Stability Analysis of Stiffened Plates Based on State-Vector Equation

2013 ◽  
Vol 671-674 ◽  
pp. 1561-1569
Author(s):  
Yan Li Wang ◽  
Guang Hui Qing
Keyword(s):  
Finite Element ◽  
State Vector ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Stiffened Plates ◽  
Variation Principle ◽  
Element Formulation ◽  
Vector Equation ◽  
Finite Element Software ◽  
The Stability

Firstly, based on the theory of state-vector equation, the semi-analysis finite element formulation for the stability of the plates under various boundary conditions was derived by modified Hellinger-Reissner (H-R) variation principle for the elastic material. Secondly, the three-dimensional models for the stability of stiffened plates were established. The semi-analytical solution of state equation for the stability of stiffened plates are proved to be efficient and accurate by comparing with the exact solutions of references and the numerical solutions of the finite element software through several examples.

Numerical solutions for strain-softening surrounding rock under three-dimensional principal stress condition

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Sheng Yu-ming ◽  
Li Chao ◽  
Xia Ming-yao ◽  
Zou Jin-feng
Keyword(s):  
Finite Element ◽  
Principal Stress ◽  
Stress Condition ◽  
Strain Softening ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Strength Criterion ◽  
Surrounding Rock ◽  
Flow Rule ◽  
Finite Element Software

Abstract In this study, elastoplastic model for the surrounding rock of axisymmetric circular tunnel is investigated under three-dimensional (3D) principal stress states. Novel numerical solutions for strain-softening surrounding rock were first proposed based on the modified 3D Hoek–Brown criterion and the associated flow rule. Under a 3D axisymmetric coordinate system, the distributions for stresses and displacement can be effectively determined on the basis of the redeveloped stress increment approach. The modified 3D Hoek–Brown strength criterion is also embedded into finite element software to characterize the yielding state of surrounding rock based on the modified yield surface and stress renewal algorithm. The Euler implicit constitutive integral algorithm and the consistent tangent stiffness matrix are reconstructed in terms of the 3D Hoek–Brown strength criterion. Therefore, the numerical solutions and finite element method (FEM) models for the deep buried tunnel under 3D principal stress condition are presented, so that the stability analysis of surrounding rock can be conducted in a direct and convenient way. The reliability of the proposed solutions was verified by comparison of the principal stresses obtained by the developed numerical approach and FEM model. From a practical point of view, the proposed approach can also be applied for the determination of ground response curve of the tunnel, which shows a satisfying accuracy compared with the measuring data.

Structural Design and Analysis of Aluminum Dome for Caofeidian Coal Storage

2016 ◽  
Vol 710 ◽  
pp. 396-401 ◽  
Author(s):  
Ze Chao Zhang ◽  
Hong Bo Liu ◽  
Xiao Dun Wang ◽  
Xiang Yu Yan ◽  
Jing Hai Yu ◽  
...  
Keyword(s):  
Finite Element ◽  
Aluminum Alloys ◽  
Three Dimensional ◽  
Single Layer ◽  
Element Model ◽  
Internal Force ◽  
Structural Deformation ◽  
Mode Analysis ◽  
Finite Element Software ◽  
The Stability

The upper part of Caofeidian coal storage was approximately hemispherical aluminum shell, covered with aluminum alloys plate. The capsule was made of aluminum alloys material, and its span was 125 meters. In the design, according to TEMCOR joint, we used the finite element software MIDAS to build the accurate geometry models and calculation models of aluminum alloys single layer latticed dome structures. By the combination of constant loads, live loads, snow load, wind load, temperature effect and other working conditions, we summarized the consumption of aluminum of the structures, and studied the structural internal force, structural deformation and structural stiffness. In addition, the X and Y two different direction seismic dynamic load was applied to the structure. The structural seismic performance under two kinds of modes were studied through the structure mode analysis of the vibration frequency. The vierendeel dome and single layer dome were controlled by the stability. ANSYS three-dimensional frame element model were set up, and the eigenvalue buckling analysis was carried out. By the geometrical nonlinear finite element method, combining with initial imperfections and material nonlinear, we found out the stability coefficient and the weak parts of the structure.

Fracture Analysis of Cracks in Anisotropic Materials Using 3DFAS and ANSYS®

2006 ◽  
Author(s):  
U. Ozkan ◽  
A. C. Kaya ◽  
A. Loghin ◽  
A. O. Ayhan ◽  
H. F. Nied
Keyword(s):  
Finite Element ◽  
Numerical Solutions ◽  
Parametric Design ◽  
Three Dimensional ◽  
Crack Tip ◽  
Fracture Analysis ◽  
Anisotropic Materials ◽  
Finite Element Software ◽  
Crack Problems ◽  
Analysis System

The analysis of two and three dimensional fracture mechanics problems in anisotropic materials using ANSYS finite element software and 3DFAS (Three Dimensional Fracture Analysis System) is examined in this study. The methodology uses analytically derived generalized plane strain crack tip fields in anisotropic materials and is implemented into an ANSYS Macro using ANSYS Parametric Design Language. It is shown that quarter-point finite element approach is still a very effective technique for general three dimensional crack problems in homogeneous anisotropic materials. The expressions of the crack tip asymptotic displacement field are summarized and numerical examples of two and three dimensional crack problems in orthotropic, directionally solidified, and single crystal materials are presented. The stress intensity factors are compared with two-dimensional analytical and numerical solutions available in the literature and with numerical solutions obtained from FRAC3D [1, 2], a three dimensional fracture analysis program using enriched finite elements. Very good agreement is obtained between the different numerical techniques or with the analytical solutions.

scholarly journals Biomechanical evaluation of pin placement of external fixator in treating tranverse tibia fracture: Analysis on first and second cortex of cortical bone

2019 ◽  
Vol 15 (1) ◽  
pp. 75-79
Author(s):  
Muhammad Hanif Hanif Ramlee ◽  
Nur Amalina Zainudin ◽  
Hadafi Fitri Mohd Latip ◽  
Gan Hong Seng ◽  
Evelyn Garcia-Nieto ◽  
...  
Keyword(s):  
Finite Element ◽  
External Fixator ◽  
Bone Fracture ◽  
Three Dimensional ◽  
Tibia Fracture ◽  
Finite Element Software ◽  
Tibia Bone ◽  
Optimum Stability ◽  
Ct Data ◽  
The Stability

Biomechanical perspective of external fixator is one of the greatest factor to consider in successfully treating bone fracture. This is due to the fact that mechanical behavior of the structure can be analyzed and optimized in order to avoid mechanical failure, increase bone fracture healing rate and prevent pre-term screw loosening. There are three significant factors that affect the stability of external fixator which are the placement of pin at the bone, configuration and components of external fixator. These factors lead to one question: what is the optimum pin placement in which exerts optimum stability? To date, literature on above mentioned factors is limited. Therefore, we conducted a study to evaluate the uniplanar-unilateral external fixator for two different pin placement techniques in treating transverse tibia fracture via finite element method. The study was started off with the development of transverse tibia fracture using Mimics software. Computed tomography (CT) data image was utilized to develop three dimensional tibia bone followed by crafting fracture on the bone. Meanwhile, the external fixator was developed using SolidWork software. Both tibia bone and external fixator were meshed in 3-matic software with triangular mesh element. Simulation of this configuration was took place in a finite element software, Marc.Mentat software. A load of 400 N was applied to the proximal tibia bone in order to simulate stance phase of a gait cycle.  From the findings, the pin placement at the second cortex of bone provided optimum stability in terms of stress distribution and displacement, which should be considered for better treatment for transverse tibia fracture. On the other hand, the pin placement at first cortex should be avoided to prevent many complications.

Research on Mesh Optimization of the Finite Element Calculation about Three-Dimensional Foundation Pit

2012 ◽  
Vol 487 ◽  
pp. 855-859
Author(s):  
Shi Lun Feng ◽  
Yu Ming Zhou ◽  
Pu Lin Li ◽  
Jun Li ◽  
Zhi Yong Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Mesh Optimization ◽  
Design Calculation ◽  
Foundation Pit ◽  
3D Design ◽  
Finite Element Software ◽  
Core Language ◽  
Grid Division

Abaqus finite element software can implement three-dimensional excavation design calculation, so authors used Python of Abaqus core language made the 3D design of foundation pit supporting program come ture and also did intensive study of mesh optimization during the process. Authors also did intensive comparison and analysis about grid division of the complex geometry foundation pit, through a regularization partion about a variety of special-shaped pit, we made the automatic division about the structural grid of all kinds of shapes foundation pit successful. On this basis, we achieved better calculation effects of the model. The article will introduce problems about optimization of grid in procedure.

Modeling of Thermoplastic Materials for the Process-Simulation of Press-Fit Interconnections on Moulded Interconnected Devices

2012 ◽  
Vol 134 (3) ◽  
Author(s):  
Thomas Fellner ◽  
Elena Zukowski ◽  
Jürgen Wilde ◽  
H. Kück ◽  
H. Richter ◽  
...  
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Base Material ◽  
Creep Model ◽  
Assembly Process ◽  
Temperature Dependent ◽  
Reliability Modeling ◽  
Finite Element Software ◽  
Press Fit ◽  
Temperature Loads

This investigation is aimed at the modeling of both the fabrication process and the reliability of press-fit interconnections on moulded interconnect devices (MID). These are multifunctional three-dimensional substrates, produced by thermoplastic injection moulding for large-series applications. The assembly process and subsequently the durability of press-fit interconnections has been modeled and proved with a finite element software. Especially, a simulation tool for process optimizations was created and applied. In order to obtain realistic results, a creep model for the investigated base material, a liquid-crystal polymer (LCP), was generated and verified by experiments. Required friction coefficients between metal pin and base material were determined by adapting simulations and experiments. Retention forces of pins pressed into substrate holes during as well after the assembly process, and after temperature loads were predicted by simulations. Additionally, the decreasing extraction forces over time due to creep in the thermoplastic base material have been predicted for different storage temperatures as well with finite element analyses. Following, the numerical results of the process and reliability modeling were verified by experiments. It is concluded that the behavior of the mechanical contact of the pin-substrate system, can be suitably described time- and temperature-dependent.

Optimal Design of the Large-Diameter Spinning Torispherical Head

2012 ◽  
Vol 544 ◽  
pp. 194-199
Author(s):  
Di Zhang ◽  
Shui Ping Sheng ◽  
Zeng Liang Gao
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Large Diameter ◽  
General Purpose ◽  
Design Tool ◽  
Crown Area ◽  
Finite Element Software ◽  
The Stability

Two important parameters of torispherical head that are (interior radius of spherical crown area) and r (interior radius of transition corner) have been optimized by the module of the large general-purpose finite-element software ANSYS, targeting the strength and stability of the head. This paper provides an optimized torispherical head, which improves the stability of the edge of the head with acceptable strength of the head. The procedure is generally applicable as a design tool for optimal design.

Effect of Pile-Soil-Structure Interaction on the Cable-Stayed Bridge in Response to the Earthquake

2014 ◽  
Vol 539 ◽  
pp. 731-735 ◽  
Author(s):  
Yu Chen
Keyword(s):  
Finite Element ◽  
Seismic Response ◽  
Soil Structure ◽  
Response Spectrum ◽  
Three Dimensional ◽  
Soil Structure Interaction ◽  
Structure Interaction ◽  
Finite Element Software ◽  
Cable Stayed Bridge ◽  
Three Dimensional Finite Element

In this thesis, based on the design of a 140+90m span unusual single tower and single cable plane cable-stayed bridge, free vibration characteristics and seismic response are investigated; three dimensional finite element models of a single tower cable-stayed bridge with and without the pile-soil-structure interaction are established respectively by utilizing finite element software MIDAS/CIVIL, seismic response of Response spectrum and Earthquake schedule are analyzed respectively and compared. By the comparison of the data analysis, for small stiffness span cable-stayed bridge, the pile-soil-structure interaction can not be ignored with calculation and analysis of seismic response.

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