scholarly journals Analysis of Fracture Behaviour of Exploded Metal Cylinders with Varied Charge

2018 ◽  
Vol 183 ◽  
pp. 01036 ◽  
Author(s):  
Xinlong Dong ◽  
Xinlu Yu ◽  
Shunjie Pan
Keyword(s):  
Shock Wave ◽  
Shear Stress ◽  
Shear Fracture ◽  
Maximum Shear Stress ◽  
Equivalent Plastic Strain ◽  
Outer Wall ◽  
Detonation Pressure ◽  
Element Analysis ◽  
Free Expansion ◽  
Metal Cylinder

Explosively driven fragmentation of ductile metals cylinders is a highly complex phenomenon. In this work, the fracture characteristics of exploded TA2 titanium alloy cylinder with varied charge were investigated numerically and experimentally. The results show that the fracture surfaces of fragments lie along planes of maximum shear stress for either a higher or a lower detonation pressure, but their mechanism is different. The finite element analysis demonstrated that the equivalent plastic strain in the middle of the wall is always larger than that of inner and outer wall for metal cylinder during the stage of shock wave driven period. For the high explosive pressures, the micro-cracks originated firstly in middle zone of wall during the stage of shock wave driven, and extend to the inner and outer wall in the direction of maximum shear stress. Explosives which generate lower detonation pressures, the shear fracture of cylinder originated from the inner wall and propagate to the outer wall in an angle of 45° or 135° to radial, the crack begin at the stage of free expansion. The simulated analysis of the process of deformation and fragmentation for exploded metal cylinder agree with the experimental results.

Investigation of Design Parameters and Failure Criteria of O-Ring Seal Structure

2005 ◽  
Author(s):  
Dianyin Hu ◽  
Rongqiao Wang ◽  
Quanbin Ren ◽  
Jie Hong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Normal Stress ◽  
Maximum Shear Stress ◽  
Design Parameters ◽  
Element Analysis ◽  
Axisymmetric Model ◽  
Sealing Performance ◽  
Maximum Contact

First, this paper established the seal structural 2D axisymmetric model of a certain Solid Rocket Booster (SRB) and calculated the deformation and stresses at ignition through a large displacement, incompressible, contact finite element analysis. The results show that the maximum contact stress appears at the contact area and the maximum shear stress at groove notch. Then, some typical parameters of the seal structure which might have the impact on the sealing performance, such as the gap breadth, initial compressibility, fillets of the groove notch and bottom, groove width, were analyzed. We can find that the gap breadth and initial compressibility do great contributions to the maximum contact normal stress, and the groove notch and bottom fillets act upon the maximum shear stress obviously. In order to verify the validity of the 2D axisymmetric model, 3D structural finite element analysis of the structure was conducted, and the results indicate that in service, the upper flange is inclined relative to the nether flange, which seems to mean that the gap breadth can not be considered as a constant during the 2D axisymmetric analysis. However further calculations say that if using the minimum gap breadth gotten in 3D analysis as its constant gap value, the above 2D axisymmetric model can rationally take the place of 3D model to analyze the sealing performance. Finally, the failure modes & criteria of the O-ring seals based on the maximum contact normal stress and shear stress were determined to ensure the reliability of this structure.

Discussions on Fracture Factors of Brittle Materials under the Shear-Compression Condition

2011 ◽  
Vol 250-253 ◽  
pp. 90-94
Author(s):  
Zhi Hui Li ◽  
Jun Ping Shi ◽  
An Min Tang
Keyword(s):  
Shear Stress ◽  
Stress State ◽  
Uniaxial Compression ◽  
Frictional Force ◽  
Shear Fracture ◽  
Maximum Shear Stress ◽  
Brittle Materials ◽  
Fracture Mechanisms ◽  
Initiation Point ◽  
Fracture Angle

Based on fundamental ideas in tribology and basic concept of stress state in solid mechanics, the existence of frictional force on shear plane is discussed under uniaxial compression of brittle materials. On account of macroscopic fracture forms and mesoscopic fracture mechanisms, the key factors influencing shear fracture angle are analyzed. The results show that, when brittle materials are compressed and shear fracture occurs, shear fracture surface at the crack initiation point is consistent with the maximum shear stress. But the reason of shear fracture angle examined in experiment greater than 45º lies in that, the existence of frictional force between endface of specimen and pressure head of testing machine, and additional tensile stress produced in the materials when harder crystalline grain wedge in softer medium have changed original uniaxial compression stress state and the direction of maximum shear stress on next fracture path.

Effect of Off-Axis Cell Orientation in Smooth Muscle Tissue

2003 ◽  
Author(s):  
P. A. Sarma ◽  
Ramana M. Pidaparti ◽  
Richard A. Meiss
Keyword(s):  
Shear Stress ◽  
Smooth Muscle ◽  
Muscle Tissue ◽  
Maximum Shear Stress ◽  
Tracheal Smooth Muscle ◽  
Cell Alignment ◽  
Cell Orientation ◽  
Element Analysis ◽  
Smooth Muscle Tissue ◽  
Axis Orientation

The cell alignment in a smooth muscle tissue plays a significant role in determining its mechanical properties. In addition to shortening strain, the off-axis cell orientation θ also modify the shear stress relationship significantly. A simulation model based on finite element analysis is developed to study the effect of stresses of tracheal smooth muscle tissue when its cells are orientated off-axially. Results obtained indicate that the maximum shear stress values of tracheal smooth muscle tissue at 45% strain are 2.5 times the values at 20% strain for all three off-axis orientation values θ = 15°, 30° and 45°.

Effect of Parameters on Strength of Composites Single-Lap Adhesive Joints

2012 ◽  
Vol 490-495 ◽  
pp. 2250-2253
Author(s):  
Yin Huan Yang
Keyword(s):  
Finite Element ◽  
Shear Stress ◽  
Numerical Study ◽  
Maximum Shear Stress ◽  
Adhesive Layer ◽  
Adhesive Joints ◽  
Element Analysis ◽  
Adhesive Thickness ◽  
The Times ◽  
Peel Stress

Based on popular and maturate application of the finite element analysis method, a numerical study is presented for effect of parameters, that are composed of lap length, adhesive thickness and ply styles of adherend, on maximum peel/shear stress of T700/EXOPY composite single-lap adhesive joints in this paper. Finite element simulations are carried out to analyze the peel/shear stress fields along the interfaces between the adhesive and the adherends. The simulation results show that the joint maximum peel/shear stress decreases with increasing the lap length, and peel stress of the joint of adherends of ply style [0/90/±45/0]S is much less, and the maximum shear stress in the interfaces between the adhesive layer and the adherends do not dcreases all the times with increasing the adhesive thickness. Good agreements between the present simulations and the experimental results are found.

scholarly journals Finite Element Analysis of Cylindrical and Spherical Concrete Vaults

2020 ◽  
Vol 6 (6) ◽  
pp. 70-75
Author(s):  
Parag Kumar ◽  
Shilpa S
Keyword(s):  
Boundary Condition ◽  
Shear Stress ◽  
Thin Shell ◽  
Maximum Shear Stress ◽  
Shell Structures ◽  
Lightweight Construction ◽  
Spherical Shells ◽  
Element Analysis ◽  
Simply Supported ◽  
Concrete Shell

Concrete shell structures, often cast as a monolithic dome or stressed ribbon bridge or saddle roof. The thin concrete shell structures are a lightweight construction composed of a relatively thin shell made of reinforced concrete, usually without the useof internal supports giving an open unobstructed interior. This project aims to investigate the displacement and to find the maximum shear stress of cylindrical and spherical concrete vaults subjected to pressure load and it’s self-weight. Boundary condition is given for the concrete vaults as simply supported. Concrete vaults of 3m, 6m and 9m span and of length 8m with same loading conditions were applied. If the shear stress is more it is easy to resist the more load on it. ANSYS results shows that the displacement values when compared with cylindrical and spherical shells, Spherical shells can resist more load

scholarly journals Design and analysis of trapezoidal bucket excavator for backhoe

2018 ◽  
Vol 49 ◽  
pp. 02001
Author(s):  
Sumar Hadi ◽  
Bayuseno ◽  
Jamari ◽  
Rachmat Muhamad Andika ◽  
Kurnia Chamid
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Maximum Shear Stress ◽  
Element Analysis ◽  
Maximum Deformation ◽  
Ansys Simulation ◽  
Excavator Bucket ◽  
Stress Result ◽  
Deformation Level

Excavator is the most multifunction heavy tool because it can handle other heavy tool such as sloping, dumptruck loading, and breaker. Usually, when doing excavation there is always possibility of breaking of pin in tooth adapter. The aim of this paper is designing bucket excavator using SOLIDWORK 2016 software and doing analysis with ANSYS R15.0 software using finite element analysis (FEA) method. This paper emphasize about the development that is done in the tip of excavator bucket teeth based on the calculation and ANSYS simulation with maximum shear stress result which is in the amount of 50,437 Mpa with maximum deformation level is being found at the part of excavator bucket head.

Jagged Cracking in the Heat-Affected Zone of Weld Overlay on Coke Drum Cladding

2017 ◽  
Author(s):  
Yiyu Wang ◽  
Rangasayee Kannan ◽  
Leijun Li ◽  
Yasin Suzuk ◽  
Darren Ting ◽  
...  
Keyword(s):  
Shear Stress ◽  
Thermal Stress ◽  
Grain Boundaries ◽  
Heat Affected Zone ◽  
Maximum Shear Stress ◽  
Local Strain ◽  
Inconel 625 ◽  
Intergranular Cracking ◽  
Element Analysis ◽  
M23c6 Carbides

Jagged cracks were observed in SA240 Type 405 stainless steel cladding of Inconel 625 overlay repaired coke drums. It is found that intergranular cracking is the dominant fracture mode in the fine-grained heat-affected zone (FGHAZ) of the boat specimens. The sensitization effect from the operation and welding thermal cycles leads to the depletion of Cr with the preferential precipitation of Cr-rich M23C6 carbides along the grain boundaries. The cladding FGHAZ has the largest frequency of grain boundaries with higher local strain levels and the highest fraction of grain boundary Cr-rich M23C6 carbides. Thermal stress distributions predicted by finite element analysis clearly show the maximum shear stress to exhibit the typical “jagged” pattern near the cracked regions. Thermal expansion coefficient and strength mismatch among the shell base metal, cladding, and overlay is believed to have caused the unique jagged maximum shear stress distribution in the cladding HAZ of Inconel 625 overlay. The magnitude of this thermal stress can reach the yield strength of the cladding at 900 °F (482 °C) service temperature, therefore, provides the driving force for the jagged cracking formation in the sensitized HAZ.

scholarly journals On the Influence of Fracture Criterion on Perforation of High-Strength Steel Plates Subjected to Armour Piercing Projectile

2015 ◽  
Vol 62 (2) ◽  
pp. 157-179 ◽  
Author(s):  
Djalel Eddine Tria ◽  
Radosław Trebinski
Keyword(s):  
Shear Stress ◽  
Fracture Criterion ◽  
Maximum Shear Stress ◽  
Equivalent Plastic Strain ◽  
Stress Triaxiality ◽  
High Strength ◽  
Steel Plates ◽  
Fracture Model ◽  
Simple Material ◽  
Shear Plugging

Abstract This paper presents a numerical investigation of fracture criterion influence on perforation of high-strength 30PM steel plates subjected to 7.62x51 mm Armour Piercing (AP) projectile. An evaluation of four ductile fracture models is performed to identify the most suitable fracture criterion. Included in the paper is the Modified Johnson-Cook (MJC) constitutive model coupled separately with one of these fracture criteria: the MJC fracture model, the Cockcroft-Latham (CL), the maximum shear stress and the constant failure strain models. A 3D explicit Lagrangian algorithm that includes both elements and particles, is used in this study to automatically convert distorted elements into meshless particles during the course of the computation. Numerical simulations are examined by comparing with the experimental results. The MJC fracture model formulated in the space of the stress triaxiality and the equivalent plastic strain to fracture were found capable of predicting the realistic fracture patterns and at the same time the correct projectile residual velocities. However, this study has shown that CL one parameter fracture criterion where only one simple material test is required for calibration is found to give good results as the MJC failure criterion. The maximum shear stress fracture criterion fails to capture the shear plugging failure and material fracture properties cannot be fully characterized with the constant fracture strain

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