折曲胶接接头应力分布的数值分析

运用有限元法研究了偏轴、同轴和折曲型等三种单搭接胶接接头的工作应力分布规律。结果表明：与其他两种接头相比,折曲型单搭接胶接接头可有效降低搭接区端部的剥离应力和剪切应力峰值;在数值分析所用参数及条件下,Ⅰ型折曲接头的剥离应力降幅超过了75％,其他峰值应力的降幅也超过了45％～50％,并且应力分布趋于均匀;Ⅰ型折曲接头使出现应力峰值的位置从搭接区的端部转移至中部,从而显著提高了接头的承载能力,是一种优于普通同轴接头的胶接接头形式;对于受剪切载荷作用的接头而言,采用Ⅱ型折曲接头更为合理,可进一步提高接头承受剪切载荷的能力。     

折曲胶接接头应力分布的数值分析

运用有限元法研究了偏轴、同轴和折曲型等三种单搭接胶接接头的工作应力分布规律。结果表明:与其他两种接头相比,折曲型单搭接胶接接头可有效降低搭接区端部的剥离应力和剪切应力峰值;在数值分析所用参数及条件下,I型折曲接头的剥离应力降幅超过了75%,其他峰值应力的降幅也超过了45%～50%,并且应力分布趋于均匀;I型折曲接头使出现应力峰值的位置从搭接区的端部转移至中部,从而显著提高了接头的承载能力,是一种优于普通同轴接头的胶接接头形式;对于受剪切载荷作用的接头而言,采用II型折曲接头更为合理,可进一步提高接头承受剪切载荷的能力。     

同轴单搭接胶接接头应力分布的探讨

利用有限元方法研究了偏轴单搭接胶接接头和同轴单搭接胶接接头的力学性能.结果表明,同轴单搭接胶接接头可以使接头搭接末端的弯矩变为零,进而有效地降低剥离应力的峰值,减轻剪切应力的集中程度,是一种较为合理的胶接接头形式.     

同轴单搭接胶接接头力学性能的研究

利用有限元方法研究了偏轴单搭接胶接接头和同轴单搭接胶接接头的力学性能,结果表明：同轴单搭接胶接接头可以使接头趾部的弯矩为零,进而有效地降低剥离应力的峰值和减轻剪切应力的集中程度,是一种极为合理的胶接接头形式。     

冲击载荷作用下胶层厚度对金属双搭接胶接接头应力分布的影响

采用LY12铝合金材料在Ansys12.0软件平台上建立环氧树脂胶粘剂双搭接胶接接头有限元模型进行分析,着重考察了在冲击载荷作用下胶层厚度的改变对胶接接头应力分布的影响。研究结果表明:在一定范围内,随着胶层厚度的增加,胶接接头中最大应力值逐渐下降,而最小应力值开始先下降,在胶层厚度为0.4 mm时最小,之后应力值又继续增大,且最大应力值总是出现在胶层界面的边缘处;在冲击速率为3.4 m/s时,胶接接头在0.4、0.6 mm的胶层中节点的轴向应力S_x、剥离应力S_y、剪切应力S_xy、第一主应力S₁、等效应力S_eqv随着胶层厚度的增加,波动范围变窄,应力峰值也变小,而胶层厚度为0.2 mm时应力值波动异常剧烈,峰值很大。     

单搭接胶接接头胶层的拓扑优化

利用有限元法,对单搭接胶接接头胶层进行拓扑优化,寻求胶粘剂最佳分配.结果表明,合理的胶粘剂分配能够在不影响接头整体力学性能的前提下,极大限度地减少胶粘剂的用量,且使胶粘剂中剪切应力分布更为均匀.     

汽车用镀锌板单搭接胶接接头强度影响因素研究

针对不同种类汽车用镀锌板单搭接胶接接头强度的影响因素进行了研究分析.考察了不同腐蚀介质及汽车涂装工艺对汽车板胶接接头性能的影响,并深入研究了其失效机理.研究结果表明:汽车板材料的屈服强度、材料厚度以及胶层厚度等均会对胶接接头的力学性能产生一定的影响;为保证胶接工艺在汽车车身结构中发挥最佳的力学性能,且与电泳工艺段同步,...     

胶粘剂弹性模量对折曲胶接接头应力分布的影响

通过ANSYS有限元软件建立了折曲胶接接头的弹塑性有限元模型,考察了胶粘剂的力学性能参数弹性模量对其应力分布的影响。研究结果表明:四种不同的胶粘剂,其弹性模量越大,胶层中各应力的峰值越大,搭接区被粘物剥离应力峰值逐渐呈现出上升的趋势;当胶粘剂弹性模量为50 MPa时,被粘物的各应力分量存在较大的应力尖角(应力集中现象)。     

斜削对折曲胶接接头的应力分布影响

采用弹塑性有限元法,研究了被粘物自由端外侧、内侧斜削角度对铝合金单搭接折曲接头中应力分布的影响。结果表明:被粘物自由端经外斜削处理后,胶层中间段的各应力分布无明显变化;外斜削角度越大,剥离应力峰值越高;被粘物自由端经内斜削处理后,内斜削角度越小,胶层端部的轴向应力峰值、剪切应力峰值越小,但剥离应力峰值越大。综合考虑胶层中部的应力分布情况,选择内斜削角度为5°时较适宜。     

搭接长度对钛合金-芳纶纤维复合材料单搭接接头胶接性能的影响

采用钛合金与芳纶纤维复合材料制备不同搭接长度的单搭接接头。利用数字图像相关技术(DIC)、万能试验机等表征方法,对接头拉伸应变与极限载荷进行表征,研究了搭接长度对异质材料单搭接接头胶接性能与破坏模式的变化规律。结果表明,随着搭接长度的增加,单搭接接头极限载荷提升,胶接强度降低,高搭接长度接头出现渐进损伤;偏心弯矩引起的接头偏移减少,搭接部位纵向应变区域面积占比降低;芳纶纤维复合材料层间破坏模式增多,钛合金-胶层界面破坏模式减少,剥离复合材料层数增加。     

Nonlinear stress analysis in adhesively bonded single-lap joint

In this investigation, an analytical elastic–plastic solution was proposed for a single-lap joint. A ductile adhesive joint material was used as the bond material. FM-73 was utilized in the study. The influence of the bending moment was neglected in the solution. The solution was modified for shear stresses. The analytical solution was compared with the FEM solution. An ANSYS 10.0 solution was employed in the numerical solution. Both solutions were compared with each other. These two solutions produced close agreements.     

同轴胶接接头峰值剪切应力的正交法分析

运用正交试验法研究了几何参数,如胶层厚度、被粘物厚度和搭接长度对铝合金同轴接头峰值剪切应力的影响。通过有限元的极差分析、方差分析、最优方案的平均工程等试验分析,研究结果表明:最优方案为A_2B_1C_4,即在一定几何参数变化范围内,搭接长度越长,被粘物厚度越薄,胶层的峰值剪切应力越小;随着胶层厚度的增加,胶层的峰值剪切应力先减小后增大。     

Two dimensional analysis for an adhesively bonded composite single-lap joint based on flexible interface theory

An improved two-dimensional model based on flexible interface theory is proposed for an adhesively bonded composite single-lap joint. In the modified model, the adherends are treated as a Timoshenko beam, and the adhesive layer is assumed to be an Euler–Bernoulli beam. The peel stress and shear stress across the adhesive thickness varied. Additionally, the zero shear stress condition at the free end of the adhesive layer was satisfied. Based on the displacement compatibility condition of a flexible interface, the governing differential equations for the internal forces are derived. The stress distributions of the adhesive layer can be obtained by solving the governing differential equations. A comparison of the results between the modified model, existing classical models, and finite element results indicate that the improved two-dimensional model can determine the stress distribution of the adhesive with high accuracy. Finally, the effects of the thickness ratio, Young’s modulus ratio, and interfacial compliance on the stress distribution of the adhesive are studied using the improved model.     

单搭接胶接接头的拓扑优化

在有限元方法的基础上，利用变密度法对单搭接胶接接头搭接区域的被粘物形状进行了拓扑优化，通过曲线拟舍得到了较为合理的轮廓。拓扑优化的结果表明：在体积减少20％的情况下。胶接结构的强度不会降低；经拓扑优化后，胶层中剪切应力的峰值比优化以前增加不大，约1％。     

Numerical and experimental investigations of the dynamic response of bonded beams with a single-lap joint

The need to design lightweight structures and the increased use of lightweight materials in industrial fields, have led to wide use of adhesively bonding in recent years. In the design of mechanical systems, which consist of adhesively bonded joints, for minimum vibration response, a specific knowledge of the damping capacity of the component materials and joints is important. It is believed that adhesively bonded joints act to augment the system damping capacity in view of the increasing use of viscoelastic materials in their design. The aim of this paper is to provide an efficient numerical technique for the prediction of the dynamic response of bonded beams with a single-lap joint and to validate the predictions via experimental tests. The finite element method was used to predict the natural frequencies, mode shapes and frequency response functions of the beams. The dynamic test software and the data acquisition hardware were used in the experimental measurement of the dynamic response of the joints. The frequency response functions of the joints of different adherend widths and of different adhesive layer thickness were measured. The frequency response functions and mode shapes predicted using the finite element method were compared with those measured experimentally. The coordination of the numerical and experimental techniques makes it possible to find an efficient tool for studying the dynamic response of bonded beams with a single-lap joint.     

复合材料单搭多钉连接钉载分配研究

为了研究多钉连接载荷分配,设计了复合材料4钉单搭连接拉伸试验件,测量了试验件拉伸过程中的应变分布,并计算出各钉的承载。结果表明,单搭接连接件由于次弯曲影响很难准确测量出载荷分布;4钉承载比例不均匀,中间两钉承载较小,外侧两钉承载较大。