Effects of Strain Rate on the Stress Propagations in Bonded Shrink Fitted Joints Under Impact Push-Off Loadings

2011 ◽  
Author(s):  
Lijuan Liao ◽  
Toshiyuki Sawa ◽  
Takashi Kobayashi ◽  
Yasuhiro Goda
Keyword(s):  
Strain Rate ◽  
Adhesive Layer ◽  
Rate Sensitivity ◽  
Middle Part ◽  
Experimental Results ◽  
Von Mises Stress ◽  
Deformation Behaviors ◽  
Von Mises ◽  
Structural Adhesive ◽  
Good Agreement

The effects of the strain rate sensitivity on the stress propagations of bonded shrink fitted joint, in which a ring is fitted using an adhesive layer at the middle part of a shaft, subjected to impact push-off loadings are examined. The plastic flow deformation behaviors of structural adhesive under some strain rates are examined experimentally. In addition, the stress wave propagations in the joint are analyzed using finite element method (FEM). The experimental results show that the yield stress of the adhesive increases as the strain rate increases nonlinearly. It is observed that the maximum equivalent von Mises stress occurs in the adhesive layer at the upper interfaces, which causes the rupture of the joint based on the numerical calculations. Furthermore, the strain responses obtained from numerical and experimental methods are compared with each other. A fairly good agreement is obtained between FEM calculations and experiments. In addition, the joint strength is predicted by impact energy using experimental results, which is about 20.85 J in the present study.

Improvement Design of Adhesive Layer on Honeycomb Structure for Railway Vehicle System by Uniform Design Method

2020 ◽  
Vol 830 ◽  
pp. 53-58
Author(s):  
Yung Chang Cheng ◽  
Pongsathorn Pornteparak
Keyword(s):  
Design Method ◽  
Uniform Design ◽  
Equivalent Stress ◽  
Adhesive Layer ◽  
Honeycomb Structure ◽  
Von Mises Stress ◽  
Railway Vehicle ◽  
Original Design ◽  
Control Factors ◽  
Von Mises

The purpose of this paper focuses on adhesive layer strength while having a thermal cycling of honeycomb composite sandwich structure by using the uniform design of experiments method improving the von Mises stress of honeycomb structure. Three system parameters of the honeycomb structure are selected as the control factors to be improved. Uniform design of experiment is applied to create a set of simulation experiments. Applying ANSYS/Workbench software, the finite element modelling is investigated and the von Mises stress of the honeycomb structure is calculated under metal-honeycomb core flatwise tensile test. From the numerical results, the best honeycomb structure dimension of all the experiments which causes the smaller von Mises stress is selected as the improved version of design. Finally, the best model of the experiments which causes the minimum equivalent stress is regarded as the improved version of design. Compared with the original design, the result of ASTM C297 improved version is 17.386 MPa, which mean improved 36.28%, ASTM C364 improved version is 19.015 MPa, which mean improved 25.26%, ASTM C365 improved version is 16.86 MPa, which mean improved 12.35%.

Mobilization of Fully Plastic Moment Capacity for Pressurized Pipes

1999 ◽  
Vol 121 (4) ◽  
pp. 237-241 ◽  
Author(s):  
M. Mohareb ◽  
D. W. Murray
Keyword(s):  
Internal Pressure ◽  
Axial Force ◽  
Yield Criterion ◽  
Axial Loading ◽  
Experimental Results ◽  
Moment Capacity ◽  
Interaction Diagram ◽  
Von Mises ◽  
Force Pressure ◽  
Good Agreement

An analytical expression is derived for the prediction of fully plastic moment capacity of pipes subjected to axial loading and internal pressure. The expression is based on the von Mises yield criterion. The expression predicts pipe moment capacities that are in good agreement with full-scale experimental results. A universal nondimensional moment versus effective axial force-pressure interaction diagram is developed for the design of elevated pipe lines.

Study on the Super-Plastic Property of ECAPed Magmesium Alloy

2011 ◽  
Vol 311-313 ◽  
pp. 640-643
Author(s):  
Ying Jie Li ◽  
Xiu Zhi Zhang ◽  
Feng Li
Keyword(s):  
Grain Boundary ◽  
Strain Rate ◽  
Rate Sensitivity ◽  
Plastic Property ◽  
Tensile Tests ◽  
Grain Boundary Sliding ◽  
Flow Activation Energy ◽  
Super Plastic ◽  
Deformation Behaviors ◽  
Lower Temperature

In this paper, the influence of temperature and strain rate on the superplastic deformation behaviors of the Mg-Zn-Nd alloy has been investigated through performing tensile tests at different temperatures and strain rates. After 4 passes of ECAP by route C, the strain-rate sensitivity coefficients reached 0.32 at 300°C, indicating that the ECAPed Mg-Zn-Nd alloy exhibited a good superplasticity at lower temperature. The results of flow activation energy showed that the super-plastic deformation mechanism of magnesium alloys is grain-boundary sliding controlled by grain boundary diffusion.

Simulation of Fracture Behavior of Elastomer Modified Polypropylene Based on Elastoviscoplastic Constitutive Equation With Craze and Tensile Softening Law

2005 ◽  
Author(s):  
Hiroyuki Mae
Keyword(s):  
Constitutive Equation ◽  
Crack Propagation ◽  
Strain Rate ◽  
Fracture Behavior ◽  
Experimental Results ◽  
Experimental Result ◽  
Load Displacement ◽  
Macroscopic Crack ◽  
Tensile Softening ◽  
Good Agreement

The strong strain-rate dependence, neck propagation and craze evolution characterize the large plastic deformation and fracture behavior of polymer. In the latest study, Kobayashi, Tomii and Shizawa suggested the elastoviscoplastic constitutive equation based on craze evolution and annihilation and then applied it to the plane strain issue of polymer. In the previous study, the author applied their suggested elastoviscoplastic constitutive equation with craze effect to the three dimensional shell issue and then showed that the load displacement history was in good agreement with the experimental result including only microscopic crack such as craze. For the future industrial applications, the macroscopic crack had to be taken into account. For instance, an airbag deployment simulation needed the macroscopic crack prediction. Thus, the main objective of this study was to propose the tensile softening equation and then add it to the elastoviscoplastic constitutive equation with craze effect so that the load displacement history could be roughly simulated during the macroscopic crack propagation. The tested material in this study was the elastomer blended polypropylene used in the interior and exterior of automobiles. First, the material properties were obtained based on the tensile test results at wide range of strain rates: 10−4 – 102 (1/sec). Next, the fast compact tension test was conducted and then the tensile softening parameters were fixed. Then, the fast bending test and the dart impact test were carried out in order to obtain the load displacement history and also observe the macroscopic crack propagation at high strain rate. Finally, the fracture behavior was simulated and then compared with the experimental results. It was shown that the predictions of the constitutive equation with the proposed tensile softening equation were in good agreement with the experimental results.

High Strain Rate Tensile Behavior of Carbon Fiber Reinforced Aluminum Laminates

2005 ◽  
Author(s):  
Yuanxin Zhou ◽  
Pingwen Mao ◽  
Mohammad F. Uddin ◽  
Shaikh Jeelani
Keyword(s):  
Carbon Fiber ◽  
Strain Rate ◽  
Rate Sensitivity ◽  
Tensile Tests ◽  
Strain Rate Range ◽  
Fiber Reinforced ◽  
Stress Strain ◽  
Static Tensile ◽  
Carbon Fiber Reinforced ◽  
Good Agreement

In this paper, loading and loading-unloading tests of carbon fiber reinforced aluminum laminates (CRALL) have been carried out in a tensile impact apparatus, and quasi-static tensile tests have been performed on a MTS-810 machine. Complete stress-strain curves of composite in the strain rate range from 0.001–1200 1/s have been obtained. Experimental results show that CRALL composite is a strain rate sensitivity material, the tensile strength and failure strain both increased with increasing strain rate. A linear strain hardening model has been combined with Weibull distribution function to establish a constitutive equation for CRALL. The simulated stress-strain curves from model are in good agreement with the test data. The analysis of the model shows that the Weibull scale parameter, σ0, increased with increasing strain rate, but Weibull shape parameter, β, can be regarded as a constant.

Mechanical behavior of composite parts joined through different processes

2021 ◽  
Vol 63 (5) ◽  
pp. 411-419
Author(s):  
İsmail Yasin Sülü ◽  
Şemsettin Temiz
Keyword(s):  
Finite Element ◽  
Tensile Load ◽  
Adhesive Layer ◽  
Von Mises Stress ◽  
Maximum Effect ◽  
Model Design ◽  
Element Analysis ◽  
Failure Loads ◽  
Effect Parameter ◽  
Von Mises

Abstract In this research, composite parts joined according to different joining methods such as single-lap and double-lap embedded adhesive subjected to tensile load were analyzed via the 3-D finite element method (FEM). The study differed from other studies in terms of joining techniques used and the specified parameter and model design. This study aims to emphasize the advantages of joining techniques in terms of aesthetically and joining methods over each other. In the analysis, composite parts carbon/epoxy (T 700) at varied fiber orientation angles and adhesive DP 410 were used. The models for numerical analyses were created in an ANSYS 14.5 software package. Finite element analysis (FEA) was successful in predicting failure loads. Stress in the x, y, z directions, shear stress and von-Mises stress on the adhesive were obtained at the time of failure for predetermined parameters. As a result, the effects of orientation angles, overlap lengths, adhesive layer and bonding methods were investigated. The maximum effect parameter and joining technique was determined for the composite parts joined through varied joining methods.

Experimental and Physical-Based Constitutive Model Study of FCC Metal Over Wide Temperature and Strain Rate Ranges

2015 ◽  
Author(s):  
Jianchao Yu ◽  
Gang Wang ◽  
Jianwei Qin ◽  
Maobing Shuai ◽  
Yiming Rong
Keyword(s):  
Aluminum Alloy ◽  
Flow Stress ◽  
Constitutive Model ◽  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Deformation ◽  
True Strain ◽  
Experimental Results ◽  
Deformation Behaviors ◽  
Fcc Metal

Dynamic deformation behaviors of aluminum alloy Al1060 (FCC metal) are studied by the uniaxial compression tests on the Split Hopkinson Pressure Bar over wide temperature and strain rate ranges. The experimental results show that the flow stress is both strain rate and temperature sensitivity. The flow stress decreases with increasing temperature when the strain rate keeps constant. When the temperature keeps constant, the flow stress increases with increasing strain rate. Considering the thermal activation of dislocation gliding in the dynamic deformation process, a physical-based constitutive model is developed based on the experimental results to predict the flows stress of Al1060 at a given strain rate and temperature. The material constants in the constitutive model are determined by the nonlinear genetic algorithm. The true stress-true strain curves predicted by the proposed constitutive models can give good correlations with the experimental results, which confirm that the proposed physical-based constitutive can accurately characterize the dynamic deformation behaviors of the studied aluminum alloy Al1060.

Strain Rate Sensitivity of 31Mn-3Al-3Si TWIP Steel with Partially Recrystallized Fine Grained Structure

2008 ◽  
Vol 584-586 ◽  
pp. 673-678 ◽  
Author(s):  
Rintaro Ueji ◽  
Kenji Harada ◽  
Akihiko Takemura ◽  
Kazutoshi Kunishige
Keyword(s):  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Twip Steel ◽  
Volume Fraction ◽  
Tensile Deformation ◽  
Cell Structure ◽  
Rate Sensitivity ◽  
Dislocation Cell ◽  
Annealed Specimen ◽  
Deformation Behaviors

Strain rate sensitivity of the strength of TWIP (Twinning Induced Plasticity) steel with the mixture of recrystallized fine grains and rolling-deformation microstructures was studied. The 31mass%Mn-3%Al-3%Si TWIP steel sheet was severely cold-rolled to a reduction of 92% and subsequently annealed at various temperatures ranging from 600oC to 700oC in order to obtain the partial recrystallized microstructure with various fraction of recrystallized microstructure. The 600oC annealed specimen keeps similar morphologies as observed in the as-rolled structure consisting of both the fine lamellar dislocation cell structure and the twin/matrix lamellar structure; whereas, in the specimen annealed at 625oC or 675oC , the partially recrystallized fine grains (d~1µm) with a few dislocations evolve. The volume fraction of recrystallized fine grains increases with increasing of the annealing temperature while the mean diameter of the recrystallized grains is not changed largely. The tensile deformation behaviors were measured at various strain rates ranging from 10-3sec-1 to 102sec-1. The strength and elongation become smaller and larger, respectively, with increasing the fraction of the recrystallized microstructure. The activation volume of dislocations becomes larger with increasing the fraction of recrystallized microstructure.

scholarly journals Characterization of Microstructural Evolution for a Near-α Titanium Alloy with Different Initial Lamellar Microstructures

Metals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 1045 ◽  
Author(s):  
Hui Li ◽  
Zhanglong Zhao ◽  
Yongquan Ning ◽  
Hongzhen Guo ◽  
Zekun Yao
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Microstructural Evolution ◽  
Power Dissipation ◽  
Flow Instability ◽  
Lamellar Microstructure ◽  
Rate Sensitivity ◽  
Lamellar Thickness ◽  
Processing Maps ◽  
Deformation Behaviors

The effects of initial lamellar thickness on microstructural evolution and deformation behaviors of a near-α Ti-5.4Al-3.7Sn-3.3Zr-0.5Mo-0.4Si alloy were investigated during isothermal compression in α + β phase field. Special attention was paid to microstructural conversion mechanisms for α lamellae with different initial thicknesses. The deformation behaviors, including flow stress, temperature sensitivity, and strain rate sensitivity, and processing maps and their dependence on initial lamellar thickness were discussed. The detailed microstructural characterizations in different domains of the developed processing maps were analyzed. The results showed that the peak efficiency of power dissipation decreased with increasing initial lamellar thickness. The interaction effects with different extents of globularization, elongating, kinking, and phase transformation of lamellar α accounted for the variation in power dissipation. The flow instability region appeared to expand more widely for thicker initial lamellar microstructures during high strain rate deformation due to flow localization and local lamellae kinking. The electron backscatter diffraction (EBSD) analyses revealed that the collaborative mechanism of continuous dynamic recrystallization (CDRX) and discontinuous dynamic recrystallization (DDRX) promoted the rapid globularization behavior for the thinnest acicular initial microstructure, whereas in case of the initial thick lamellar microstructure, CDRX leading to the fragmentation of lamellae was the dominant mechanism throughout the deformation process.

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