Papers by Keyword: Single-Lap Joint

Abstract: Fused Deposition Modeling (FDM) is one of the most common polymer 3D printing technologies used in many applications today. However, limited volume capacity for 3D printing large parts or components is the usual downside of this technology, especially desktop 3D printers. Hence, to offset this limitation, the 3D-printed parts are often designed in multiple pieces and assembled after printing, which requires post-processing called cold welding. Such welds are also quite strong but not as strong as a single-piece print. Therefore, finding suitable parameters or settings that can provide substantial strength for cold-welded 3D-printed parts will be beneficial. This study aims to determine the failing behavior and shear strength of ABS FDM 3D-printed single-lap joint using ABS glue as adhesive. Specimens were printed with varying raster angles (+45^o/-45^o and 0^o/90^o) and layer thickness (290 μm, 190 μm, and 90 μm) to investigate the effects on the adhesion or shear strength and failure mode of the acetone welded 3D-printed joints. Results show that raster angle and layer thickness significantly affected the shear strength of acetone welded materials. Single-lap joint test sample printed with +45^o/-45^o raster angle reveals higher shear strength than specimens printed with 0^o/90^o raster angle. Results also indicated that the gaps between the raster and voids between adjacent filaments of 3D-printed parts affects the adhesion and failure mode of a single-lap joint.

Abstract: Adopting self-piercing riveting (SPR) joining, a new light sheet material joining method, to examine the joining of copper-titanium alloy (H62-TA1) sheet and titanium-aluminum alloy (TA1-Al5052) sheet. Also, using quasi-static mechanical test to figure out mechanical properties of H62-TA1 SPR single-lap joint and TA1-Al5052 SPR single-lap joint. In this study, using Dixon guidelines to eliminate abnormal value and adopting coefficient of variation method to validate reliability of test datum. The results show that failure mode of H62-TA1 joints is that the rivets are pulled out, failure mode of TA1-Al5052 joints is that the bottom sheet fracture. And tensile displacement and energy absorption of H62-TA1 joints are higher than that of TA1-Al5052 joints.

Abstract: A failure analysis of a single-lap single-bolt composite joint with a countersunk fastener was carried out using a progressive damage model. The FE model considering the distributions of fine and coarse meshes, appropriate contact pairs and the bolt preload was established. Based on the analysis, the five stages in the load-displacement curve and the changes of tilt angle were discussed in detail as well as failure contours of hole laminates at typical events during the damage propagation are illustrated. The inherent development tendency of the tilt angle accompanying with the damage propagation in the single-lap joint vividly depict its failure process.

Abstract: Shear stress distribution behaviour of a single-lap bonded joint under tension was investigated using the three-dimensional finite element methods. Five layers of 20-node solid elements were used across the adhesive layer thickness to get accurate indication of the variation of shear stress. The stress distributions in the joint are given by the stress contours. All the numerical results obtained from the finite element analysis show that the spatial distribution of shear stress are similar for all 6 interfaces though the stress values are obviously different. It can also be seen from the results that the left hand region is subjected to very high stress.

Abstract: Three-dimensional (3D) elastic stress distributions in the vicinity of overlap corners of single-lap joints are investigated. A detailed 3D finite element (FE) model is carried out to study the intensity of the in-plane and out-of-plane stress distributions along the plate width direction. The effects of adhesive thickness and Poisson's ratio are also studied. The FE results show the presence of coupled modes at the overlap corners of the joint. In particular, sharp increment of out-of-plane fracture mode very near the lateral free surface of the joint is worth noting.

Abstract: This paper investigates normal stress distribution of a single-lap adhesively bonded joint under tension using the three-dimensional finite element methods. Five layers of solid elements were used across the adhesive layer thickness in order to obtain an accurate indication of the variation of normal stress. All the numerical results obtained from the finite element analysis show that the spatial distribution of normal stress are similar for different interfaces though the stress values are obviously different. It can also be seen from the results that the left hand region, which is very close to the left free end of the adhesive layer, is subjected to very high stress and the magnitude of the normal stress oscillates in value close to the left end of the adhesive layer.

Abstract: The aim of this paper is to investigate the effect of supports on the actual stress distribution of the single-lap adhesive joints under tension using the three-dimensional finite element methods. Five layers of elements were used across the adhesive thickness in order to obtain an accurate indication of the variation of stresses. All the numerical results obtained from the finite element analysis show that the spatial distribution of all components of stress are similar for different interfaces though the stress values are obviously different. The results also show that most of the maximum stresses occur at the interface 1. It can be seen from the results that the stresses are concentrated near the left free ends of the adhesive layer while the centre region of the adhesive layer is mostly stress-free.

Abstract: This paper deals with the effects of mechanical behavior of adhesives on the shear stress distributions of single-lap adhesive joints under tension using the three-dimensional finite element analysis (FEA) technique. Numerical examples are provided to show the influence on the shear stresses of the joints using adhesives of different characteristics which encompass the entire spectrum of viscoelastic behavior. FEA solutions of the shear stress distributions in the adhesive layer have been obtained for four typical characteristics of adhesives. The results indicate that Young’s modulus and Poisson’s ratios of adhesives strongly affect the shear stress distributions of the joints.

Abstract: An investigation was performed to study the response of laminated composites with bolt joints. The configuration was single-lap single countersunk head bolt. The major focus was to characterize bearing behavior of laminates and the effect of some parameters such as lap types, fastener types, hole diameter, and stiffness of lapped plate on the bearing strength and stiffness. For this purpose, hundreds of specimens were tested to obtain ultimate loads and stiffness of joints. According to different configurations of joints, three contrast tests were carried out, and some useful conclusions were drawn. Firstly, comparing the stiffness, the joints with protruding head bolts are slightly stiffer than those with countersunk head bolts. And bearing strength of the joints with protruding head bolts are about 10% higher than those with countersunk head bolts. Secondly, ultimate load and stiffness of single-lap double bolts are similar to double-lap single bolt, which are twice bigger than single-lap single bolt. Thirdly, the stiffness of joints can be improved by using bigger hole diameter or stiffer lapped plates. When the hole diameter and stiffer lapped plates are in a reasonable range, bearing strength increase. However, larger stiffness of joint structure may cause transient breaking, which is dangerous for the structure. So in engineering, it is needed to balance the bearing strength and stiffness of joints.

Abstract: This paper deals with the effects of bending and boundary condition on the stress distribution of a single-lap adhesive joint under tension using the three-dimensional finite element analysis technique. The numerical results obtained from the finite element analysis show that both the left and right hand regions of the adhesive layer are subjected to high stresses. The numerical results also show that most of the extreme stresses occur at interface which is between the adhesive and the upper adherend. It is clear that the stresses are concentrated near the left and right free ends of the adhesive layer while the centre region of the adhesive layer is mostly stress-free. It is also clear that the stress state in this case is mainly dominated by the normal stress components.