scholarly journals Stress Superposition Method and Mechanical Analysis Properties of Regular Polygon Membranes

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 192
Author(s):  
Tao Peng ◽  
Qiuhong Lin ◽  
Bingyan Li ◽  
Ani Luo ◽  
Qiang Cong ◽  
...  
Keyword(s):  
Principal Stress ◽  
Regular Polygon ◽  
Equivalent Stress ◽  
Arbitrary Point ◽  
Effective Area ◽  
Mechanical Analysis ◽  
Superposition Method ◽  
Arch Height ◽  
Calculation Results ◽  
Stress Superposition

In this paper, the stress superposition method (SSM) is proposed to solve the stress distribution of regular polygon membranes. The stress-solving coefficient and the calculation formula of arbitrary point stress of regular polygon membrane are derived. The accuracy of the SSM for calculating stresses in regular polygonal membranes is verified by comparing the calculation results of the SSM with the finite element simulation results. This article is the first to propose a method to investigate the response of the arch height of the membrane curved edge to the membrane’s mechanical properties while keeping the effective area constant. It is found that the equivalent stress and the second principal stress at the midpoint of the membrane curved edge are effectively increased with the increase of the arch height of the curved edge. The second principal stress at the edge region of the membrane is relatively small, leading to the occurrence of wrinkles. When the stress at the midpoint of the curved edge is equal to that at the center of the membrane, the membrane plane attains the maximum stiffness and reduces the possibility of wrinkling at the edge.

Thermo-mechanical analysis and optimization of functionally graded rotating disks

2020 ◽  
Vol 55 (5-6) ◽  
pp. 159-171
Author(s):  
Hassan Mohamed Abdelalim Abdalla ◽  
Daniele Casagrande ◽  
Luciano Moro
Keyword(s):  
Finite Element ◽  
Equivalent Stress ◽  
Rotating Disk ◽  
Mechanical Analysis ◽  
Theory Of Elasticity ◽  
Functionally Graded ◽  
Rotating Disks ◽  
Maximum Equivalent Stress ◽  
Quadratic Programming Method ◽  
Stress Uniformity

The behavior of thermo-mechanical stresses in functionally graded axisymmetric rotating hollow disks with variable thickness is analyzed. The material is assumed to be functionally graded in the radial direction. First, a two-dimensional axisymmetric model of the functionally graded rotating disk is developed using the finite element method. Exact solutions for stresses are then obtained assuming that the plane theory of elasticity holds. These solutions are in accordance with finite element ones, thus showing the validity of the assumption. Finally, in order to reduce the maximum equivalent stress along the radius, the optimization of the material distribution is addressed. To avoid subsequent finite element simulations in the optimization process, which can be computationally demanding, a nonlinear constrained optimization problem is proposed, for which the solution is obtained numerically by the sequential quadratic programming method, showing prominent results in terms of equivalent stress uniformity.

The Analysis of Security Wedge Lock-Rope Mechanism by ANSYS Finite Element Analysis

2015 ◽  
Vol 713-715 ◽  
pp. 107-113 ◽  
Author(s):  
Kou Bao Fu ◽  
Fan Peng
Keyword(s):  
Finite Element Analysis ◽  
Equivalent Stress ◽  
Wedge Angle ◽  
Mechanical Analysis ◽  
Wire Rope ◽  
Element Analysis ◽  
Efficient Operation ◽  
Relative Slip ◽  
Local Equivalent ◽  
Hoisting System

The performance of lock-rope mechanism affects the safe and efficient operation of mine hoisting system directly. The lock-rope mechanism with wedge angle 5° was designed by the mechanical analysis of wedge lock rope. Its entity model was established and the dynamic process of working is simulated by using the ANSYS/LS-DYNA. The results show that the wedge lock rope mechanism has the ability of self-locking. The strengthening institutions can largely eliminate the relative slip momentum between the lock-rope wedge-block and wire rope, which make the movement trend gentle, reduce the wear between the lock-rope wedge-block and wire rope and improve the security of wedge lock-rope mechanism effectively. The local equivalent stress of lock-rope wedge-block and wire rope are both present in the increasing distribution gradually from the upper to the lower.

Mechanical Analysis for Anchorage Zone Connecting Main Cable and Main Girger of Self-Anchored Suspension Bridge

2012 ◽  
Vol 178-181 ◽  
pp. 2281-2284 ◽  
Author(s):  
Qing Tian Su ◽  
Dong Fang Wang
Keyword(s):  
Mechanical Behavior ◽  
Suspension Bridge ◽  
Mechanical Analysis ◽  
Calculation Model ◽  
Refined Model ◽  
Main Cable ◽  
Spatial Beam ◽  
Critical Issues ◽  
Calculation Results ◽  
Main Girder

Self-anchored suspension bridge is a self-balancing system by anchored the main cable at each end of main girder. With complicated configuration and important rule of transferring tension in main cable to main girder, the anchorage region is one of the most critical issues during designing a self-anchored suspension bridge. It is impossible to fully understand the mechanical behavior only by spatial beam and column model but spatial refined model. Because the behavior of anchorage region is greatly influenced by its boundary condition, in this paper, reasonable length of main girder in calculation model is discussed based on the spatial refined model. The mechanical behavior of initial anchorage structure is calculated. A modified anchorage configuration is proposed according to the stresses distribution of anchorage zone. Calculation results show the modified anchorage configuration can make the force transferring smoothly and decrease the stresses of anchorage structure, and it can be referenced to similar bridges.

Thermal Stresses of Through Silicon Vias and Si Chips in Three Dimensional System in Package

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Takahiro Kinoshita ◽  
Takashi Kawakami ◽  
Tatsuhiro Hori ◽  
Keiji Matsumoto ◽  
Sayuri Kohara ◽  
...  
Keyword(s):  
Yield Stress ◽  
Principal Stress ◽  
Thermal Conduction ◽  
Thermal Stresses ◽  
Bending Strength ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Maximum Principal Stress ◽  
Dimensional System ◽  
Three Dimensional System

Thermal conduction and mechanical stresses in through silicon via (TSV) structures in three dimensional system in package (3D SiP) under device operation condition were discussed. A large scale simulator, ADVENTURECluster® based on finite element method (FEM) was used to simulate the effects of voids formed inside Cu TSVs on the thermal conduction and mechanical stresses in the TSV structure. The thermal performance that was required in 3D SiP was estimated to ensure the reliability. Simulations for thermal stresses in the TSV structure in 3D SiP were carried out under thermal condition due to power ON/OFF of device. In case that void was not present inside the TSV, the stresses in TSV were close to the hydrostatic pressure and the magnitude of the equivalent stress was lower than the yield stress of copper. Maximum principal stress of the Si chip in the TSV structure for the case without voids was lower than that of the bending strength of silicon. However, the level of the stresses in the Si chips should not be negligible for damages to Si chips. In case that void was present inside the TSV, stress concentration was occurred around the void in the TSV. The magnitude of the equivalent stress in the TSV was lower than the yield stress of copper. The magnitude of the maximum principal stress of the Si chip was lower than that of the bending strength of silicon. However, its level should not be negligible for damages to TSVs and Si chips. The stress on inner surfaces of Si chip was slightly reduced due to the presence of a void in the TSV.

Simulation on Pellet-Cladding Mechanical Interaction (PCMI) of Accident Tolerant Fuel (ATF) With Coated Cladding

2017 ◽  
Author(s):  
Yangbin Deng ◽  
Bowen Qiu ◽  
Yingwei Wu ◽  
Dalin Zhang ◽  
Wenxi Tian ◽  
...  
Keyword(s):  
Surface Coating ◽  
External Surface ◽  
Equivalent Stress ◽  
Internal Surface ◽  
Mechanical Analysis ◽  
Calculation Model ◽  
Mechanical Interaction ◽  
Fuel Pellets ◽  
Thermal Mechanical Analysis ◽  
Control Volumes

In this study, based on the code FROBA (Fuel ROd Behavior Analysis), a thermal-mechanical analysis code initially developed for traditional UO2-Zr fuel elements by our research group, a modified version named FROBA-ATF was developed to perform the fuel performance simulation of ATFs with different claddings, including Zr-4, SiC and Zr-4 coated with SiC. Compared with initial version, the cladding could be divided into arbitrary number control volumes with different materials in the new code, so it can be used to perform the calculation for multilayer coatings. In addition, a new non-rigid PCMI calculation model was established in the new code. Neither of the cladding and the pellet was regarded as the rigid body in this study, which means it can provide more accurate prediction compared with the rigid-fuel model in the initial code when Pellet-cladding Mechanical Interaction (PCMI) happened. The FROBA-ATF code was used to predict PCMI performance of two kind fuels with coated claddings, including the internal-surface coating and external-surface coating. The calculation result indicates that because the coating surface was close to the inner surface of the clad where also was the PCMI surface, the absolute value of the combine pressure of internal-surface coated cladding was substantial larger than that of the external-surface coated cladding, which might be harmful the coating behavior. However, the internal-surface coated mode can provide a protection for alloy due to the isolation from direct contact with fuel pellets, which can result in a much lower equivalent stress of zirconium body during the PCMI.

Thermal-Mechanical Analysis for Surface Cracks on FTSC Slab

2010 ◽  
Vol 152-153 ◽  
pp. 843-846
Author(s):  
Li Guang Zhu ◽  
Jian Chen ◽  
Ying Xu ◽  
Jing Jing Guo
Keyword(s):  
Plastic Property ◽  
Mechanical Analysis ◽  
Phase Region ◽  
Surface Cracks ◽  
Uniform Temperature ◽  
Shell Surface ◽  
Two Phase ◽  
Columnar Crystal ◽  
Calculation Results ◽  
Thermal Mechanical Analysis

Calculation of steel solidification in H2 mould of FTSC with Two-dimensional thermal- mechanical coupled method, results show that steel in mould has a wide two-phase region which grows rapidly during solidification, so columnar crystal and coarse grain were well-developed. Stress calculation results show that internal tensile stress reach to 13-17MPa in two-phase region, and the closer to shell surface, the greater of SEQV. It has the condition for microcracks generation and growth in Mould. Control heat transfer in mould can uniform temperature distribution, thereby reduce stress and enhance the plastic property of shell.

A High Precision and Convenient Method to Analyze the Mechanics of Scissor Lift Platform under the Action of Combined Loads

2014 ◽  
Vol 618 ◽  
pp. 503-508
Author(s):  
Fei Peng Qu ◽  
Yuan Xue
Keyword(s):  
Calculation Method ◽  
Virtual Work ◽  
Optimization Method ◽  
Mechanical Analysis ◽  
Drive Unit ◽  
Typical Structure ◽  
Virtual Work Principle ◽  
Nodal Force ◽  
Combined Loads ◽  
Calculation Results

Scissor lift platform had lots of kinematic pairs and the mechanics relations between them were complex. So mechanics analysis became the focus by researchers. The mechanical model of scissor lift platform under the action of combined loads was built in the paper. The calculation formula of nodal force of scissor transmission unit was given used the transfer matrix method. The calculation formulas of drive units were given on the virtual work principle. Also the calculation method of nodal forces of drive units was given. How the different distributions of drive unit influence on the nodal force was analyzed. The drive units’s position optimization method was given in this paper. In order to verify the reliability of this calculation method, an calculation example of typical structure was given. The calculation results given by the method in this paper was identical with the result given by finite element method. The conclusions obtained could serve as theoretical guidance and reference for mechanical analysis and optimal design of scissor transmission mechanism.

scholarly journals Analysis of plastic zones in surrounding rocks around a circular tunnel considering the effect of intermediate principal stress and heterogeneity

2019 ◽  
Vol 275 ◽  
pp. 03007 ◽  
Author(s):  
Shuxin Deng ◽  
Yonglai Zheng ◽  
Lipo Feng ◽  
Le Van Tuan ◽  
Cuizhou Yue ◽  
...  
Keyword(s):  
Plastic Zone ◽  
Principal Stress ◽  
Lateral Pressure ◽  
Pressure Coefficient ◽  
Plastic Zone Size ◽  
Intermediate Principal Stress ◽  
Circular Tunnel ◽  
Lateral Pressure Coefficient ◽  
Calculation Results ◽  
Coulomb Criterion

Based on a modified Mohr-Coulomb criterion with a non-uniform coefficient, a calculation method of plastic zone boundary of surrounding rocks in a circular tunnel in non-uniform stress field is established. Both the effects of intermediate principal stress and heterogeneity are studied. With the increase of the intermediate principal stress, the plastic zone size of the surrounding rocks will decrease first and then increase. Lateral pressure coefficient has an effect on the shape of the plastic zone. With the increase of lateral pressure coefficient, the plastic zone gradually becomes uniform, and the failure of surrounding rock develops upward and downward from both sides. As non-uniform coefficient increases, the material is more uniform and the effect of intermediate principal stress on the plastic zone is less significant. If the effect of intermediate principal stress is not taken into account, the calculation results tend to be consistent with results calculated by the Mohr-Coulomb criterion, which are considered to be conservative.

Stress Superposition Method and free vibration of corner tensioned rectangular thin membranes

2020 ◽  
pp. 107201
Author(s):  
Bingyan Li ◽  
Rongqiang Liu ◽  
Qiang Cong ◽  
Hongwei Guo ◽  
Qiuhong Lin
Keyword(s):  
Free Vibration ◽  
Superposition Method ◽  
Thin Membranes ◽  
Stress Superposition

scholarly journals The Stress and Reliability Analysis of HTR’s Graphite Component

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Xiang Fang ◽  
Haitao Wang ◽  
Suyuan Yu
Keyword(s):  
High Temperature ◽  
Reliability Analysis ◽  
Reactor Core ◽  
Mechanical Analysis ◽  
Normal Operation ◽  
Reliability Models ◽  
Analysis Process ◽  
Close Relationship ◽  
Calculation Results ◽  
Stress Accumulation

The high temperature gas cooled reactor (HTR) is developing rapidly toward a modular, compact, and integral direction. As the main structure material, graphite plays a very important role in HTR engineering, and the reliability of graphite component has a close relationship with the integrity of reactor core. The graphite components are subjected to high temperature and fast neutron irradiation simultaneously during normal operation of the reactor. With the stress accumulation induced by high temperature and irradiation, the failure risk of graphite components increases constantly. Therefore it is necessary to study and simulate the mechanical behavior of graphite component under in-core working conditions and forecast the internal stress accumulation history and the variation of reliability. The work of this paper focuses on the mechanical analysis of pebble-bed type HTR's graphite brick. The analysis process is comprised of two procedures, stress analysis and reliability analysis. Three different creep models and two different reliability models are reviewed and taken into account in simulation. The stress and failure probability calculation results are obtained and discussed. The results gained with various models are highly consistent, and the discrepancies are acceptable.

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