a manufacturer of loader cranes. All required algorithms are programmed by the chair fml and are then integrated in the companies computing environments. In order to verify the achievable accuracy, the chair fml compares the results of dynamic finite element calculations with those of the quasi-static calculations based on the vibration model. All common set-ups and jib lengths are investigated. The companies assess the vibration model in terms of its practical applicability and work out differences to previous calculation methods. To verify the results on an experimental basis the companies carry out measurements for selected operations. The successful completion of the research project would provide an industrial-grade, standard-compliant design method that combines the accuracy of dynamic FE-calculations with the effectiveness of quasi-static analysis.

在工业实践中，移动式起重机（DIN EN 13000、FEM 5.004）和随车起重机（EN 12999）的应力分析是通过准静态计算进行的。一般来说，由于起重机驱动器的加速而产生的载荷由刚体动力学模型确定或者基于经验。在计算荷载效应时，使用动态因子来考虑弹性效应。在之前的研究项目中，通过动态有限元计算确定了桁架臂起重机在起升、变幅和回转操作过程中的最大动应力。与根据标准的准静态设计进行比较，部分显示两种计算类型之间存在较大偏差。由于系统相似，该研究项目的结果也适用于随车起重机。为了避免根据标准设计载荷的错误，可以根据起重机父标准 EN 13001-1 使用动态有限元计算进行起重机设计。然而，这种方法在工业应用中几乎不可行，因为这会增加计算时间。因此，需要开发代表准静态载荷的最大动态应力的振动模型。先前的研究项目表明，基于单质量振荡器的振动模型可以很好地估计简单吊杆系统的动态因素。基于这些结果，开发了使用模态叠加的振动模型。它适用于分析任何复杂性的吊杆系统。在示例应用程序中，对起重机回转进行了很好的描述。应在所请求的转移项目中系统地检查该振动模型。其工业应用经过了移动式起重机制造商和随车起重机制造商的测试。所有必需的算法均由主席 fml 编程，然后集成到公司的计算环境中。为了验证可达到的精度，椅子fml将动态有限元计算的结果与基于振动模型的准静态计算的结果进行了比较。研究了所有常见的设置和臂长。两家公司评估了振动模型的实际适用性，并找出了与之前计算方法的差异。为了通过实验验证结果，公司对选定的操作进行了测量。该研究项目的成功完成将提供一种工业级、符合标准的设计方法，该方法将动态有限元计算的准确性与准静态分析的有效性相结合。