复合材料板与金属板榫槽粘接结合有限元分析

榫槽连接是航空结构中常用的一种连接形式。通过对金属板和复合材料板的榫槽粘接部位进行有限元计算，分析简单拉力作用下连接部位的应力分布以及金属板和复合材料板尺寸对最大等效应力的影响。通过比较发现，在所考察范围内榫槽长度、粘接层厚度和板宽度等因素对模型等效应力的影响并不十分显著，而两种材料板之间的相对厚度对最大等效应力影响较大，随着金属板厚度的增大，整个榫槽连接结构的最大等效应力有所减小。     

涡轮盘榫槽工作面波纹问题分析与改善

涡轮盘是烟气轮机的核心零件.针对影响涡轮盘榫槽工作面接触精度的波纹问题,进行了原因分析,并提出预防波纹问题产生的改善措施.所进行的分析与改善有助于改善和提高烟气轮机涡轮盘的加工质量.     

涡轮盘榫槽槽底裂纹损伤分析

本文对某发动机一级涡轮盘榫槽槽底的裂纹损伤从实验研究和理论分析二个视角探究裂纹损伤产生的机理及影响裂纹扩展的因素,为采取行之有效的预防措施提供理论依据。     

隔板燕尾型榫槽工艺方案分析

线切割的主要特点是精度高、工序少、变形小、加工中产生的应力较小,因此对薄壁件的加工有明显的加工优势,燃机隔板的结构正好在此适用范围,文中论述了燃机隔板外环燕尾形榫槽采用线切割加工的工艺适用性。     

空间角度圆盘榫槽液压分度夹具设计

论述了一种拉削空间角度圆盘榫槽的液压分度夹具,详细介绍了该夹具的空间角度计算方法及液压锁紧与分度联动装置。该夹具操作方便,并且配合L7120立式拉床成功地加工出了复杂角度圆盘的榫槽。     

小尺寸轮盘榫槽拉刀结构参数优化设计研究

以拉削成形加工GH4720Li高温合金涡轮盘纵树型榫槽用ASP2015材质拉刀为研究对象,研究了刀具结构参数对拉削力、刃口应力分布等的影响规律及优化方法.以拉刀三维几何模型、GH4720Li合金的室温拉伸力学性能、热物性参数和实际拉削工况为输入参数,建立了拉削的热-力耦合有限元仿真模型,通过拉削实验所测的拉削力与仿真值...     

压气机锥型鼓筒轴榫槽的加工与检测

压气机锥型鼓筒轴为TC4钛合金零件,TC4合金在发动机领域属于难加工的一类材料.压气机锥型鼓筒轴为7个压气机组成的整体结构,该结构形状复杂,其尺寸精度要求高.针对压气机锥型鼓筒轴难加工的外圆榫槽位置,设计了非标榫槽刀片、改善切削参数、调整走刀路线等,结果表明:提出的机加工艺参数以及塞钢珠测量法和成型检测样板测量法,有效...     

涡轮盘榫槽加工技术现状与展望

针对航空发动机和燃气轮机高端动力装备涡轮盘榫槽,从机械加工（包括拉削、铣削、磨削）和特种加工（包括电火花线切割、电解线切割）两方面分析了加工技术的主要特点;从加工工具设计与应用、加工质量评价及控制等方面系统阐述了榫槽加工技术的发展现状,分析了国内外学者在该领域的重要研究成果,最后展望了榫槽加工技术的发展趋势。     

基于ANSYS的输送机中部槽可靠性分析

为探究输送机中部槽的可靠性及寻找优化的可能。利用有限元分析软件ANSYS对输送机中部槽进行静力分析,确定其静态强度满足要求;对其进行带预应力的模态分析发现其动态强度有优化的空间。为中部槽进行结构优化并重新进行静力分析和模态分析,发现其静态强度和动态强度均得到大幅提升。     

航空发动机榫槽拉刀快速设计系统研究与开发

在分析航空发动机涡轮盘榫槽拉刀传统设计过程的基础上,结合某航空企业实际需求,提出一种榫槽拉刀的三维参数化设计方法,通过建立榫槽拉刀三维参数化模型模板,构建模型模板实例库从而实现榫槽拉刀的三维参数化快速设计,避免了大量的参数计算和重复设计,缩短了榫槽拉刀的设计周期、提高了榫槽拉刀的设计效率。     

Pre-stressed adhesive strap joints for thick composite sandwich structures

A simple but effective design to improve the strength of thick adhesive composite strap joints is validated with experiment and finite element method. The strap joint under investigation, with a particular application to naval ship structures, consists of two thick woven E-glass/vinyl ester laminates joined together with two steel doublers. Longitudinal tensile loads are applied to the joints, resulting in large concentrated shear and peel stresses near the free edges of bondlines. The new design intends to reduce the adhesive peel stress by application of through-the-thickness compressive pre-stress along the bondline and thus leads to an increase of joint strength. Experiment results show that all the joint failures are delamination of the top layer of the laminated adherends. The test further confirms that joint strength increases significantly by applying the transverse pre-stress. Finite element analysis reveals that the pre-stress can effectively reduce the magnitude even reverse the sign of the peel stress in the adhesive layer and the adherends. Recessing the adhesive leading edge could magnify the pre-stress effect and reduce the adhesive peel stress, but would increase the shear stress. For those composite joints with low transverse interlaminar strength and susceptible to delamination, this simple design/technique can considerably improve their joint strength.     

复合材料层合板连接件应力分析

复合材料广泛应用于飞机结构中,各部件间的连接主要通过机械紧固件实现。紧固件连接时需要在复合材料上开孔,会导致孔附近的应力集中,同时会破坏纤维的连续性,这便削弱了复合材料结构的承载能力,直接影响飞行安全与使用寿命。基于有限元软件ANSYS,应用参数化设计语言APDL,考虑接触非线性影响,建立了单钉单剪连接件的三维模型,计算连接件的变形及应力分布,为后续复合材料连接件强度分析提供支撑。     

Mechanical behaviour and failure modes of metal to composite adhesive joints for nautical applications

In this paper, the influence of several parameters on the mechanical behaviour and failure modes of hybrid bonded joints aluminium/composite was investigated. Particularly, the effects of metallic surface condition, adhesive properties and thickness on single-lap joint resistance were analysed. To these aims, two adhesives were used and, for each adhesive, two different adhesive thicknesses (0.5 and 1.5?mm) have been investigated. Furthermore, two sets of joints for each adhesive kind and thickness were investigated: the former was obtained using aluminium blanks which were previously mechanically treated with sandpaper (P60) and the latter using aluminium treated with sandpaper and with presence of fillets in the ends of the overlap area. In order to improve the adhesion strength between polymeric adhesive and aluminium, two metal surface treatments have also been performed using a silane coupling agent, ??-glycidoxypropyltrimethoxysilane (??-GPS). The mechanical performances and failure modes were found to be significantly increased using the chemical pre-treatments with ??-GPS silane coupling agent unlike other parameters investigated. As regard the thickness of the adhesive layer, the better value is found to be equal to 0.5?mm, for both adhesives investigated.     

钢塑复合管的强度分析

通过建立复合管力学模型问题,对管道衬里层与管道之间的径向应力、径向位移及金属管道的环向应力进行分析。讨论工程中管道承受载荷时对复合管强度的影响。为管道设计、施工和检验提供理论依据。     

3D finite element analysis of stress distributions and strain energy release rates for adhesive bonded flat composite lap shear joints having pre-existing delaminations

The rate of propagation of embedded delamination in the strap adherend of lap shear joint (LSJ) made of carbon/epoxy composites has been evaluated employing three-dimensional non-linear finite elements. The delamination has been presumed to pre-exist in the thin resin layer between the first and second plies of the strap adherend. The inter-laminar peel and shear stress distributions have been studied in details and are seen to be predominantly three-dimensional in nature. The components of strain energy release rate (SERR) corresponding to the opening, sliding and cross sliding modes of delamination are significantly different at the two fronts of the embedded delamination. The sequential release of multi-point constraint (MPC) finite elements in the vicinity of the delamination fronts enables to simulate the growth of the delamination at either ends. This simulation procedure can be utilized effectively for evaluation of the status of the structural integrity of the bonded joints.     

Strength of threaded joints

Fatigue tests of threaded joints are required to establish their fatigue strength. The manufacture of bolts, screws, pins, and nuts with MJ metric threads is expedient.     

箱形梁焊接结构安全可靠性分析方法

根据概率损伤容限分析及可靠性理论，提出了一种基于箱形梁的焊接结构安全可靠性分析方法，给出了该类结构疲劳裂纹随机扩展过程中较普适的α—αc干涉模型和结构疲劳可靠性表达式。在给定与疲劳寿命有关的各参数条件下求得动态可靠性曲线，从而在箱形梁类的焊接结构设计中，可以很方便地根据可靠性要求，确定或选择设计参数，并在设备使用过程中按周期进行检查和维修。     

滑块式万向接轴的强度和结构分析

通过对多个滑块万向接轴计算工作的总结,介绍了滑块式万向接轴强度分析过程中叉扁头建模时的载荷处理技巧、叉扁头的应力分布规律及不同叉扁头结构对应力的影响等。最后还讨论了滑块式接轴强度有限单元法和经典计算方法的区别及实践应用时的处理方法。     

汽车座椅调角器结构强度分析及改进设计

针对某型汽车座椅调角器在实验过程中发生失效的现象,建立了该型调角器的有限元仿真模型。在实际的实验载荷工况下,对调角器进行结构强度分析。有限元分析的结果所齿板和内齿圈啮合部位最外侧齿根部位应力较大,超过了材料的屈服极限;固定座根部圆角部位应力也较大。通过仿真分析和实验结果进行比较,验证了调角器有限元仿真分析模型的有效性。根据分析结果对调角器的结构进行改进设计,并重新对其进行有限元强度分析。结果表明改进的结构解决了调角器的失效问题,具有一定的工程实用价值。     

基于可靠性理论的卷扬式启闭机开式齿轮的强度分析

基于可靠度分析的基本原理,根据开式齿轮的工作特点及主要失效模式,建立了卷扬式启闭机开式齿轮可靠度分析的数学模型,并结合工程实例进行计算分析。结果表明,可靠度分析方法克服了传统安全系数法的特点,可靠度指标式更为科学的安全指标。