scholarly journals Gradient Nonlocal Enhanced Microprestress-Solidification Theory and Its Finite Element Implementation

2021 ◽  
Vol 8 ◽  
Author(s):  
Teng Tong ◽  
Changqing Du ◽  
Xiaofan Liu ◽  
Siqi Yuan ◽  
Zhao Liu
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Deformation Gradient ◽  
Damage Model ◽  
Reinforced Concrete Beams ◽  
Chain Model ◽  
Finite Element Software ◽  
Order Deformation ◽  
Implicit Solver

Time-dependent responses of cracked concrete structures are complex, due to the intertwined effects between creep, shrinkage, and cracking. There still lacks an effective numerical model to accurately predict their nonlinear long-term deflections. To this end, a computational framework is constructed, of which the aforementioned intertwined effects are properly treated. The model inherits merits of gradient-enhanced damage (GED) model and microprestress-solidification (MPS) theory. By incorporating higher order deformation gradient, the proposed GED-MPS model circumvents damage localization and mesh-sensitive problems encountered in classical continuum damage theory. Moreover, the model reflects creep and shrinkage of concrete with respect to underlying moisture transport and heat transfer. Residing on the Kelvin chain model, rate-type creep formulation works fully compatible with the gradient nonlocal damage model. 1-D illustration of the model reveals that the model could regularize mesh-sensitivity of nonlinear concrete creep affected by cracking. Furthermore, the model depicts long-term deflections and cracking evolutions of simply-supported reinforced concrete beams in an agreed manner. It is noteworthy that the gradient nonlocal enhanced microprestress-solidification theory is implemented in the general finite element software Abaqus/Standard with the implicit solver, which renders the model suitable for large-scale creep-sensitive structures.

scholarly journals A Large-Deformation Gradient Damage Model for Single Crystals Based on Microdamage Theory

2020 ◽  
Vol 10 (24) ◽  
pp. 9142
Author(s):  
Ozgur Aslan ◽  
Emin Bayraktar
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Flow Resistance ◽  
Large Deformations ◽  
Deformation Gradient ◽  
Damage Model ◽  
Anisotropic Damage ◽  
Finite Element Software ◽  
Mesh Dependency ◽  
Micromorphic Theory

This work aims at the unification of the thermodynamically consistent representation of the micromorphic theory and the microdamage approach for the purpose of modeling crack growth and damage regularization in crystalline solids. In contrast to the thermodynamical representation of the microdamage theory, micromorphic contribution to flow resistance is defined in a dual fashion as energetic and dissipative in character, in order to bring certain clarity and consistency to the modeling aspects. The approach is further extended for large deformations and numerically implemented in a commercial finite element software. Specific numerical model problems are presented in order to demonstrate the ability of the approach to regularize anisotropic damage fields for large deformations and eliminate mesh dependency.

Research on Thermally Induced Deformation of Reinforcing Plate Based on Finite Element Simulation

2012 ◽  
Vol 197 ◽  
pp. 139-143
Author(s):  
Hua Bai ◽  
Yi Du Zhang
Keyword(s):  
Finite Element ◽  
Ambient Temperature ◽  
Finite Element Simulation ◽  
Temperature Change ◽  
Large Scale ◽  
Machining Process ◽  
Reinforcement Structure ◽  
Thermally Induced ◽  
Finite Element Software ◽  
Element Simulation

The change of ambient temperature will cause deformation during the machining process of large-scale aerospace monolithic component. Based on finite element simulation, thermally induced deformation of reinforcing plate is studied in such aspects as reinforcement structure, clamping method and temperature change, and contact function in finite element software is used to simulate the unilateral constraint between workpiece and worktable. The results indicate that reinforcing plate will produce warping deformation due to the change of ambient temperature. Different reinforcement structures and clamping methods have important influence on the deformation positions and degrees, and the deformation is proportional to the temperature change.

Three-Dimensional FEM Simulation of the Ship-Bridge Collision

2013 ◽  
Vol 405-408 ◽  
pp. 3243-3247
Author(s):  
Wei Su ◽  
Ying Sun ◽  
Shi Qing Huang ◽  
Ren Huai Liu
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Reference Values ◽  
Large Scale ◽  
Three Dimensional ◽  
Fem Simulation ◽  
Structural Safety ◽  
Fem Model ◽  
Finite Element Software

In this paper, the structural safety of the Niuwan Bridge subjected to vessel collision is investigated by the large-scale commercial finite element software ANSYS. A whole FEM model is built and a reasonable analysis and illustration for taking the value of vessel-collision forces is presented. Additionally, under the premise of reasonable simulation of the boundary conditions, the effects of the support abutments, the prestress and the carloads are considered. The analysis results have certain reference values for the anti-collision and reinforcement of bridges.

Three-Dimensional Seismic Analysis on Reactor Structure

2010 ◽  
Author(s):  
Naibin Jiang ◽  
Feng-gang Zang ◽  
Li-min Zhang ◽  
Chuan-yong Zhang
Keyword(s):  
Finite Element ◽  
Large Scale ◽  
Seismic Analysis ◽  
Three Dimensional ◽  
Element Model ◽  
Earthquake Excitation ◽  
Finite Element Software ◽  
Reactor Structure ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The seismic analysis on reactor structure was performed with a new generation of finite element software. The amount of freedom degree of the model was more than twenty millions. The typical responses to operational basis earthquake excitation were given. They are larger than those with two-dimensional simplified finite element method, and the reasons of this phenomenon were analyzed. The feasibility of seismic analysis on large-scale three-dimensional finite element model under existing hardware condition was demonstrated, so some technological reserves for dynamic analysis on complicated equipments or systems in nuclear engineering are provided.

scholarly journals Long-Term Settlement of High Concrete-Face Rockfill Dam by Field Monitoring and Numerical Simulation

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Xinjie Zhou ◽  
Xinjian Sun ◽  
Junxing Zheng ◽  
Haoyuan Jiang ◽  
Yongye Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Creep Deformation ◽  
Deformation Behavior ◽  
Finite Element Software ◽  
Rockfill Materials ◽  
Stress And Deformation ◽  
Long Term Performance ◽  
Term Performance ◽  
Concrete Face

High concrete-face rockfill dams (CFRDs) with heights of over 100 m have been quickly developed in recent years. The self-weight of rockfill materials causes creep deformation of the dam body. However, the creep analysis method of high CFRDs in finite element software is few, and sometimes, it can also not reflect the long-term performance of high CFRDs well. Therefore, it is necessary to carry out the secondary development in finite element software. This study developed a subroutine that can run in Finite Element Method (FEM) platform ABAQUS to simulate long-term creep deformation behavior of the rockfill materials more accurately. Then, a displacement back-analysis for parameters, based on the Xujixia high CFRD project, is performed by the neural network response surface method (BP-MPGA/MPGA). Remarkable agreements are observed between simulation and field monitoring results. The calibrated FEM model is used to predict stress and deformation behavior of the Xujixia high CFRD after three years of operation period. The result indicates that rockfill creep deformation has a significant impact on stress and deformation of the high CFRD during the operation. This research may predict long-term performance using FEM in the design stage for high CFRDs.

scholarly journals A Braked Tail Cover Separation Concept and Simulation of Separation Process

2018 ◽  
Vol 166 ◽  
pp. 02003
Author(s):  
Mei Huang ◽  
Yi Jiang ◽  
Boman Wang
Keyword(s):  
Finite Element ◽  
Working Conditions ◽  
Large Scale ◽  
Rocket Engine ◽  
Separation Process ◽  
Separation Device ◽  
Internal Ballistic ◽  
Finite Element Software ◽  
New Type

Large-scale missiles are generally catapulted by the ejector. And a tail cover is used to protect the first stage rocket engine. When the missile reaches the predetermined height, the tail cover should be separated timely so that the engine can work properly. In this paper, a braked tail cover separation concept is proposed. And a new type of tail cover separation device is designed according to the concept. Firstly, the forces analysis and the internal ballistic simulation of ejection are conducted before setting working conditions. And then, the finite element software Abaqus is adopted to achieve the simulation of tail cover separation process. Through analyzing the obtained results, it’s concluded that the braked tail cover separation concept is feasible. Moreover, the influence of material changes on the braking effects is also studied.

The Finite Element Analysis and Comparison of Wind Turbine Tower under Static Wind Load and Fluctuating Wind Load

2013 ◽  
Vol 446-447 ◽  
pp. 733-737
Author(s):  
Chi Chen ◽  
Hao Yuan Chen ◽  
Tian Lu
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Wind Turbine ◽  
Modal Analysis ◽  
Large Scale ◽  
Wind Load ◽  
Element Analysis ◽  
Finite Element Software ◽  
Wind Turbine Tower ◽  
Fluctuating Wind

In this paper, a 1.5 MW wind turbine tower in Dali, Yunnan Province is used as the research object, using large-scale finite element software Ansys to carry on the dynamic analysis. These natural frequencies and natural vibration type of the first five of tower are obtained by modal analysis and are compared with natural frequency to determine whether the resonance occurs. Based on the modal analysis, the results of the transient dynamic analysis are obtained from the tower, which is loaded by the static wind load and fluctuating wind load in two different forms. By comparing the different results, it provides the basis for the dynamic design of wind turbine tower.

Discussion of Different Methods of Strengthening Masonry Walls with Constructional Column

2012 ◽  
Vol 226-228 ◽  
pp. 1098-1101
Author(s):  
Cheng Wang ◽  
Yong Kun Luo ◽  
Xiao Long Xu
Keyword(s):  
Finite Element ◽  
Seismic Performance ◽  
Large Scale ◽  
Rapid Development ◽  
Masonry Wall ◽  
Earthquake Resistance ◽  
Masonry Walls ◽  
Finite Element Software ◽  
Engineering Discipline ◽  
Constructional Column

With the rapid development of economy and the civil engineering discipline, the seismic performance of existing masonry wall can't satisfy the codes and regional seismic requirements. As a result, strengthening the earthquake resistance of it is put on the agenda. Using large-scale finite element software-abaqus, this paper analyzes different methods of strengthening masonry walls by constructional columns. Under the premise of the cross area of the columns used to reinforce is identical, it shows that the wall strengthened by bilateral constructional columns has a better seismic performance than by unilateral constructional column. The ductility coefficient of the former increases 49.4% than the original masonry, while the latter increases 26.3%. The bilateral constructional column could significantly improve the integrity and ductility of the masonry wall, so does the seismic performance. It has engineering sense for the strengthening work.

The Finite Element Analysis on Axial Tensile Bearing Capacity of Round Steel-Tubes Reinforced with CFRP Sheets

2011 ◽  
Vol 368-373 ◽  
pp. 1595-1599
Author(s):  
Xiu Li Wang ◽  
Jun Jie Li
Keyword(s):  
Finite Element ◽  
Bearing Capacity ◽  
Large Scale ◽  
Steel Tubes ◽  
Element Analysis ◽  
Cfrp Sheets ◽  
Finite Element Software ◽  
Axial Tensile ◽  
The Finite Element Analysis ◽  
Circumferential Reinforcement

The numerical simulation calculation on round steel-tubes reinforced with CFRP sheets was done through the large-scale finite element software ANSYS. In this research, four factors were comparatively analyzed so as to obtain the influence of them on ultimate axial tensile bearing capacity of steel-tubes. These four factors are longitudinal reinforcement length rate , thickness , elastic modulus and circumferential reinforcement ways of CFRP sheets. The results show that the ultimate axial tensile bearing capacity of steel-tubes strengthened with CFRP sheets is enhanced significantly and the reinforcement effect is very good.

The Influence of Soft Soil on the Analysis of Soil-Pile Dynamic Interaction

2011 ◽  
Vol 52-54 ◽  
pp. 1451-1457
Author(s):  
Xu Dong Cheng ◽  
Jie Li ◽  
Yong Wang
Keyword(s):  
Finite Element ◽  
Seismic Design ◽  
Pile Foundation ◽  
Large Scale ◽  
Soft Soil ◽  
Dynamic Interaction ◽  
Finite Element Software ◽  
Ground Treatment ◽  
Calculation Results ◽  
Different Thickness

In the seismic design of pile foundation, current research mainly adopts the theory of auxiliary experiences engineering design methods. In particular ground, the pile must be specially designed to meet the seismic requirements. In this paper, with large scale finite element software ADINA,a 2-d finite element entity model is established to calculate and analyze the influence of soft soil to the dynamic interaction of soft pile-soil under the earthquake. The maximum displacements and acceleration of the measuring points on the pile are analyzed in different thickness and position of the soft soil. Calculation results show that: Soft soil effect the maximal displacement and acceleration of the measuring points on the pile which changed with the different thickness and positions of the soft soil. It should be noticed in the design of pile foundation and ground treatment.

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