Analytical Solution of Stress and Displacement Fields of Frozen Wall in Deep Alluvium According for Time-Space Effect

2012 ◽  
Vol 170-173 ◽  
pp. 1820-1826
Author(s):  
Mao Yan Ma ◽  
Hua Cheng ◽  
Chuan Xin Rong
Keyword(s):  
Analytical Solution ◽  
Radial Stress ◽  
Displacement Fields ◽  
Time Space ◽  
Stress And Displacement Fields ◽  
Calculation Results ◽  
Space Effect ◽  
Frozen Wall ◽  
Theory Of Viscoelasticity ◽  
Shaft Wall

Based on the theory of viscoelasticity and the principle of interaction between surrounding rock and structure in unload state, analytical solution of the stress field and displacement field of the frozen wall is obtained. Calculation results of the stress and displacement fields suggest that radial stress and displacement in the sidewall are very large within 15 days after pouring concrete of the outer shaft wall, which is proved by the fact that engineering incidents such as shaft wall rupture happen exactly at this time. The results also indicate that radial stress at different points in frozen wall all tend to the imposed loads on outer frozen wall finally, and that means the frozen wall is fluidized. This calculation theory can be used in the design of frozen wall in deep alluvium.

scholarly journals APPLICATION OF QUARTER-POINT SINGULAR ELEMENT IN FINITE ELEMENT METHOD TO SIMULATION OF CRACK TIP BEHAVIOR

2010 ◽  
Vol 13 (2) ◽  
pp. 5-13
Author(s):  
Thien Tich Truong ◽  
Bang Kim Tran
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Fracture Mechanics ◽  
Crack Tip ◽  
Singular Element ◽  
Displacement Fields ◽  
Mathematical Background ◽  
Stress And Displacement Fields ◽  
Calculation Results ◽  
Element Method

Fracture mechanics is a new branch in engineering. The development of modern mathematical background with different numerical methods has supported fracture mechanics to solve many complex fracture problems in practice effectively. This article introduces the application of quarter - point singular element in finite element method to simulate crack tip behavior in two dimensional problems. The ANSYS and FRANC2D programs are used to compute stress intensity factor, simulate the stress and displacement fields near crack tip and simulate crack propagation. The calculation results are compared with analytical results and the results in other articles.

scholarly journals Exact Solution for Functionally Graded Variable-Thickness Rotating Disc with Heat Source

2010 ◽  
Vol 224 (11) ◽  
pp. 2316-2331 ◽  
Author(s):  
M Bayat ◽  
A H Mohazzab ◽  
B B Sahari ◽  
M Saleem
Keyword(s):  
Heat Source ◽  
Variable Thickness ◽  
Thermal Load ◽  
Radial Stress ◽  
Mechanical Load ◽  
Functionally Graded ◽  
Displacement Fields ◽  
Rotating Disc ◽  
Thickness Profile ◽  
Stress And Displacement Fields

Exact elastic solutions for axisymmetric variable-thickness hollow rotating discs with heat source made of functionally graded (FG) materials under free—free and fixed—free boundary conditions are presented. Material properties and disc thickness profiles are assumed to be represented by specified power law distributions. The effect of the heat source and the geometry of the disc on stress and displacement fields are investigated. It is found that the location of maximum radial stress owing to thermal load does not tend towards the outer surface like radial stress owing to mechanical load for free—free FG discs with an increase in parameter m related to the thickness profile. The temperature distribution in a disc with hyperbolic thickness profile is the smallest compared with other thickness profiles. The FG disc with hyperbolic convergent thickness profile has smaller stresses because of thermal load compared with the disc with uniform thickness profile.

A Stress Singularity Parameter Approach for Evaluating the Interfacial Reliability of Plastic Encapsulated LSI Devices

1989 ◽  
Vol 111 (4) ◽  
pp. 243-248 ◽  
Author(s):  
T. Hattori ◽  
S. Sakata ◽  
G. Murakami
Keyword(s):  
Adhesive Strength ◽  
Evaluation Method ◽  
Stress Singularity ◽  
The Finite Element Method ◽  
Displacement Fields ◽  
Stress And Displacement Fields ◽  
Ni Alloy ◽  
Base Resin ◽  
Interfacial Reliability ◽  
Parameter Approach

Since the stress and displacement fields near a bonding edge show singularity behaviors, the adhesive strength evaluation method, using maximum stresses calculated by a numerical stress analysis such as the finite element method, is generally not valid. In this paper, a new method, which uses two stress singularity parameters, is presented for evaluating adhesive strength. This method is applied to several kinds of molded models, composed of epoxy base resin and Fe-Ni alloy sheets, and plastic encapsulated LSI models. Predictions about the initiation and extension of delamination are compared with the results of observations made by scanning acoustic tomography on these models.

Research on Deformation Mechanism of Surrounding Rock during Excavation of Large-Span Shallow-Buried Double-Arch Tunnel

2013 ◽  
Vol 392 ◽  
pp. 890-894
Author(s):  
Shao Rui Sun ◽  
Ye Xu Lu ◽  
Shao Hua Zhang ◽  
Ji Min Wu
Keyword(s):  
Deformation Mechanism ◽  
Back Analysis ◽  
Ground Surface ◽  
Surrounding Rock ◽  
Tunnel Excavation ◽  
Large Span ◽  
Main Work ◽  
Time Space ◽  
Space Effect ◽  
Force Mechanism

The deformation mechanism of surrounding rock during excavation is difficult to stability evaluation for large-span shallow-buried double-arch tunnel. Take Fenghuang mountain tunnel in Suzhou city as an example, the main work and funding are as follow: The measured data in the middle of the tunnel, including settlement on the top of the tunnel and deformation between two lateral walls, were used to calculate mechanical parameters by back analysis method. The obtained parameters were used to calculate the deformation and stress of the main tunnel excavation in the different steps. The rules includes time-space effect during main tunnel excavation, force mechanism of the middle wall and settlement on the ground surface for the surrounding rock in the main tunnel. Finally, the calculated settlement and deformation were compared to the monitoring results. The safety coefficient of surrounding rock for double-arch tunnel was obtained by strength reduction theory.

Propagation and Opening of a Through Crack in a Pipe Subject to Combined Cyclic Thermomechanical Loading

1976 ◽  
Vol 98 (1) ◽  
pp. 17-25 ◽  
Author(s):  
T. R. Hsu ◽  
A. W. M. Bertels
Keyword(s):  
Bauschinger Effect ◽  
Thermal Loading ◽  
Thin Wall ◽  
Pipe Material ◽  
Displacement Fields ◽  
Stress And Displacement Fields ◽  
Growing Crack ◽  
Cyclic Plastic Deformation ◽  
Cyclic Thermomechanical Loading ◽  
Thermoelastic Plastic

The present investigation deals with the propagation and opening of a single crack in a thin wall pipe subject to cyclic pressure and thermal loading. A thermoelastic-plastic analysis based on the finite element variational technique is used to calculate the stress and displacement fields in the vicinity of the growing crack. A special type of element known as a “breakable element” is developed to model the gradual propagation of the crack. Kinematic work hardening is included to account for the Bauschinger effect of the pipe material when subjected to cyclic plastic deformation.

Convergence Study on Application of the Over-Deterministic Method for Determination of Near-Tip Fields in a Cracked Plate Loaded in Mixed-Mode

2012 ◽  
Vol 249-250 ◽  
pp. 76-81 ◽  
Author(s):  
Lucie Šestáková ◽  
Václav Veselý
Keyword(s):  
Mixed Mode ◽  
Brittle Materials ◽  
Higher Order ◽  
Displacement Fields ◽  
Deterministic Method ◽  
Crack Behavior ◽  
Stress And Displacement Fields ◽  
Higher Order Terms ◽  
Convergence Study

Multi-parameter description of crack behavior in quasi-brittle materials offers still enough space for investigations. Several studies have been carried out by the authors in this field [1-3]. One part of the publications by the authors (this work included) contain analyses of the accuracy, convergence and/or tuning of the over-deterministic method that enables determination of the coefficients of the higher-order terms in Williams expansion approximating the stress and displacement fields in a cracked body without any complicated FE formulations. These intermediate studies should bring together a list of recommendations how to use the ODM as effectively as possible and obtain reliable enough values of coefficients of the higher-order terms. Thus, the stress/displacement field can be determined precisely even in a larger distance from the crack tip, which is crucial for assessment of the fracture occurring in quasi-brittle materials.

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