scholarly journals Influence of Preload on Failure Modes of Hybrid Metal-Composite Protruding Bolted Joints

2021 ◽  
Vol 13 (1) ◽  
pp. 29-41
Author(s):  
Calin-Dumitru COMAN
Keyword(s):  
Failure Modes ◽  
Material Model ◽  
Element Model ◽  
Damage Mechanism ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Metal Composite ◽  
Damage Initiation ◽  
Failure Propagation ◽  
Nonlinear Shear

This paper presents the effects of torque preload on the damage initiation and growth in the CFRP (Carbon Fiber Reinforced Polymer) composite laminated adherent of the single-lap, single-bolt, hybrid metal-composite joints. A detailed 3D finite element model incorporating geometric, material and friction-based contact full nonlinearities is developed to numerically investigate the preload effects on the progressive damage analysis (PDA) of the orthotropic material model. The PDA material model integrates the nonlinear shear response, Hashin-tape failure criteria and strain-based continuum elastic properties degradation laws being developed using the UMAT user subroutine in Nastran commercial software. In order to validate the preload effects on the failure modes of the joints with hexagonal head bolts, experiments were conducted using the SHM (Structural Health Monitoring) technique. The results showed that the adherent torque level is an important parameter in the design process of an adequate bolted joint and its effects on damage initiation and failure modes were quite accurately predicted by the PDA material model, which proved to be computational efficient and can predict failure propagation and damage mechanism in hybrid metal-composite bolted joints.

Preload Effects on Failure Mechanisms of Hybrid Metal-Composite Bolted Joints

2019 ◽  
Vol 957 ◽  
pp. 293-302
Author(s):  
Calin Dumitru Coman ◽  
Dan Mihai Constantinescu
Keyword(s):  
Failure Modes ◽  
Material Model ◽  
Element Model ◽  
Damage Mechanism ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Metal Composite ◽  
Damage Initiation ◽  
Failure Propagation ◽  
Nonlinear Shear

This paper presents the effects of torque preload on the damage initiation and growth in the CFRP (Carbon Fiber Reinforced Polymer) composite laminated adherent of the single-lap, single-bolt, hybrid metal-composite joints. A detailed 3D finite element model incorporating geometric, material and friction-based contact full nonlinearities is developed to numerically investigate the preload effects on the progressive damage analysis (PDA) of the orthotropic material model. The PDA material model integrates the nonlinear shear response, Hashin-tape failure criteria and strain-based continuum elastic properties degradation laws being developed using the UMAT user subroutine in Nastran commercial software. In order to validate the preload effects on the failure modes of the joints with hexagonal head bolts, experiments were conducted using the SHM (Structural Health Monitoring) technique. The results showed that the adherent torque level is an important parameter in the design process of an adequate bolted joint and its effects on damage initiation and failure modes were quite accurately predicted by the PDA material model, which proved to be computational efficient and can predict failure propagation and damage mechanism in hybrid metal-composite bolted joints.

scholarly journals Influence of Geometry on Failure Modes of Hybrid Metal-Composite Protruding Bolted Joints

2021 ◽  
Vol 13 (3) ◽  
pp. 29-44
Author(s):  
Calin-Dumitru COMAN
Keyword(s):  
Failure Modes ◽  
Material Model ◽  
Element Model ◽  
Damage Mechanism ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Metal Composite ◽  
Damage Initiation ◽  
Failure Propagation ◽  
Geometry Effects

This article presents the influence of joint geometry on the damage mode in the CFRP (Carbon Fiber Reinforced Polymer) composite plate of the single-lap, protruding, hybrid metal-composite joints. A detailed 3D finite element model incorporating geometric, material and friction-based contact full nonlinearities is developed to numerically investigate the geometry effects on the progressive damage analysis (PDA) of the orthotropic material model. The PDA material model integrates the nonlinear shear response, Hashin-tape failure criteria and strain-based continuum degradation rules being developed using the UMAT user subroutine in Nastran commercial software. In order to validate the geometry effects on the failure modes of the joints with hexagonal head bolts, experiments were conducted using the SHM (Structural Health Monitoring) technique. The results showed that the plate geometry is an important parameter in the design process of an adequate bolted joint and its effects on damage initiation and failure modes were quite accurately predicted by the PDA material model, which proved to be computational efficient and can predict failure propagation and damage mechanism in hybrid metal-composite bolted joints.

scholarly journals The Influence of Temperature on the Strength of Hybrid Metal-Composite Multi-Bolts Joints

2020 ◽  
Vol 12 (3) ◽  
pp. 49-64
Author(s):  
Calin-Dumitru COMAN
Keyword(s):  
Temperature Effects ◽  
Failure Modes ◽  
Material Model ◽  
Element Model ◽  
Damage Mechanism ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Metal Composite ◽  
Damage Initiation ◽  
Nonlinear Shear

This paper presents the temperature influence on the strength of the hybrid metal-composite multi-bolted joints. A detailed 3D finite element model, incorporating all possible nonlinearities as large deformations, in plane nonlinear shear deformations, elastic properties degradation of the composite material and friction-based full contact, is developed to anticipate the temperature changing effects on the progressive damage analysis (PDA) at lamina level and failure modes of metal-composite multi-bolted joints. The PDA material model accounts for lamina nonlinear shear deformation, Hashin-type failure criteria and strain-based continuum degradation rules being developed using the UMAT user subroutine in Nastran commercial software. In order to validate the temperature effects on the failure modes of the joint with protruding and countersunk bolts, experiments were conducted using the SHM (Structural Health Monitoring) technique in the temperature controlled chamber. The results showed that the temperature effects on damage initiation and failure modes have to be taken into account in the design process in order to fructify the high specific strength of the composites. Experimental results were quite accurately predicted by the PDA material model, which proved to be computational efficient and can predict failure propagation and damage mechanism in hybrid metal-composite multi-bolted joints.

scholarly journals The Influence of Geometry on Failure Modes of Countersunk Bolted Hybrid Joints

2020 ◽  
Vol 12 (2) ◽  
pp. 19-34
Author(s):  
Calin-Dumitru COMAN
Keyword(s):  
Failure Modes ◽  
Numerical Study ◽  
Material Model ◽  
Element Model ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Metal Composite ◽  
Damage Initiation ◽  
Geometry Parameter ◽  
Nonlinear Shear

This paper presents a numerical study for the influence of geometry on the damage initiation and growth in the CFRP (Carbon Fiber Reinforced Polymer) laminated plate of the hybrid metal-composite countersunk bolted joints. A detailed 3D finite element model incorporating material and friction-based contact full nonlinearities is developed to investigate the geometry effects on the failure modes of the hybrid metal-composite bolted joints. The material model for CFRP joint counterpart integrates nonlinear shear response for unidirectional laminae, Hashin-type failure criteria and strain-based continuum degradation rules which were developed using the UMAT user subroutine in MSC. Patran-Nastran (MSC. Software Corporation Inc.) commercial software. Experiments were conducted in order to validate the nonlinear progressive damage analysis (PDA) results on the failure modes of the joints with countersunk bolts. The numerical and experimental results showed that the joint geometry parameter defined by the ratio between the plates width and hole diameter has an important influence in designing phase of a reliable bolted joint and its effects on damage initiation and failure modes were quite accurately predicted by the numerical model, which proved to be computational efficient and could predict damage mechanisms in hybrid metal-composite countersunk bolted joints.

scholarly journals Temperature Effects on Damage Mechanisms of Hybrid Metal – Composite Bolted Joints Using SHM Testing Method

2019 ◽  
Vol 11 (1) ◽  
pp. 61-67
Author(s):  
Calin-Dumitru COMAN ◽  
Ion DIMA ◽  
Stefan HOTHAZIE ◽  
George PELIN ◽  
Tiberiu SALAORU
Keyword(s):  
Temperature Effects ◽  
Failure Modes ◽  
Damage Mechanism ◽  
Failure Criteria ◽  
Bolted Joints ◽  
Fracture Mechanisms ◽  
Progressive Damage ◽  
Metal Composite ◽  
3D Fem ◽  
Damage Mechanisms

This paper presents the quasi-static thermo-mechanical loading effects on the progressive damage mechanisms and failure modes of the single-bolt, single-shear, hybrid metal-composite, bolted joints in aerospace applications. A three-dimensional finite element method (FEM) technique was used to model the countersunk head bolted joint in details, including geometric and frictional based contact full nonlinearities and using commercial software PATRAN as pre/post-processor. The progressive damage analysis (PDA) in laminated (CFRP/ vinyl ester epoxy) composite material including nonlinear shear behavior, Hashin-type failure criteria and strain-based continuous degradation rules for different values of temperatures was made using SOL 400 NASTRAN solver. In order to validate the numerical results and close investigation of the fracture mechanisms for metal-composite bolted joints by determining ultimate failure loads, experiments were conducted in temperature controlled chamber using SHM (Structural Health Monitoring) technique. The results show that the thermal effects are not negligible on failure mechanism in hybrid aluminum-CFRP bolted joints having strong different thermal expansion coefficients. The complex 3D FEM model using advanced linear continuum solid-shell elements proved computational efficiency and ability to accurately predict the various failure modes as bearing and shear-shear out, including the temperature effects on the failure propagation and damage mechanism of hybrid metal-composite bolted joints.

Temperature effects on joint strength and failure modes of hybrid aluminum–composite countersunk bolted joints

2019 ◽  
Vol 233 (11) ◽  
pp. 2204-2218 ◽  
Author(s):  
Calin-Dumitru Coman ◽  
Dan Mihai Constantinescu
Keyword(s):  
Temperature Effects ◽  
Failure Modes ◽  
Testing Machine ◽  
Material Model ◽  
Bolted Joints ◽  
Progressive Damage ◽  
Damage Analysis ◽  
Bearing Failure ◽  
Aluminum Composite ◽  
Damage Initiation

This paper presents the effects of temperature on the damage initiation and growth in the carbon fiber-reinforced polymer composite laminate of a hybrid aluminum–composite countersunk bolted joints designed for the bearing failure mode. Strain gage measurements conducted using an Instron testing machine coupled to a temperature-controlled chamber together with a detailed three-dimensional finite element model incorporating geometric, material and friction-based full contact nonlinearities are used to investigate the temperature effects on the progressive damage analysis of the orthotropic material model. The progressive damage analysis material model integrates the lamina nonlinear shear deformation, Hashin-type failure criteria and strain-based continuum degradation rules, being developed using the UMAT user subroutine in the MSC Patran-Nastran (MSC Software Corporation) commercial software. The results showed that the temperature effects on damage initiation and failure modes are quite accurately predicted by the progressive damage analysis material model, which proved to be computationally efficient and therefore can predict failure propagation and damage mechanisms. A low temperature increases the limit and ultimate forces and produces net-section failure, while a high temperature favors a bearing failure and even shear-out of the composite adherend of the hybrid aluminum–composite countersunk bolted joint.

Finite Element Analysis of X-Cor Sandwich's Compressive Strength

2011 ◽  
Vol 306-307 ◽  
pp. 733-737
Author(s):  
Xu Dan Dang ◽  
Xin Li Wang ◽  
Hong Song Zhang ◽  
Jun Xiao
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Compressive Strength ◽  
Failure Modes ◽  
Failure Mechanisms ◽  
Element Model ◽  
Failure Criteria ◽  
Stiffness Degradation ◽  
Element Analysis ◽  
Finite Element Software

In this article the finite element software was used to analyse the values for compressive strength of X-cor sandwich. During the analysis, the failure criteria and materials stiffness degradation rules of failure mechanisms were proposed. The failure processes and failure modes were also clarified. In the finite element model we used the distributions of failure elements to simulate the failure processes. Meanwhile the failure mechanisms of X-cor sandwich were explained. The finite element analysis indicates that the resin regions of Z-pin tips fail firstly and the Z-pins fail secondly. The dominant failure mode is the Z-pin elastic buckling and the propagation paths of failure elements are dispersive. Through contrast the finite element values and test results are consistent well and the error range is -7.6%~9.5%. Therefore the failure criteria and stiffness degradation rules are reasonable and the model can be used to predict the compressive strength of X-cor sandwich.

Prediction of Impact Damage of Composite Laminates Using a Mixed Damage Model

2014 ◽  
Vol 513-517 ◽  
pp. 235-237
Author(s):  
Shi Yang Zhao ◽  
Pu Xue
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Impact Damage ◽  
Damage Model ◽  
Material Model ◽  
Element Model ◽  
Fiber Damage ◽  
Damage Process ◽  
Matrix Damage

In order to effectively describe the damage process of composite laminates and reduce the complexity of material model, a mixed damage model based on Linde Criteria and Hashin Criteria is proposed for prediction of impact damage in the study. The mixed damage model can predict baisc failure modes, including fiber fracture, matrix tensile damage, matrix compressive damage. Fiber damage and matrix damage in compression are described based on the progressive damage mechanics; and matrix damage in tension is described based on Continuous Damage Mechanics (CDM). Meanwhile, for interlaminar delamination, damage is described by cohesive model. A finite element model is established to analyze the damage process of composite laminate. A good agreement is got between damage predictions and experimental results.

Experimental and numerical investigation of fatigue damage accumulation in composite laminates

2015 ◽  
Vol 26 (6) ◽  
pp. 840-858 ◽  
Author(s):  
Soran Hassanifard ◽  
Mohsen Feyzi
Keyword(s):  
Fatigue Life ◽  
Composite Laminates ◽  
Failure Modes ◽  
Three Dimensional ◽  
Load Ratio ◽  
Element Model ◽  
Failure Criteria ◽  
Damage Parameter ◽  
Fatigue Damage Accumulation ◽  
Three Dimensional Finite Element

In this study, a three-dimensional finite element model was developed to predict the fatigue life of composite bolted joints. In this model, progressive damage theory was used. The fatigue characterization was based on Hashin’s failure criteria which recognize the failure modes. To decrease the number of unidirectional tests, the effects of load ratio were considered based on Kawai’s criterion. A modified form of Miner’s rule was proposed to calculate the damage parameter. This equation corrected the effects of the fatigue failure cycles and included the effects of different load ratios. Also, this model could decrease the overestimation of the fatigue life predictions. All of the formulations were combined and used in a step-by-step solution. In this respect, a new iterative algorithm was developed so that at each step of solution, the material properties of all failed layers of each element were reduced according to the failure mode and sudden degradation rules. The estimated fatigue life was compared to the experimental data, and an excellent correlation between the results was observed. This model could monitor the damage propagation in fabricated joints.

Some factors affecting the loosening failure of bolted joints under vibration using finite element analysis

2017 ◽  
Vol 232 (21) ◽  
pp. 3942-3953 ◽  
Author(s):  
Hao Gong ◽  
Jianhua Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Vibration Frequency ◽  
Plastic Material ◽  
Material Model ◽  
Element Model ◽  
Bolted Joints ◽  
Vibration Parameter ◽  
Element Analysis ◽  
Loosening Rate

Finite element analysis has been regarded as an effective research method for analyzing the loosening failure of bolted joints under vibration. However, there exist some factors, which influence the accuracy and reliability of loosening results, thus determining the explanations of the loosening mechanism. In this study, a 3D finite element model of a typical bolted joint was built to investigate the effects of several different factors on the loosening under transverse vibration loading. These influencing factors include preload generation, vibration parameter, and material model. Based on the simulation results, it was found that applying the method of pretension element to generate preload instead of the actual method of torque was reliable and efficient. For the vibration parameter, it showed that the decrease rate in preload was higher for a larger vibration amplitude. But once the bearing surface reached complete slip, the loosening rate would keep constant. This was because the thread surface at that time reached a sticking state. Vibration frequency was proved to have no effect on the loosening behavior. This result demonstrated that the quasi-static assumption for vibration frequency was reasonable. Additionally, it also indicated that plastic material models only affected the preload loss in the initial several vibration cycles and had no influence on the loosening rate of preload after several vibration cycles. Finally, experiments were conducted to confirm qualitatively the results obtained based on finite element analysis.

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