Numerical and digital image correlation analysis of tensile behavior of thin-ply hybrid laminates with discontinuous carbon sandwiched by continuous glass and carbon

Thin-ply hybrid laminates of glass and carbon fibers have been widely adopted in engineering pseudo-ductility. In this study, a Finite Element model is proposed using Abaqus to predict pseudo-ductility in thin-ply laminates consisting of three materials. These materials comprise continuous carbon (CC) and continuous glass sandwiching partial discontinuous carbon (DC). The model adopts the Hashin criterion for damage initiation in the fibers and the mixed-mode Benzeggagh-Kenane criterion on cohesive surfaces for delamination initiation and propagation. Numerically predicted stress–strain results are verified with experimental results under tensile loading. Results show pseudo-ductility increases with the increase in DC layers, and pseudo-yield strength and strain increase with the increase in CC layers. 3D-Digital Image Correlation results indicate delamination growth on pseudo-ductile laminates, and the calculated Poisson’s ratios show pseudo-ductility occurs below 0.27. Moreover, Poisson’s ratio decreases with an increase in pseudo-ductility.

Effects of environmental conditions on the axial tension–compression fatigue behavior of carbon/epoxy plain-weave laminates containing flaws

The objective of this work is to investigate the effects of environmental conditions on the axial fatigue behavior of a carbon/epoxy plain-weave laminate with an embedded flaw subjected to a partially reversed cyclic load (stress ratio R = −0.1) in tension–compression. This specific material is more commonly used in aerospace engineering for the manufacturing of aircraft structural parts, which are directly exposed to various environmental conditions during service. Specific environmental and loading conditions that are appropriate to simulate real-life conditions are considered to observe and collect information about the material's behavior. For the investigation, dry and wet coupons were submitted to room temperature, 82 and 121 ℃ under loading frequencies of 7 and 15 Hz. A maximum allowable strain increase criterion is used to monitor the flaw growth threshold or delamination onset, during fatigue testing. The ultrasonic imaging (C-scan) technique is used to verify and confirm the delamination onset. Results show that the delamination onset strain increase criterion, along with fatigue life, generally decreased as the operating temperature and humidity were increased and that frequency had little effect on the delamination onset fatigue life. The S– N curves obtained from the tension–compression fatigue data were then compared to those of a previous work carried out in tension–tension fatigue loading. Results show a clear degradation in the delamination onset fatigue life of the coupons tested under tension–tension cyclic loading when the minimum tensile component of the cyclic load was replaced with a compressive load of the same magnitude.

Analytical and Numerical Analysis Comparison of Equal Channel Angular Pressing for Al5083 Alloy

In this study, the equal channel angular pressing (ECAP) process was modeled by using computeraided design software. Then, it was numerically analyzed by the help of specific finite element analysis (FEA) software. Therefore, effective strain increase in each step of the four passing was obtained. Besides this, the strain increase also was calculated for every step of passing by using the analytical method, and the results of the methods were compared. Moreover, the required load for each passing was determined and the increase of it with the increase of passing was presented.

Conclusive Research Design and Development of the Effect of Linear Deformation on Some Debye Properties of Metals

This Work, Debye Temperature And Debye Frequency Of Metals Were Computed And Studied Using Quantum Einstein Theory. The Electron Density Parameters Of Strained Metals Is Obtained And Used In The Computation.. The Results Obtained Revealed That There Is Agreement Between The Computed And Experimental Values Of Debye Temperature And Debye Frequency. This Shows That The Model Can Be Used To Study Debye Properties Of Metals. The Debye Temperature And Debye Frequency Obtained Are More Concentrated In The High Density Limit. This Revealed That Debye Temperature And Debye Frequency Of Metals Depend On The Electronic Concentration. Also, The Experimental Value Of Debye Temperature And Debye Frequency Is Higher Than The Computed Value, This Is Because Of Some Factor Which Debye Temperature And Debye Frequency Relied On That The Theory Failed To Account For. Debye Temperature And Debye Frequency Of Metals Reduces As Strain Increase. This Shows That As Strain Increase, Space Between Lattice Atom Increase Which Reduces Strength Of Electron Interaction And There-By Forces Debye Temperature, Debye Frequency To Decrease As Deformation Increase. This Behavior Of Metals Reveal That Debye Temperature And Debye Frequency Is Greatly Affected By Deformation.

Thermo-Mechanical Reliability of 1200V-450A IGBT Module Considering Voids in the Solder Layer

1200V-450A IGBT power modules are fabricated in this paper. We study both the steady state and transient thermal performance of the IGBT assemblies by the finite element method using commercial software ANSYS Workbench to better understand the characteristic. Furthermore, power cycling tests indicate that inelastic strain increase as the numbers of cycles increase. In addition, X-ray photographs and ultrasound scan images were compared before and after the experiment. The thrust force of bonding wires decrease with increasing numbers of cycles, as indicated by tested.