scholarly journals Investigating the Effect of Interface Morphology in Adhesively Bonded Composite Wavy-Lap Joints

2021 ◽  
Vol 5 (1) ◽  
pp. 32
Author(s):  
Roya Akrami ◽  
Shahwaiz Anjum ◽  
Sakineh Fotouhi ◽  
Joel Boaretto ◽  
Felipe Vannucchi de Camargo ◽  
...  
Keyword(s):  
Mechanical Behavior ◽  
Composite Structures ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Tensile Load ◽  
Lap Joints ◽  
Load Level ◽  
Displacement Curve ◽  
Interface Morphology ◽  
Angle Variation

Joints and interfaces are one of the key aspects of the design and production of composite structures. This paper investigates the effect of adhesive–adherend interface morphology on the mechanical behavior of wavy-lap joints with the aim to improve the mechanical performance. Intentional deviation from a flat joint plane was introduced in different bond angles (0°, 60°, 90° and 120°) and the joints were subjected to a quasi-static tensile load. Comparisons were made regarding the mechanical behavior of the conventional flat joint and the wavy joints. The visible failure modes that occurred within each of the joint configurations was also highlighted and explained. Load vs. displacement graphs were produced and compared, as well as the failure modes discussed both visually and qualitatively. It was observed that distinct interface morphologies result in variation in the load–displacement curve and damage types. The wavy-lap joints experience a considerably higher displacement due to the additional bending in the joint area, and the initial damage starts occurring at a higher displacement. However, the load level had its maximum value for the single-lap joints. Our findings provide insight for the development of different interface morphology angle variation to optimize the joints behavior, which is widely observed in some biological systems to improve their performance.

A FEA Simulation Model for Thin-Walled C-Section Composite Beam Assembling With R-Angle Deviation

2014 ◽  
Author(s):  
Hua Wang ◽  
Suo Si
Keyword(s):  
Numerical Model ◽  
Composite Beam ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Element Model ◽  
Load Level ◽  
Compression Tests ◽  
Accurate Analysis ◽  
Angle Deviation ◽  
Thin Walled

There are unavoidable deviations, such as shrinkage and distortions, in the composite detail parts production due to the complexity of composites fabrication. Interests in the assembly analysis of composite beams have led to a need for more accurate analysis especially in the case of fabrication deviations. This work proposes a numerical finite element model of thin-walled C-section composite beam with R-angle deviation for assembling. The rule of Hashin failure combined with cohesive element is applied to study the mechanical performance of the fiber and matrix (implemented as user subroutine UMAT in ABAQUS) while positioning and clamping. Tension and compression tests are carried out based on available standards to determine the C-section beam behavior under load. The testing data validates the proposed numerical model. The numerical model captures the experimentally obtained results with minimal error, and predicts the failure modes successfully. The proposed model allows to determine accurately the first failure location and the associated load level. It will enhance the understanding of the composite components pre-loading analysis, and help systematically improving the composites assembling efficiency in civil aircraft industry.

scholarly journals Microstructure and Mechanical Performance of Additively Manufactured Aluminum 2024-T3/Acrylonitrile Butadiene Styrene Hybrid Joints Using an AddJoining Technique

Materials ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 864 ◽  
Author(s):  
Rielson Falck ◽  
Jorge F. dos Santos ◽  
Sergio T. Amancio-Filho
Keyword(s):  
Composite Structures ◽  
Mechanical Performance ◽  
Acrylonitrile Butadiene Styrene ◽  
Fracture Morphology ◽  
Lap Joints ◽  
Point Of View ◽  
Coated Metal ◽  
Hybrid Joints ◽  
The One ◽  
Butadiene Styrene

AddJoining is an emerging technique that combines the principles of the joining method and additive manufacturing. This technology is an alternative method to produce metal–polymer (composite) structures. Its viability was demonstrated for the material combination composed of aluminum 2024-T3 and acrylonitrile butadiene styrene to form hybrid joints. The influence of the isolated process parameters was performed using the one-factor-at-a-time approach, and analyses of variance were used for statistical analysis. The mechanical performance of single-lap joints varied from 910 ± 59 N to 1686 ± 39 N. The mechanical performance thus obtained with the optimized joining parameters was 1686 ± 39 N, which failed by the net-tension failure mode with a failure pattern along the 45° bonding line. The microstructure of the joints and the fracture morphology of the specimens were studied using optical microscopy and scanning electron microscopy. From the microstructure point of view, proper mechanical interlocking was achieved between the coated metal substrate and 3D-printed polymer. This investigation can be used as a base for further improvements on the mechanical performance of AddJoining hybrid-layered applications.

Analysis of Mechanical Performance Considering Damage Accumulation of Intersecting Joints in Steel Structures

2011 ◽  
Vol 94-96 ◽  
pp. 583-586
Author(s):  
Bao Feng Fan ◽  
Na Yang ◽  
Qing Shan Yang ◽  
Leroy Gardner
Keyword(s):  
Plastic Deformation ◽  
Mechanical Behavior ◽  
Damage Accumulation ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Local Buckling ◽  
Steel Structures ◽  
Steel Tube ◽  
Geometric Parameters ◽  
Mechanical Behaviors

The mechanical behaviors of intersecting joints considering damage accumulation in steel tube structures is analyzed through the FE-program ABAQUS. The stress characteristic and failure modes of these joints are concluded. Especially, it has been analyzed influence of the change of geometric parameters to mechanical behavior of joints. Finally, the results indicate the joints have a good mechanical performance and good plastic deformation as to excessive local buckling of chord under the loads.

Experimental Investigation on Adhesive Bonded Joints of Carbon Fiber Composite Laminates Containing Disbond Defect

2017 ◽  
Author(s):  
Ping Qiu ◽  
Jianfeng Shi ◽  
Jinyang Zheng
Keyword(s):  
Carbon Fiber ◽  
Adhesive Bonding ◽  
Phased Array ◽  
Failure Modes ◽  
Fiber Composite ◽  
Failure Process ◽  
Tensile Load ◽  
Lap Joints ◽  
Adhesive Joints ◽  
Image Correlation

Adhesive bonding technology is widely used for connecting composite pipes recent years, for the adhesive joints have many advantages such as weight reduction, ease of manufacture, and more importantly, uniform stress distribution and less stress concentration within the joint region. Nevertheless, one of the limitations of adhesive joints is the difficulty in predicting the joint strength due to the presence of defects in the adhesive due to improper curing process. This paper presents an experimental study of single-lap joints with disbond defects at the adherend-adhesive interface. Different sets of adhesively-bonded singlelap joints containing varied disbond conditions were prepared and tested. The joints used carbon fiber reinforced polymer (CFRP) laminates as substrates and epoxy resin as adhesive, with ultrathin aluminum foil (10um) as disbond defects in different sizes and locations. The full deformation fields were measured using the digital image correlation (DIC) method. The samples were subjected to tensile load till failure to determine the bond strength. Before the tensile test, the defective adhesive joints were detected by a phased-array ultrasonic instrument to identify the bond-line quality of joints. The results show that the disbond defects can be detect by ultrasonic phased-array technique, and the detriment of disbond defect to the failure process can be observed and recorded by DIC system. Based on the findings, the failure modes and failure mechanism of bonded CFRP joint were further discussed.

scholarly journals Experimental and Numerical Investigation on C/SiC Composite Z-Pinned/Bonded Hybrid Single-Lap Joints

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1130
Author(s):  
Yao Wang ◽  
Xiaodong Wang ◽  
Zhidong Guan ◽  
Jifeng Xu ◽  
Xia Guo
Keyword(s):  
Failure Mechanism ◽  
Composite Structures ◽  
Mechanical Performance ◽  
Failure Process ◽  
Three Dimensional ◽  
Discrete Distribution ◽  
Lap Joints ◽  
Single Lap Joints ◽  
Load Peak ◽  
Two Peaks

Z-pinned/bonded joints are great potential connection components that have been used in the 2D C/SiC composite structures; however, the hybrid joints present complex failure mechanism considering the secondary deposited SiC matrix in the clearance. Therefore, the mechanical performance and failure mechanism of the joints are investigated through experimental and numerical methods in this paper. Experiment results show that two peaks exist in the load–displacement curves. The first load peak is 2891–4172 N with the corresponding displacement of 0.10–0.15 mm, and the second load peak is 2670–2919 N with the corresponding displacement of 0.21–0.25 mm. Besides that, the secondary deposited SiC matrix exhibits discrete distribution, and it has significant effects on the failure mechanism. Validated by experimental data, the proposed three-dimensional numerical model based on modified Hashin’s criterion and fastener element can predict the mechanical performance and failure process. The numerical results indicate that the first load peak is dominated by the deposited SiC matrix near the edge, while the second peak is dominated by the z-pin and the SiC matrix near the z-pin. Moreover, the effects of the deposited SiC matrix’s strength and distribution are discussed, which is meaningful to the optimal design of C/SiC composite z-pinned/bonded hybrid single-lap joints.

Influence of fabric architecture on crushing behavior of semi-hexagonal composite structures under axial loading

2018 ◽  
Vol 49 (2) ◽  
pp. 162-180 ◽  
Author(s):  
Zhenyu Wu ◽  
Maolin Wang ◽  
Zhiping Ying ◽  
Xiaoying Cheng ◽  
Xudong Hu
Keyword(s):  
Energy Absorption ◽  
Specific Energy ◽  
Composite Structures ◽  
Failure Modes ◽  
Mechanical Response ◽  
Mechanical Performance ◽  
Numerical Models ◽  
Woven Fabric ◽  
Buckling Mode ◽  
Specific Energy Absorption

This paper reports the mechanical response of semi-hexagonal part with three different multi-layer reinforcements. Unidirectional, plain woven and orthogonal fabric under quasi-static axial compression were considered. Meso-scale finite element numerical models with failure criterion were also established to simulate the onset and development of internal damage during the compression process. There were two different crush-failure modes occurring in the crush tests of the three different composite samples: a splaying mode for samples with unidirectional fabric, a buckling mode for samples with 3D orthogonal woven fabric and a mixture mode of both buckling and splaying for samples with the plain woven fabric. The samples reinforced by unidirectional fiber have the highest specific energy absorption and lowest peak loading, whereas the samples by 3D orthogonal fabric present the lowest specific energy absorption and highest peak loading. It was also demonstrated by a numerical model that the existence of Z-binder suppresses the delamination by restraining the expanding of warp and weft yarns. The comparison of numerical results and experimental data indicates that the structure of reinforcement has a significant role in the mechanical performance of textile composite.

scholarly journals Compression Shear Properties of Bonded–Bolted Hybrid Single-Lap Joints of C/C Composites at High Temperature

2020 ◽  
Vol 10 (3) ◽  
pp. 1054
Author(s):  
Yanfeng Zhang ◽  
Zhengong Zhou ◽  
Zhiyong Tan
Keyword(s):  
High Temperature ◽  
Failure Modes ◽  
Shear Failure ◽  
Shear Loading ◽  
Lap Joints ◽  
Failure Behavior ◽  
Displacement Curve ◽  
Analysis Model ◽  
Single Lap Joints ◽  
Hybrid Joints

Based on previous research, in this paper, the compressive shear failure behavior and mechanical properties of bonded–bolted hybrid single-lap joints of C/C composites at high temperature were studied. The compression shear test was performed on the joints at 800 °C to obtain the load–displacement curve and failure morphology. The failure modes of joints were observed by digital microscopy and scanning electron microscopy. A numerical analysis model was implemented in finite element code Abaqus/Explicit embedded with the user material subroutine (VUMAT). The numerical results were compared with the test results to verify the correctness of the model. The interrelationship of the compression shear loading mechanism and the variations in stress distribution between bonded joints and bonded–bolted hybrid joints at high temperature were explored. The progressive damage of hybrid joints and the variations in the ratio of the bolt load to the total load with displacement were obtained.

scholarly journals Influence of Interface Gap on the Stress Behaviour of Smart Single Lap Joints Under Time Harmonic Load

2017 ◽  
Vol 47 (2) ◽  
pp. 83-99 ◽  
Author(s):  
Jordanka Ivanova ◽  
Varbinka Valeva
Keyword(s):  
Electric Fields ◽  
Composite Structures ◽  
Mechanical Performance ◽  
Closed Form Solution ◽  
Thermal Characteristics ◽  
Lap Joints ◽  
Form Solution ◽  
Harmonic Load ◽  
Time Harmonic ◽  
Stress Behaviour

AbstractAdhesive joints are frequently used in different composite structures due to their improved mechanical performance and better understanding of the failure mechanics. The application of such structures can be seen in aerospace and high technology components. The authors developed and applied modified shear lag analysis to investigate the hygrothermalpiezoelectric response of a smart single lap joint at environmental conditions (with/without an interface gap along the overlap zone) and under dynamic time harmonic mechanical and electric loads. The main key is the study of the appearance of possible delamination along the interface. As illustrative examples, the analytical closed form solution of the structure shear and the axial stresses response, as well as the interface debond length, including influence of mechanical, piezoelectric, thermal characteristics and frequencies is performed and discussed. All results are presented in figures. The comparison of the shear stress and electric fields for both cases of overlap zone (continuous or with a gap) is also shown in figures and discussed.

Bearing strength and failure analysis on the interference-fit double shear-lap pin-loaded composite

2016 ◽  
Vol 27 (2) ◽  
pp. 179-200 ◽  
Author(s):  
Peng Zou ◽  
Kaifu Zhang ◽  
Yuan Li ◽  
Ping Liu ◽  
Huanhuan Xie
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Progressive Failure ◽  
Tensile Load ◽  
Failure Criteria ◽  
Displacement Curve ◽  
Progressive Damage ◽  
Interference Fit ◽  
Bearing Strength ◽  
Load Displacement

Interference-fit technology has a wide effect on the strength and fatigue life of composite structures. The damage around the hole may accelerate the structure failure. In this paper, a progressive damage model is developed to predict the response of interference-fit pin-loaded composite laminates during the installation and loading process with the ABAQUS subroutine user-define-field (USDFLD). The model takes contact at the pin–hole interface, the nonlinear shear stress–strain relationship and the property progressive damage into consideration. The loading procedure is separated into two parts: (a) installing the Hi-Lok pin. (b) Applying the tensile load. To predict progressive failure, the mixed failure criteria combining Hashin criteria and the maximum stress failure criteria, and the Camanho and Matthews degradation rules are conducted. The insertion load, stress and damage around the hole, load–displacement curve, and the bearing strength are predicted. A series of experiments have also been performed and the rationality of the model is testified. The parametric study is also made to analyze the effect of fit conditions on insertion load, damage, and load–displacement curve.

Assessments on the mechanical behaviour of a monolithic composite structure instrumented with a monitoring patch

2017 ◽  
Vol 51 (26) ◽  
pp. 3597-3610 ◽  
Author(s):  
Mauricio Torres ◽  
Francis Collombet ◽  
Bernard Douchin ◽  
Laurent Crouzeix ◽  
Yves-Henri Grunevald
Keyword(s):  
Finite Element ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Composite Structures ◽  
Composite Plate ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Element Model ◽  
Numerical Approach ◽  
Image Correlation

In this paper, the monitoring patch is evaluated as an alternative instrumentation technique for aircraft-type composite structures, by means of the Multi-Instrumented Technological Evaluator. In this case, the goal is to evaluate the strength and failure modes of a carbon-epoxy composite plate with two drop-offs instrumented with a monitoring patch. With the aid of finite element models, the testing of the plate under combined loads is analysed to have a first numerical approach of its behaviour. Then, the experimental campaign is accomplished by testing the plate with multi-instrumentation devices and techniques such as strain gauges and digital image correlation. A correct calculation/test correlation is achieved by comparing the strain values calculated by the finite element model and the experimental strain data acquired by gauges and digital image correlation. The results confronted provide a first evidence to quantify the influence of the monitoring patch on the mechanical performance of the composite plate. Therefore, it could be employed in the near future as instrumentation technique on large composite structures.

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