scholarly journals Effects of Hole Perpendicularity Error on Mechanical Performance of Single-Lap Double-Bolt Composite Joints

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Xueshu Liu ◽  
Yuxing Yang ◽  
Yiqi Wang ◽  
Yongjie Bao ◽  
Hang Gao
Keyword(s):  
Failure Modes ◽  
Mechanical Performance ◽  
Damage Model ◽  
Composite Joints ◽  
Load Path ◽  
Direct Function ◽  
Tilting Angle ◽  
Static Tensile ◽  
Progressive Damage Model ◽  
Good Agreement

Static tensile experiments and numerical simulations were carried out to study effects of hole perpendicularity error on mechanical performance of single-lap double-bolt composite joints. Hole tilting angle, varying from 1 to 4 degrees, and hole tilting direction to account for anisotropic properties of composite material were investigated. Progressive damage model (PDM) based on Chang-Lessard type criterion with an extension by Olmedo was created, which involved seven failure modes and made material properties be a direct function of predefined field variables. The model was implemented in ABAQUS/Standard using a UMAT subroutine. Good agreement was found when comparing numerical simulation results with experimental outcomes. In addition, the results demonstrate that, with increasing of hole tilting angle, damage is prone to arise and the load path of the composite bolted joints alters with changing of hole tilting direction, which result in severe stress concentration around the edge of hole and joint failure in advance.

Numerical Characteristic Length Model for Mechanical Composite Joints in Mechanical Manufacturing Engineering

2014 ◽  
Vol 910 ◽  
pp. 308-311
Author(s):  
Zhi Xiang Xu
Keyword(s):  
Characteristic Length ◽  
Damage Model ◽  
Numerical Characteristic ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Composite Joints ◽  
Static Tensile ◽  
Failure Loads ◽  
Ultimate Failure ◽  
Progressive Damage Model

According to the progressive damage analysis based numerical characteristic length scheme presented by Zhang, a progressive damage model established by Liu is adopted here to calculate characteristic lengths for mechanical composite joints. Four groups of specimens with different lay-ups and geometries were designed and fabricated and static tensile experiments were carried out to verify the suitability of the numerical characteristic length model. Good agreements between the predicted ultimate failure loads of the specimens and experimental outcomes are obtained. In addition, the characteristic lengths calculated from the experimental ultimate failure loads are in accordance with that obtained from numerical ultimate failure loads, which give evidence of the feasibility and suitability of the numerical characteristic length model.

Progressive damage characteristics of screwed single-lap CFRPI-metal joint subjected to tensile loading at RT and 350°C

2021 ◽  
pp. 002199832098559
Author(s):  
Yun-Tao Zhu ◽  
Jun-Jiang Xiong ◽  
Chu-Yang Luo ◽  
Yi-Sen Du
Keyword(s):  
Damage Model ◽  
Tensile Loading ◽  
Tensile Tests ◽  
Displacement Curve ◽  
Progressive Damage ◽  
Damage Characteristics ◽  
Metal Joint ◽  
Static Tensile ◽  
Strength And Stiffness ◽  
Progressive Damage Model

This paper outlines progressive damage characteristics of screwed single-lap CFRPI-metal joints subjected to tensile loading at RT (room temperature) and 350°C. Quasi-static tensile tests were performed on screwed single-lap CCF300/AC721-30CrMnSiA joint at RT and 350°C, and the load versus displacement curve, strength and stiffness of joint were gauged and discussed. With due consideration of thermal-mechanical interaction and complex failure mechanism, a modified progressive damage model (PDM) based on the mixed failure criterion was devised to simulate progressive damage characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint, and simulations correlate well with experiments. By using the PDM, the effects of geometry dimensions on mechanical characteristics of screwed single-lap CCF300/AC721-30CrMnSiA joint were analyzed and discussed.

A progressive damage model for 3D woven composites under compression

2018 ◽  
Vol 28 (6) ◽  
pp. 857-876 ◽  
Author(s):  
Huaiyu Lu ◽  
Licheng Guo ◽  
Gang Liu ◽  
Li Zhang
Keyword(s):  
Failure Modes ◽  
Damage Model ◽  
Woven Composites ◽  
Progressive Damage ◽  
Misalignment Angle ◽  
Woven Composite ◽  
Damage Initiation ◽  
3D Woven Composites ◽  
Progressive Damage Model ◽  
Transverse Failure

A progressive damage model is proposed to investigate the damage initiation and evolution of 3D woven composites under uniaxial compression at a micromechanical level. The typical compressive experiments were carried out. Based on the observations, the compression failure modes of 3D woven composites mainly include fiber kinking, transverse failure of fiber tow, matrix fracture, and interfacial debonding. The initial damage criteria are according to the physically based failure criteria for the fiber kinking, the Puck criteria for the transverse failure of fiber tow, and the maximum stress criterion for the matrix. The damage of fiber tow–matrix interfacial is simulated through cohesive contact. Particularly, the fiber’s initial misalignment angle is taken into account in the damage model. The simulated compression results agree well with the experimental ones. The compressive stress–strain response of the 3D woven composite is forecasted. The damage evolution of each constituent of the 3D woven composite is obtained. The results show that the influence of the fiber’s initial misalignment angle on the compression strength of the 3D woven composite needs to be considered.

Modeling the Damage Progression in the Composite Structure Subjected to Static Contact Crush

2006 ◽  
Vol 324-325 ◽  
pp. 831-834
Author(s):  
Yun Peng Jiang ◽  
Wan Lin Guo
Keyword(s):  
Composite Structure ◽  
Damage Model ◽  
Damage Distribution ◽  
User Subroutine ◽  
Commercial Code ◽  
Static Contact ◽  
Laminate Theory ◽  
Damage Processes ◽  
Progressive Damage Model ◽  
Good Agreement

Based on the classic laminate theory, a progressive damage model has been incorporated into the composite structure analysis by using a commercial code, ABAQUS, via one of its user-defined subroutine, UGENS. The developed user subroutine can be applied to simulate fiber and matrix damage processes in the general composites structures. The responses of flat laminate subjected to static contact crush have been studied to verify the efficiency of the presented damage method. The predicted load-displacement relationships, damage distribution were obtained and compared with the corresponding experiments, and the results were found to be in good agreement.

Assessment of the load carrying performance of composite cross joints

2019 ◽  
Vol 54 (11) ◽  
pp. 1431-1439
Author(s):  
Liyang Liu ◽  
Mengfei Cai ◽  
Xiaoliang Geng ◽  
Peiyan Wang ◽  
Zhufeng Yue
Keyword(s):  
Damage Model ◽  
Bending Moment ◽  
Comparative Assessment ◽  
Progressive Damage ◽  
Bending Tests ◽  
Air Inlet ◽  
Four Point Bending ◽  
Load Carrying ◽  
Progressive Damage Model ◽  
Good Agreement

Composite cross joints are common structures in an airframe. When this type of joint is used on an air inlet stiffened structure, it will undertake large bending moment, especially under overpressure of the engine. In this paper, two types of cross joints are tested experimentally and simulated to investigate the load bearing characteristics and make comparative remarks. Four-point bending tests are conducted and the load deflection curves are obtained; besides, the damage pattern of the joints is reported. Based on composite progressive damage model, the numerical simulations have a good agreement with experimental results, revealing the joint failure mechanism and fastener force feature of various joints. The comparative assessment of two types of joints is summarized.

scholarly journals Microstructure and Mechanical Performance of Resistance Spot Welded Martensitic Advanced High Strength Steel

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1021
Author(s):  
Yunzhao Li ◽  
Huaping Tang ◽  
Ruilin Lai
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Mechanical Performance ◽  
Strong Dependence ◽  
High Strength ◽  
Weld Nugget ◽  
Resistance Spot ◽  
Pull Out ◽  
Cross Tension ◽  
Spot Welded

Resistance spot welded 1.2 mm (t)-thick 1400 MPa martensitic steel (MS1400) samples are fabricated and their microstructure, mechanical properties are investigated thoroughly. The mechanical performance and failure modes exhibit a strong dependence on weld-nugget size. The pull-out failure mode for MS1400 steel resistance spot welds does not follow the conventional weld-nugget size recommendation criteria of 4t0.5. Significant softening was observed due to dual phase microstructure of ferrite and martensite in the inter-critical heat affected zone (HAZ) and tempered martensite (TM) structure in sub-critical HAZ. However, the upper-critical HAZ exhibits obvious higher hardness than the nugget zone (NZ). In addition, the mechanical properties show that the cross-tension strength (CTS) is about one quarter of the tension-shear strength (TSS) of MS1400 weld joints, whilst the absorbed energy of cross-tension and tension-shear are almost identical.

Analysis of thermo-mechanical coupling damage behavior in long-term performance of microelectromechanical systems actuators

2021 ◽  
pp. 105678952110339
Author(s):  
Jiaxing Cheng ◽  
Zhaoxia Li
Keyword(s):  
Damage Mechanics ◽  
Microelectromechanical Systems ◽  
Mechanical Performance ◽  
Damage Model ◽  
Irreversible Damage ◽  
Damage Behavior ◽  
Thermal Actuators ◽  
Long Term Performance ◽  
Term Performance

Effective numerical analysis is significant for the optimal design and reliability evaluation of MEMS, but the complexity of multi-physical field couplings and irreversible damage accumulation in long-term performance make the analysis difficult. In the present paper, the continuum damage mechanics method is used to develop a creep damage model and conduct long-term performance analysis for MEMS thermal actuators with coupled thermo-mechanical damage behavior. The developed damage model can make a connection between the material deterioration due to microstructure changes and the macroscopic responses (the change of thermo-mechanical performance or structure failure). The numerical simulations of coupled thermo-mechanical behavior in long-term performance are implemented using the finite element method, which is validated through comparison with previous literature. The numerical results demonstrate that the proposed damage model and numerical method can provide effective assessment in the long-term performance of MEMS thermal actuators.

A progressive damage model for three-dimensional woven composites under ballistic impact loading

2019 ◽  
Vol 1 (1) ◽  
pp. 015028
Author(s):  
Yongqi Yang ◽  
Li Zhang ◽  
Licheng Guo ◽  
Suyang Zhong ◽  
Jiuzhou Zhao ◽  
...  
Keyword(s):  
Impact Loading ◽  
Damage Model ◽  
Three Dimensional ◽  
Ballistic Impact ◽  
Woven Composites ◽  
Progressive Damage ◽  
Progressive Damage Model

Numerical Simulation of Ring-Shape Rock Failure under Compressive Loading

2011 ◽  
Vol 378-379 ◽  
pp. 15-18
Author(s):  
Yong Bin Zhang ◽  
Zheng Zhao Liang ◽  
Shi Bin Tang ◽  
Jing Hui Jia
Keyword(s):  
Numerical Simulation ◽  
Fracture Process ◽  
Failure Modes ◽  
Failure Process ◽  
Compressive Loading ◽  
Orientation Angle ◽  
Crack Orientation ◽  
Ring Specimen ◽  
Ring Shape ◽  
Good Agreement

In this paper, a ring shaped numerical specimen is used to studying the failure process in brittle materials. The ring specimen is subjected to a compressive diametral load and contains two angled central cracks. Numerical modeling in this study is performed. It is shown that the obtained numerical results are in a very good agreement with the experiments. Effect of the crack orientation angle on the failure modes and loading-displace responses is discussed. In the range of 0°~40°, the fracture paths are curvilinear forms starting from the tip of pre-existing cracks and grow towards the loading points. For the crack orientation angle 90°, vertical fractures will split the specimen and the horizontal cracks do not influence the fracture process.

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