Study on Tensile Strength of Composite Double-Lap Joint

2012 ◽  
Vol 157-158 ◽  
pp. 1519-1526 ◽  
Author(s):  
Sui Liu ◽  
Zhi Dong Guan ◽  
Xia Guo ◽  
Dong Xiu Yan ◽  
Ping Chen ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Shear Strain ◽  
Analytical Model ◽  
Shear Failure ◽  
Tensile Load ◽  
Lap Joints ◽  
Plastic Behavior ◽  
Finite Model ◽  
Lap Joint ◽  
Maximum Shear Strain

An experimental and analytical study on ultimate tensile strength of composite double-lap joints with different adhesive thicknesses is employed in the paper，test results indicate the major failure mode of joints is adhesive shear failure and the ultimate strength of joints increasing with thicker adhesive. Analytical model is developed to investigate the adhesive failure of double-lap joint based on the experiments. The model takes into account anisotropy of each ply in the composite laminates and elastic-perfectly plastic behavior of the adhesive in the joints. The validity of analytical model for calculating shear strain/stress distribution is certified by comparing with finite model results. Maximum shear strain criterion is adopted in the analytical model to predict the ultimate tensile load of double-lap joint. Good agreement of the analytical predictions with the experimental results is obtained.

Distribution des contraintes dans les assemblages collés :

1996 ◽  
Vol 84 ◽  
pp. 47-56
Author(s):  
B. Fargette ◽  
Y. Gilibert ◽  
L. Rimlinger
Keyword(s):  
Test Specimen ◽  
Testing Machine ◽  
Tensile Load ◽  
Expansion Method ◽  
Lap Joints ◽  
Experimental Results ◽  
Stress Fields ◽  
Lap Joint ◽  
Single Lap Joints ◽  
Linear Behaviour

We have studied the agreement between theoretical computations and experimental results of surface strains of bonded joints of two types : tenon and mortise, and single-lap joints, for different lengths of the lap. For instance, with the single-lap joint, we have tested four lengths of the overlap from 14 mm to 88 mm. Surface strains are measured by an extensometrical method with electrical gauges, when the specimen is loaded in uniaxial traction on a universal testing machine. Experimental results and computations made by an improved method like the asymptotic expansion method agree, but only if the global traction load applied on the specimen is low, or if the overlap in respect with the others dimensions of the section of test specimen is long. In these joints, effectively, stress fields are disrupted near the butts and become very difficult to compute. Actually, near the ends of the overlap, stresses can reach high limits with only low global load applied on the test specimen. With a short length of the overlap, linear behaviour disappears almost totally because of a strong interaction of the two perturbed fields. On the contrary, with a high length of overlap, stress fields become linear on the major part of the overlap , even with a high tensile load applied on the specimen. So, the length of the overlap has a great effect on the linear behaviour of the joint.

scholarly journals Influence of Rivet Diameter and Pitch on the Fatigue Performance of Riveted Lap Joints Based on Stress Distribution Analysis

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3625 ◽  
Author(s):  
Jintong Liu ◽  
Anan Zhao ◽  
Zhenzheng Ke ◽  
Zhendong Zhu ◽  
Yunbo Bi
Keyword(s):  
Theoretical Model ◽  
Stress Distribution ◽  
Structural Parameters ◽  
Tensile Load ◽  
Lap Joints ◽  
Fatigue Performance ◽  
Fe Model ◽  
Distribution Analysis ◽  
Lap Joint ◽  
Riveted Lap Joints

Interference-fit riveting is one of the most widely used mechanical joining ways in aircraft assembly. The fatigue performance of riveted joints has a significant impact on the service life and reliability of aircraft. In this paper, the fatigue performance of the riveted lap joints with various rivet diameters and pitches are studied based on stress distribution analysis under tensile load. First, a theoretical model of the riveted lap joint under tensile load is developed by using the spring-mass model. The rivet-load stress, bypass stress, and interference stress around the riveted hole are analyzed. Then, the finite element (FE) model of riveted lap joints are established. The influence of rivet diameter and pitch on stress distribution around the riveted hole are discussed. Finally, the fatigue tests are conducted with riveted lap joint specimens to verify the theoretical model and FE results, and a good agreement is observed. Based on the simulation and experimental results, a good combination of structural parameters of the riveted lap joint is found which can optimize the stress distribution around the riveted hole and improve the fatigue life of the riveted lap joint.

Assessment of Fatigue Crack Growth in Imperfect Lap Joint: Part 2 — Crack Propagation Analysis Using “SCANP”

2012 ◽  
Author(s):  
Satoshi Igi ◽  
Yasushi Morikage ◽  
Masaru Wakasa ◽  
Shoichi Yoshida ◽  
Kazuyoshi Sekine ◽  
...  
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Propagation ◽  
Tensile Load ◽  
Lap Joints ◽  
Software System ◽  
Lap Joint ◽  
Crack Face ◽  
Deck Plate ◽  
Bending Load

The deck plates of single-deck-type floating roofs for large oil storage tanks are joined by single-welded Full-fillet lap joints. In areas with frequent strong winds, fatigue cracks sometimes occur in the welds of the deck plate. The aim of the present study is to investigate the effect of the gap imperfection of the lap joints on the fatigue life. In the case that tensile load acted on Full-fillet lap joints, the stress at the crack face becomes larger by gap imperfection of the lap joint. The authors have developed a software system called “SCANP (Surface Crack Analysis Program)”, a software system to evaluate the stress intensity factor, K, and to simulate fatigue crack propagation for surface cracks for arbitrarily distributed surface stresses. The fatigue life of a lap joint was predicted by the “SCANP” using the calculated stresses at the root crack face and the toe crack face. The number of loading cycles to penetration for arbitrary bending load amplitudes and tensile load amplitudes are obtained.

scholarly journals Experimental Investigation on Shear Failure Mechanism of Rock Mass with Intermittent Joints

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Minghui Ma ◽  
Fenhua Ren ◽  
Wensheng Liu
Keyword(s):  
Rock Mass ◽  
Shear Strain ◽  
Failure Mechanism ◽  
Shear Failure ◽  
Shear Fracture ◽  
Shear Loading ◽  
Surface Strain ◽  
Image Correlation ◽  
Maximum Shear Strain ◽  
Natural Rock

There are a large number of discontinuous weak planes distributed in the natural rock mass, which makes the sliding failure of rock mass along the intermittent structural plane very complex. To investigate the shear failure mechanism of rock mass with intermittent joints and study the influence of different joint heights on the shear failure mode of the rock mass, direct shear tests were carried out by presetting a series of jointed rock specimens with different undulating heights. During the shear loading, digital image correlation (DIC) technology was employed to monitor the surface strain field of the specimens in real time. The results show that the fluctuation height has a significant effect on the evolution of shear strain. With the increase of shear load, the maximum shear strain of the jointed specimens with different undulating heights first increases slowly and then increases rapidly. When the undulating height is 5 mm, the failure of the specimen is dominated by the rock sliding along prefabricated joints. When the undulating height is larger than 10 mm, the shear fracture of the rock becomes dominant. With the increase of the undulating height, more penetrating cracks perpendicular to the preexisting joints appear between the serrated surfaces, and the shear fracture phenomenon is more obvious.

scholarly journals Experimental Study on Shear Failure Characteristics of Jointed Rock Mass Based on Direct Shear Tests and Digital Image Correction Techniques

2021 ◽  
Vol 2021 ◽  
pp. 1-16
Author(s):  
Fenhua Ren ◽  
Liwei Zhang ◽  
Xinghui Wu ◽  
Wensheng Liu
Keyword(s):  
Rock Mass ◽  
Shear Strain ◽  
Shear Failure ◽  
Jointed Rock ◽  
Image Correction ◽  
Shear Tests ◽  
Maximum Shear Strain ◽  
Direct Shear Tests ◽  
Discontinuous Joints ◽  
Dip Angle

The instability of rock engineering is normally dominated by the shear failure of rock mass. The dip angle of discontinuous planes widely existing in rock mass is a key parameter affecting the shear strength and failure mode of jointed rock. This paper aims to investigate the influence of discontinuous joints on the shear failure of rock. Direct shear tests are carried out on rock-like specimens with discontinuous joints in different dip angles. During the shear tests, the strain field is monitored in real-time by digital image correction (DIC) technology. Experimental results show that the shear strength, shear strain evolution, and failure mode for the jointed specimens are affected by the dip angles of the discontinuous joints. The maximum shear strain of specimens with joint angles of 45° and 75° increases gradually with the increase of shear loading. The maximum shear strain for the specimens with joint angles of 0°, 15°, 30°, 60°, and 90° increases sharply after the shear load reaches 80% of the peak load. When the joint inclination angle is less than 45°, the crack begins to expand from the joint tip and is interconnected to form a penetrating fracture. When the joint dip angle is greater than 45°, the cracks initiate at the joint tip and then propagate at different paths resulting in multistage shearing and crushing failure.

Gas Metal Arc Welding (GMAW) Process Optimization of a 1.4 mm Uncoated Dual Phase 980 (DP980) Joint for Automotive Body Structural Applications

2010 ◽  
Author(s):  
Ramakrishna Koganti ◽  
Adrian Elliott ◽  
Cindy Jiang
Keyword(s):  
Tensile Strength ◽  
Feed Rate ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Lap Joints ◽  
Lap Joint ◽  
Metal Arc Welding ◽  
Static Tensile ◽  
The Wire ◽  
Wire Feed

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to heat-affected zone (HAZ) at the weld joint. In this study Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 1.4 mm uncoated DP980 to itself was investigated. The objective of the study was to understand the wire feed rate and torch speed influence on lap joint tensile strength (static and fatigue). A two factor, two level, full factorial design of experiment (DOE) was conducted to understand the wire feed and torch speed influence on tensile and fatigue strength of the welded joints. In order to understand the curvature effect, a center point was also included in the experiment. Based on the statistical analysis, neither factor was significant on static tensile strength, however, a two way interaction between wire feed rate and torch speed was significant on static tensile strength. Metallurgical properties of the lap joints were evaluated using optical microscopy. A significant hardness drop of 40% was observed at the HAZ.

Static Tensile Strength of Gas Metal Arc Welded (GMAW) Joints of Uncoated Dual Phase 600 (DP600) Steels

2008 ◽  
Author(s):  
Ramakrishna Koganti ◽  
Sergio Angotti ◽  
Armando Joaquin ◽  
Cindy Ziang ◽  
Chris Karas
Keyword(s):  
Tensile Strength ◽  
Feed Rate ◽  
Gas Metal Arc Welding ◽  
High Strength Steels ◽  
High Strength ◽  
Lap Joints ◽  
Lap Joint ◽  
Static Tensile ◽  
The Wire ◽  
Wire Feed

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to Heat affected Zones (HAZ) at the weld joint. In this study Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 1.5 mm uncoated DP600 to itself was investigated. The objective of the study was to understand the wire feed rate and torch speed influence on lap joint strength. A two factor, two level, full factorial design of experiment (DOE) was conducted to understand the wire feed and torch speed influence on tensile strength. In order to understand the curvature effect, center point was also considered in the experiment. Based on the statistical analysis, wire feed rate was the only significant factor on static tensile strength. Metallurgical properties of the lap joints were evaluated using optical microscopy. Significant hardness drop of 40% was observed at the HAZ.

Gas Metal Arc Welding (GMAW) Process Optimization of 2.0 mm Uncoated Boron Steel to 1.0 mm Usibor® 1500 P Steel Joint for Automotive Body Structural Applications

2010 ◽  
Author(s):  
Ramakrishna Koganti ◽  
Adrian Elliott
Keyword(s):  
Tensile Strength ◽  
Feed Rate ◽  
Arc Welding ◽  
Gas Metal Arc Welding ◽  
Travel Speed ◽  
Lap Joints ◽  
Boron Steel ◽  
Lap Joint ◽  
Metal Arc Welding ◽  
Wire Feed

With the increasing demand for safety, energy saving and emission reduction, Advanced High Strength Steels (AHSS) have become very attractive steels for automobile makers. The usage of AHSS steels is projected to grow significantly in the next 5–10 years with new safety and fuel economy regulations. These new steels have significant manufacturing challenges, particularly for welding and stamping. Welding of AHSS remains one of the technical challenges in the successful application of AHSS in automobile structures due to heat affected zones (HAZ) at the weld joint. In this study, Gas Metal Arc Welding (GMAW) of a lap joint configuration consisting of 2.0 mm uncoated boron steel and 1.0 mm Usibor® 1500 steel was investigated. The objective of the study was to understand the wire feed rate (WFR) and torch (or robot) travel speed (TTS) influence on lap joint tensile strength. Design of Experiments (DOE) methodology was used to understand the process parameter influence on the joint strength. Based on the statistical analysis, wire feed rate and torch travel speed were significant factors on static tensile strength. The interaction effect between wire feed rate and torch travel speed was not significant. Metallurgical properties of the lap joints were evaluated using optical microscopy. Significant drops in hardness at the HAZ were observed on both Usibor® 1500 P and boron steels.

Numerical Analysis of Co-Cured Composite Single Lap Joint with Spew Fillets

2011 ◽  
Vol 279 ◽  
pp. 219-223
Author(s):  
Guo Hua Zhao ◽  
Qing Lian Shu ◽  
Bo Sheng Huang
Keyword(s):  
Finite Element ◽  
Tensile Load ◽  
Lap Joints ◽  
Finite Element Code ◽  
Lap Joint ◽  
Single Lap Joints ◽  
Single Lap Joint ◽  
Static Tensile ◽  
The Subject ◽  
Failure Location

Spew fillet is common in co-cured composite single lap joint. It plays an important role in the safety of the joint. But few attentions were paid to the subject in former investigations. In this paper, co-cured composite single lap joints with spew fillets under static tensile load were investigated numerically using the commercial finite element code ANSYS. The submodeling technique was employed to overcome the problem caused by extra aspect ratio of elements. The computation results indicated that the existence of spew fillets will not change the possible failure location, but will improve the anti-failure performance of single lap joint.

Sign in / Sign up

Export Citation Format

Share Document