ZL50装载机后车架有限元动态分析

本文应用大型通用线性结构分析程序SAP5,对ZL50装载机后车架进行了静、动态分析,计算了结构的特征值,应用振型迭加法计算分析了后车架的瞬态响应,摸清了后车架实际作业状态下的位移,应力时间历程及其分布规律。     

装载机后车架失效原因分析

新设计的某型号装载机后车架,在做台架试验过程中出现了断裂,针对这一情况,用美国大型有限元分析软件NASTRAN对该结构进行了强度分析.阐述了用有限元法对后车架进行强度分析的建模过程,并对分析结果进行了分析.结果表明,由于后车架设计存在缺陷,从而导致某应力集中处应力过高,而且应力过高点是在焊缝部位,这就更加增大了断裂的可能性,说明后车架存在设计缺陷是导致其断裂的主要原因.针对这一情况,设计了一种新型结构,新结构一方面避免了在关键部位存在焊缝,同时降低了最大应力值.经再一次分析表明,新结构强度比原结构有了很大提高,理论上满足设计要求.在其投入市场以来,新型后车架并未发生断裂现象,从而表明查找出的断裂原因正确,对原结构的修改合理.时也表明所建立的有限元模型适用,分析结果可靠.     

装载机前车架断裂解决方案的研究

采用三维CAD软件Pro／E建立ZL50装载机前车架三维实体模型,运用其两个软件之间的数据接口,在有限元软件ANSYS中对前车架三种典型工况中最恶劣的工况进行有限元分析;利用有限元分析的量化结果,有针对性的快速找出ZL50前车架结构强度存在的问题,并对其进行改进设计,以彻底解决前车架的断裂问题。     

ZL30F装载机前车架焊接工艺改进

针对ZL30F装载机前车架焊后变形超差率较高的问题,通过分析前车架的具体结构形式,制定并采用了合理的焊接工艺,使前车架的焊后变形得到了有效控制。     

装载机后车架槽形大梁焊接制造法

用标准槽钢制造装载机后车架的大梁,不能充分保证质量要求。本文介绍用16Mn板材焊制槽形大梁的结构、接头设计、焊接工艺及变形控制,解决了槽钢大梁强度不足,易损坏(开裂)问题。     

全液压履带式装载机车架有限元动力学分析

车架作为装载机的重要支撑部分,其结构除了需要满足一般静强度、刚度要求外,动态特性对于装载机的整体性能有着重要的影响。针对全液压履带式装载机车架,运用Pro/E软件创建实体模型,有限元软件Hypermesh做前后处理器,用Nastran软件进行动力学分析。分析了车架的固有频率和振型,在外载荷作用下的车架应力变化,在随机载荷作用下的瞬态响应分析,在发动机激励下的频率响应情况等。针对分析结果对车架设计提出了相应的改进方案,避免在工作中出现共振、过载及大的变形等情况的发生。     

全液压履带式装载机车架有限元动力学分析

针对ZY65B全液压履带式装载机车架,运用Pro/E软件创建实体模型,用有限元软件Hy-permesh做前后处理器,以Nastran软件进行动力学分析。分析车架的固有频率和振型,在外载荷作用下的车架应力变化,车架的频率响应情况,提出改进方案,避免出现共振、过载和大的变形等情况。     

装载机后车架镗夹具设计与分析

铰接转向装载机后车架是整机的承载骨架,加工时主要考虑三组孔系：连接前后车架的铰接座孔（铰接孔）,连接转向液压缸的后支座孔（转向孔）,连接副车架支承架的支承架孔（连接孔）。孔系间的精度要求见图１,其中要求转向孔组对铰接孔组的平行度０．１ｍｍ,铰接孔组对连接孔组的垂直度０．６ｍｍ;孔组内部同轴度要求：两转向孔之间为Φ０．０４ｍｍ,两铰接孔为Φ０,１５ｍｍ。 一般对后车架的传统加工方法是：副车架支承架、转向液压缸后支座镗后焊接,整体组焊后划线,在Ｔ６１２镗床上按线镗铰接孔。这种工艺流程焊接变形大,没有…     

装载机前车架有限元参数化建模

装载机前车架是结构复杂的承载构件。本文针对某厂ZL60D装载机前车架，开发了有限元参数化建模程序，并与通用微机有限元程序SuperSAP求解模块接口，形成便于工程使用的专用分析软件。文中介绍了建模程序的结构组成及各功能子程序，并用此软件对该车架进行了有限元建模分析。     

倾斜式施工电梯导轨架计算

对倾斜式施工电梯导轨架作受力分析,并建立力学模型。然后,分别用弹性支承连续梁理论和有限元法,对结构进行稳定性和刚度计算。在有限元分析中,先将结构看作是由梁单元和弹簧元组成的结构,对整个结构连同附壁撑进行分析。然后,对离桥塔较远的几跨,将结构进一步细化,看作是由许多杆单元组成的空间桁架式结构。这些方法不仅适用于倾斜式施工电梯的导轨架,也适用于附着式塔式起重机的塔身和直立式施工电梯的导轨架。     

给水管道贴边岔管节点的有限元分析探讨

贴边岔管是钢管分岔节点形式的一种,通过贴焊补强板加强钢管由于开孔导致的承载力削弱。本文采用弹塑性有限元方法分析了不同直径比、不同分岔角度的贴边岔管在正常使用状态和极限工作状态下的受力行为,得到两种工况下岔管节点的应力分布和变形形状。对贴边岔管节点的补强板构造形式进行参数化分析,得到各组补强板补强作用下贴边岔管的应力分布及变形状态,提出不同贴边岔管的有效补强板尺寸,可以为实际工程提供参考依据。本文研究表明有限元方法在贴边岔管分析中有独特优势。     

装载机工作装置摇臂的有限元分析及优化

使用ＵＧ和ＭＳＣ／Ｎａｓｔｒａｎ有限元分析软件,对某型号轮式装载机摇臂进行结构静力分析,研究铸造结构改为钢板焊接结构对工作装置的影响,确定焊接结构钢板的合理布局,实现产品优化。     

Mechanism investigation of welding induced buckling using inherent deformation method

Due to the increasing use of thin plates in lightweight welded structure, welding induced buckling may occur in such thin plate welded structure. In this study, welding induced buckling of thin plate welded structure is investigated using the eigenvalue analysis and elastic Finite Element (FE) analysis based on inherent deformation theory, and the mechanism of welding induced buckling is clarified.Bead-on-plate welding is first examined. Measured out-of-plane welding distortion indicates that saddle type buckling is produced after cooling. Eigenvalue analysis shows the computed lowest buckling mode is the saddle type and the corresponding critical force is less than the applied tendon force evaluated by Thermal–Elastic–Plastic (TEP) Finite Element (FE) analysis beforehand. Using elastic Finite Element (FE) analysis in which all components of inherent deformation are used and also considering initial deflection, out-of-plane welding distortion is predicted with high accuracy compared with measurement. It is also concluded that tendon force (longitudinal inherent shrinkage) is the dominant reason of buckling and it determines the buckling mode, and initial deflection and inherent bending are considered to be disturbances which trigger buckling.Later, a thin plate stiffened welded structure with fillet welded joints is examined. Although welding did not induce buckling of plate fields in bending modes in the considered thin plate stiffened welded structure, the whole stiffened welded structure buckles in a twisting mode, while plate panels remain unbuckled. Eigenvalue analysis gives the twisting buckling mode as the lowest buckling mode. However, in stiffened welded structures, not only tendon force (longitudinal inherent shrinkage) but also transverse inherent shrinkage is responsible for buckling. The good agreement between computed and measured out-of-plane welding distortion shows that the elastic Finite Element (FE) analysis using inherent deformation theory is an advantage of the computational approach to predict welding distortion in large-scale and complex welded structure with enough computational accuracy.     

碳纤维布加固钢筋混凝土梁变形计算分析

在对碳纤维布加固性能研究的基础上,利用钢筋混凝土结构设计中的梁理论,推导并验算了粘贴碳纤维布加固钢筋混凝土梁变形的计算公式,分析了影响碳纤维布加固钢筋混凝土梁变形值大小的因素.     

ROBOT软件在特种结构计算中的应用

结合实例介绍有限元结构分析软件ROBOT在特种结构空间分析中的应用。     

Analysis of coupled gas flow and deformation process with desorption and Klinkenberg effects in coal seams

Coupled gas flow and solid deformation in porous media has received considerable attention because of its importance in pneumatic test analysis, contaminant transport, and gas outbursts during coal mining. Gas flow in porous media is quite different from liquid flow due to the large gas compressibility and pressure-dependent effective permeability. The dependence of gas pressure and gas desorption on gas permeability has a significant effect on gas flow, but has been ignored in most previous studies. Moreover, solid deformation has a direct impact on the porosity, which also leads to desorption or sorption of methane in the coal seam. In this study, a coupled mathematical model for solid deformation and gas flow is proposed and is implemented using a finite element method. The numerical code is used to solve the gas flow equation with Klinkenberg effect, and is validated by comparison with available analytical solutions. Then, it is used to simulate the coupled process during gas migration in a deformable coal seam. The numerical results indicate that the desorption and Klinkenberg effects and mechanical process effect make a significant contribution to gas flow in the coal seam. Without considering the desorption and Klinkenberg effects and the coupling action of mechanical process, the gas pressure in the coal seam would be underestimated.