Assessment of Error and Pressure Influence on Total Equivalent Stress Amplitude Calculation by WRC107

2011 ◽  
Author(s):  
Fujun Liu ◽  
Yueqiang Qian ◽  
Zhangwei Ling ◽  
Shuai Kong ◽  
Mulin Zheng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Shell Theory ◽  
Stress Amplitude ◽  
Equivalent Stress ◽  
External Loading ◽  
Calculation Error ◽  
Fatigue Evaluation ◽  
Chinese Standard ◽  
Equivalent Stress Amplitude

Bulletin WRC107 is most commonly used in attachment design, but still some uncertainties make it difficult to ensure safety in recent use. Two problems in fatigue evaluation were addressed here, first the bulletin is based on shell theory and some other assumption, and for various condition the calculation error is unknown; second pressure is not considered in calculation. To the first problem, an assessment was performed by comparing the total equivalent stress results of WRC107 and of finite element method (FEM). To the second problem, a method from Chinese standard HG20582-1998 Specification for Stress Calculation of Steel Chemical Vessels (HG method) was introduced as a supplement, and the reliability was studied. The results show that, total equivalent stress amplitude calculated by WRC107 may be underestimated, and its error mainly depends on parameters β and γ. Complemented by HG method, WRC107 could be used in calculation of shell under pressure and external loading.

Thermal Fatigue Evaluation Method of Pipes by Equivalent Stress Amplitude

2012 ◽  
Author(s):  
Takafumi Suzuki ◽  
Naoto Kasahara
Keyword(s):  
Fatigue Damage ◽  
Thermal Fatigue ◽  
Evaluation Method ◽  
Stress Amplitude ◽  
Equivalent Stress ◽  
Safety Margin ◽  
Evaluation Procedure ◽  
Fatigue Evaluation ◽  
High Cycle Thermal Fatigue ◽  
Equivalent Stress Amplitude

In recent years, reports have increased which are about failure cases caused by high cycle thermal fatigue both at light water reactors and fast breeder reactors. One of the biggest reasons of the cases is a turbulent mixing at a Tee-junction, where hot and cold temperature fluids are mixed, in a coolant system. In order to prevent thermal fatigue failures at Tee-junctions, The Japan Society of Mechanical Engineers (JSME) published the guideline S017-2003 (or JSME guideline) which is an evaluation method of high cycle thermal fatigue damage at a nuclear piping. It has some limitations in terms of its inconstant safety margin and its complexity in evaluation procedure, however. In order to solve these limitations, this paper proposes a new evaluation method of thermal fatigue damage with use of the “equivalent stress amplitude” which represents random temperature fluctuation effects on thermal fatigue damage. Because this new method makes methodology of evaluation clear and concise, it will contribute to improving the guideline for thermal fatigue evaluation.

Finite Element Analysis on the Fatigue Stresses of a Railway Vehicle Roller Bearing

2008 ◽  
Vol 44-46 ◽  
pp. 935-941 ◽  
Author(s):  
Feng Lin ◽  
Yong Xiang Zhao
Keyword(s):  
Finite Element ◽  
Stress Amplitude ◽  
Equivalent Stress ◽  
Roller Bearing ◽  
Fe Analysis ◽  
Local Analysis ◽  
Interactive System ◽  
Railway Vehicle ◽  
Load Spectrum ◽  
Equivalent Stress Amplitude

The distributed fatigue stresses of 353130B roller bearing of China freight car with K5 type titling bogie are investigated using an elastic-plastic finite element (FE) analysis. Policy of two steps is applied. First, an integral FE analysis is performed on adapter-bearing-axle-wheel-track interactive system. Second, local analysis is applied to the local axle-bearing-adapter part, in which on the section of axle is with the bound condition obtained from the integral analysis. Wheel contact force spectrum on a curved railway line by on-line inspection is used for the present study. Previous proposed multivariate quadratic regression approach is applied for transferring the load spectrum to the dynamic stress spectrum at a special position of the bearing. Results reveal that the rollers, innerand outer-rings of bearing are subjected to distribute axially equivalent stress amplitude. The closer to axle side, the larger the equivalent stress amplitude. The equivalent stress amplitude of outer ring at the position close to the seal seat is relative larger to that of inner ring. The results are consistency with the shell failures of the bearings in production. Availability of present study is indicated.

Composite Solutions for Deck Catamarans

2018 ◽  
Vol 55 (1) ◽  
pp. 1-4
Author(s):  
Elena Felicia Beznea ◽  
Ionel Chirica ◽  
Adrian Presura ◽  
Ionel Iacob
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Sandwich Structure ◽  
High Strength ◽  
Total Weight ◽  
External Loading ◽  
Strength Analysis ◽  
Allowable Stress ◽  
The Finite Element Method ◽  
Inland Navigation

The paper is treating the strength analysis of the main deck structure of an inland navigation catamaran for 30 passengers. The main deck should have high stiffness and high strength to resist to external loading and endure high stresses from combined bending and torsion loads. Different materials for sandwich structure of the deck have been analysed by using the Finite Element Method in order to determine the solution which accomplish better designing criteria regarding allowable stress and deformations and total weight.

Investigation of Strength in G4-73 Type Centrifugal Fan Impeller

2011 ◽  
Vol 383-390 ◽  
pp. 5669-5673
Author(s):  
Song Ling Wang ◽  
Zhe Sun ◽  
Zheng Ren Wu
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Calculation Result ◽  
Working Condition ◽  
Equivalent Stress ◽  
Centrifugal Fan ◽  
The Finite Element Method ◽  
Total Displacement ◽  
Maximum Equivalent Stress

For the large centrifugal fan impeller, its working condition generally is bad, and its geometry generally is complex. So its displacements and stresses distribution are also complex. In this paper, we can obtain the fan impeller’s displacements and stresses distribution accurately through numerical simulation in G4-73 type centrifugal fan impeller using the finite element method software ANSYS. The calculation result shows that the maximum total displacement of the impeller is m, it occurs on the position of the half of the blade near the outlet of the impeller; and the maximum equivalent stress of the impeller is 193 MPa, it occurs on the contacted position of the blade and the shroud near inlet of the impeller. Furthermore, check the impeller strength, the result shows that the strength of the impeller can meet the requirement.

Influence of Attachment Rigidity on Stress Analysis

2011 ◽  
Vol 138-139 ◽  
pp. 74-78
Author(s):  
Yue Qiang Qian ◽  
Fu Jun Liu ◽  
Zhang Wei Ling ◽  
Shuai Kong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Cylindrical Shell ◽  
Stress Analysis ◽  
Shell Thickness ◽  
Equivalent Stress ◽  
Local Stress ◽  
Pressure Vessels ◽  
Equivalent Stresses ◽  
Typical Method

In pressure vessels design, WRC107 provides a typical method of local stress analysis to supports and attachments. But influence of the rigidity of attachments on calculation is not considered. For fatigue analysis of round hollow attachment on cylindrical shell, equivalent stresses calculated by WRC107 were compared with those by finite element method. Three attachment thickness configurations, that half, equal, double of the shell thickness were tested. Results show that, in key point Au defined by WRC107 equivalent stress decreases while attachment rigidity increases, and in key point Cu, equivalent stress increases while attachment rigidity increases. When the thickness of attachment equals to that of shell, equivalent stress of WRC107 in Cu comes closest to FEM.

Transient Dynamics Analysis of Hammer Rod Impact Based on ANSYS

2012 ◽  
Vol 619 ◽  
pp. 135-138
Author(s):  
Jing Jing Wang ◽  
Xu Hong Cui ◽  
Wen Xin Xu ◽  
Miao Xie ◽  
Jun Meng
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Simulation Analysis ◽  
Equivalent Stress ◽  
Structure Design ◽  
Dynamics Simulation ◽  
Transient Dynamics ◽  
Dynamics Analysis ◽  
Air Hammer ◽  
Stress Contour

Regarding the liquid-air hammer rod as the research object, the equivalent stress contour of the hammer rod has been obtained through transient dynamics simulation analysis of the hammer rod impact process by using finite element method. This paper has studied node rate response in different positions of the hammer rod to provide evidence for structure design of this kind of impact members.

Effect of Load-Relieving Structure against Overload under High Overload

2013 ◽  
Vol 328 ◽  
pp. 421-425
Author(s):  
Quan Li Ning ◽  
Jun Li ◽  
Dong Chen ◽  
Gao Peng Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Constitutive Equation ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Load Condition ◽  
High Load ◽  
Dynamical Response ◽  
Response Distribution ◽  
High Load Condition

Three-dimensional visco-elastic lame deformation incremental constitutive equation is derived based on Total Lagrangian method, and structural dynamical response distribution in the grain during launching is simulated numerically by finite element method under high load condition for projectile-based equipment, the equivalent stress in the bottom of load-relieving structure and the Y-displacement in the top of load-relieving structure are calculated. The results show that the stress is ameliorated after the function of load-relieving subassembly, and it can decrease impact. Also Y-displacement is accord with limit request, and when reaching the maximum, the transmutation will be comeback.

Equivalent Stress Analysis of Piercing Process in Diescher’s Mill Using Finite Element Method

2013 ◽  
Vol 648 ◽  
pp. 170-173
Author(s):  
Lu Lu ◽  
Zhao Xu Wang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Structural Evolution ◽  
Work Piece ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Distribution Of Stress ◽  
Element Method

In this paper, the simulation of the piercing process is performed by the three dimensional finite element method in Diescher’s mill. After a short description of the problem the numerical model of the process is described. The simulated results visualize dynamic evolution of equivalent stress, especially inside the work-piece. The non-uniform distribution of stress on the internal and external surface of the work-piece is a distinct characteristic of processing tube piercing. And it is the basic data for improving tool and design, predicting, damage and controlling the micro-structural evolution of processing tube piercing.

Design Optimization for Double-T Root and Rim of Turbine Blade with Three-Dimensional Finite Element Method

2012 ◽  
Vol 215-216 ◽  
pp. 239-243
Author(s):  
Ming Hui Zhang ◽  
Di Zhang ◽  
Yong Hui Xie
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Optimization ◽  
Turbine Blade ◽  
Equivalent Stress ◽  
Three Dimensional ◽  
Maximum Equivalent Stress ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Element Method

As the main bearing part in a turbine blade, the root carries most of the loads of the whole blade. The improvement of the root structure can be used to enhance the operation reliability of steam turbine. The research on design optimization for double-T root and rim of a turbine blade was conducted by three-dimensional finite element method. Based on the APDL (ANSYS parametric design language), a multi-variable parametric model of the double-T root and rim was established. Twelve characteristic geometrical variables of the root-rim were optimized to minimize the maximum equivalent stress. The optimal structure of the double-T root-rim is obtained through the optimization. Compared with the original structure, the equivalent stress level of the root and rim has a significant reduction. Specifically, the maximum equivalent stress of root and rim reduces by 14.25% and 13.59%, respectively.

Finite Element Analysis of Hydraulic Clipping Machine Shear Platform Dased on ANSYS

2014 ◽  
Vol 945-949 ◽  
pp. 190-193
Author(s):  
Hai Lin Wang ◽  
Yi Hua Sun ◽  
Ming Bo Li ◽  
Gao Lin ◽  
Yun Qi Feng ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Elastic Strain ◽  
Optimization Design ◽  
Equivalent Stress ◽  
Element Model ◽  
Element Analysis ◽  
Maximum Equivalent Stress

Q43Y-85D type crocodile hydraulic clipping machine was taken as research object to optimization design. A finite element model for clipping machine was built using shell unit as fundamental unit. ANSYS12.0 finite element method was used to analyze the deformation and stress distribution of the shear platform model of hydraulic clipping machine. The result showed that the maximum equivalent stress at the dangerous area was 368.162 MPa and the maximum elastic strain was 0.1814×10-2 mm. After the structural optimization design, it was found that the maximum equivalent stress decreased to 186.238 MPa which did not exceed the material’s yield limitation 215 MPa and the maximum elastic strain decreased to 0.919×10-3 mm which satisfied the requirement of stiffness.

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