【作者】 王涛；

【导师】 成凯；

【作者基本信息】 吉林大学 ， 工程硕士（专业学位）， 2024， 硕士

【摘要】 现代全球经济的快速增长催生了众多的工程项目,特别是在石油化工、风能和核能领域的建设,为履带起重机创造了优越的发展环境。在现代化的建设过程中,履带起重机成为了不可或缺的工程设备。而伸缩臂履带起重机在设计时,鉴于作业环境的多样性和特定的工作条件,如带载行驶和爬坡等,需要满足相应的标准和要求。伸缩臂履带起重机的设计质量是确保其起重能力和安全运行的关键因素。为此,开展力学分析以验证设计的有效性显得尤为重要。通过这些分析,不仅可以确认设计的合理性,还可以基于分析结果提出针对性的改进措施和优化方案,从而为伸缩臂履带起重机的设计提供精确的计算支持。在确保产品性能和可靠性的基础上,针对伸缩臂履带起重机的结构开展轻量化研究,从而节省材料,降低成本,这已经变成了伸缩臂履带起重机制造商普遍追求的目标。因此,对伸缩臂履带起重机的轻量化显得尤为关键。本文的研究对象是某企业某型号伸缩臂履带起重机的转台和下车结构,对其进行强度、刚度、模态、疲劳、屈曲稳定性分析和轻量化设计。主要研究内容与结论如下:(1)详细叙述了伸缩臂履带起重机研究的起源和背景,并广泛地总结了国内外伸缩臂履带起重机的发展研究现状,包括其轻量化设计的研究现状。详细论述了对伸缩臂履带起重机的转台和下车结构开展深层次的有限元分析,以及轻量化设计的理论和现实意义。(2)介绍了常见的伸缩臂履带起重机转台和下车的主要结构形式,利用Hyper Mesh软件完成转台和下车结构几何模型的简化和网格的划分。为了保证模型的精确性,为每个部件选择了适当的单元类型和材料属性,进而构建了每个部件的有限元分析模型。最后,运用ANSYS软件完成了下车结构接触区域的选择和接触参数的设置。(3)考虑到伸缩臂履带起重机的转台和下车的结构特性以及受力情况,选择了三种不同的工况进行静力学分析,并从这些工况中提取了计算数据。经过对计算所得的位移和应力数据的深入分析,确认了该结构满足刚度和强度的标准,并选择了典型的工况来进行模态、屈曲和疲劳的分析,并对模态计算得出的转台和下车结构的固有频率进行了深入研究,以确保这些结构不会出现共振的情况。基于屈曲计算方法对转台结构进行分析,确定其不会发生屈曲失效并具有稳定性。基于疲劳分析,确定转台和下车结构不会发生疲劳破坏,满足设计要求。(4)针对结构较为复杂的伸缩臂履带起重机转台机构,利用Hyper Works软件在基于变密度法的条件下来进行其拓扑优化。首先,通过构建一个转台的等效模型,并施加了基于最大许用应力和体积分数的约束条件,以最小化柔度作为优化目标,对转台结构执行了单一工况下的拓扑优化。研究结果表明了仅在单一工况下实施拓扑优化的不足之处,并突出了考虑进行多工况拓扑优化的重要性与必要性。基于这一发现,挑选了合适的权重因子,对转台结构实施了多工况的拓扑优化。依托于多工况优化的成果,结合制造工艺的实际要求,对转台结构进行了进一步的合理设计调整。为了验证设计的可靠性,在极限工况下对经过优化的转台结构进行了有限元分析。结果显示,在满足刚度、强度、模态和疲劳的要求下,转台的重量减少了14.17%,达到了轻量化目标。(5)基于三种不同工况的有限元分析,确定了伸缩臂履带起重机下车结构的最危险工况。针对这一极限工况,选取下车结构中部分板材的厚度作为尺寸优化的变量,并以最小质量为目标函数进行轻量化设计。综合优化结果和制造工艺要求,制定了最优尺寸调整方案并重建了下车结构的有限元模型。在极限工况条件下对优化后的模型进行了验证分析。结果显示,在满足强度、刚度、模态和疲劳要求的前提下,下车结构的重量降低了12.4%,达到了轻量化目标。综上所述,通过对伸缩臂履带起重机的转台和下车结构进行多工况的有限元分析,本文验证了其结构的可靠性、稳定性和安全性。基于此,对转台和下车的结构进行了轻量化的深入研究,在减轻结构重量的同时,还有效降低了生产成本,提升了整体的结构性能。更多还原

【Abstract】 The rapid growth of the modern global economy has given rise to numerous engineering projects,particularly in the construction of the petrochemical,wind energy,and nuclear energy sectors,creating a favorable development environment for Telescopic crawler cranes.When designing crawler cranes,it is necessary to take into account the diversity of operating environments and specific working conditions,such as traveling with loads and climbing slopes,and to meet corresponding standards and requirements.Therefore,based on these analysis results,it is essential to propose reasonable improvement and optimization measures and implement mechanical analysis,thus offering an accurate basis for calculation.On the basis of ensuring product performance and reliability,lightweight research is conducted on the structure of telescopic crawler cranes to save materials and reduce costs.Therefore,studying the lightweight of telescopic crawler cranes is particularly crucial.The research object of this article is the turntable and lower structure of a certain model of telescopic crawler crane in a certain enterprise,and its strength,stiffness,mode,fatigue,buckling stability analysis and lightweight design are carried out.The main research content and conclusions are as follows:(1)This article provides a detailed description of the origin and background of research on telescopic crawler cranes,and extensively summarizes the current development and research status of telescopic crawler cranes both domestically and internationally,including the research status of their lightweight design.Detailed discussion was conducted on the deep level finite element analysis of the turntable and lower structure of the telescopic crawler crane,as well as the theoretical and practical significance of lightweight design.(2)Introduced the main structural forms of the common telescopic arm crawler crane turntable and lower carriage.The geometric models of the turntable and lower carriage structures were simplified and the mesh was divided in Hyper Mesh software.In order to ensure the accuracy of the model,appropriate element types and material properties were selected for each component,and a finite element analysis model for each component was constructed.Finally,ANSYS software was used to select the contact area of the vehicle structure and set the contact parameters.(3)Considering the structural characteristics and stress conditions of the turntable and lower carriage of the telescopic crawler crane,three different working conditions were selected for static analysis,and calculation data was extracted from these working conditions.After in-depth analysis of the displacement and stress data obtained from the calculation,it was confirmed that the structure meets the standards of stiffness and strength,and typical working conditions were selected for modal,buckling,and fatigue analysis.The natural frequencies of the turntable and vehicle structures obtained from modal calculations were thoroughly studied to ensure that these structures do not exhibit resonance.Based on the buckling calculation method,analyze the turntable structure to determine that it will not experience buckling failure and has stability.Based on fatigue analysis,it is determined that the turntable and vehicle structure will not experience fatigue damage and meet the design requirements.(4)For the complex structure of the turntable mechanism of the telescopic crawler crane,the topology optimization is carried out using Hyper Works software based on the variable density method.Firstly,by constructing an equivalent model of the turntable and applying constraints based on maximum allowable stress and volume fraction,the optimization objective is to minimize flexibility.Using the Opti Structure module in Hyper Works software,topology optimization was performed on the turntable structure under a single operating condition.The research results clearly demonstrate the shortcomings of implementing topology optimization only under a single operating condition,and highlight the significant importance and necessity of considering multiple operating conditions for topology optimization.Based on this discovery,suitable weighting factors were selected and topology optimization of the turntable structure under multiple operating conditions was implemented.Based on the results of multi working condition optimization and combined with the actual requirements of manufacturing technology,further reasonable design adjustments have been made to the turntable structure.In order to verify the reliability of the design,finite element analysis was conducted on the optimized turntable structure under extreme operating conditions.The results showed that,while meeting the requirements of stiffness,strength,modal and fatigue,the weight of the turntable was reduced by 14.17%.(5)Based on finite element analysis of three different working conditions,the most dangerous working condition for the lower structure of a telescopic crawler crane was determined.For this extreme working condition,the thickness of some panels in the car structure was selected as the variable for size optimization,and the minimum mass was used as the objective function for lightweight design.Based on the comprehensive optimization results and manufacturing process requirements,the optimal size adjustment plan has been developed.Subsequently,the finite element model of the vehicle structure was reconstructed based on this plan,and the optimized model was validated and analyzed under extreme operating conditions.The results show that,under the premise of meeting the requirements of strength,stiffness,modal and fatigue,the weight of the vehicle structure has been reduced by 12.4%.In summary,this dissertation verifies the reliability,stability,and safety of the turntable and lower structure of the telescopic crawler crane through finite element analysis under multiple working conditions.Based on this,in-depth research has been conducted on the lightweight structure of the turntable and the vehicle,which not only reduces the weight of the structure,but also effectively reduces production costs and improves the overall structural performance.更多还原