scholarly journals Numerical Modeling on Crack Propagation Based on a Multi-Grid Bond-Based Dual-Horizon Peridynamics

Mathematics ◽  
2021 ◽  
Vol 9 (22) ◽  
pp. 2848
Author(s):  
Zili Dai ◽  
Jinwei Xie ◽  
Zhitang Lu ◽  
Shiwei Qin ◽  
Lin Wang
Keyword(s):  
Concrete Specimen ◽  
Element Model ◽  
Nonlocal Theory ◽  
Benchmark Problems ◽  
Computational Accuracy ◽  
Notched Specimen ◽  
Volume Correction ◽  
Proposed Model ◽  
Improve Calculation ◽  
Surface Correction

Peridynamics (PD) is a novel nonlocal theory of continuum mechanics capable of describing crack formation and propagation without defining any fracture rules in advance. In this study, a multi-grid bond-based dual-horizon peridynamics (DH-PD) model is presented, which includes varying horizon sizes and can avoid spurious wave reflections. This model incorporates the volume correction, surface correction, and a technique of nonuniformity discretization to improve calculation accuracy and efficiency. Two benchmark problems are simulated to verify the reliability of the proposed model with the effect of the volume correction and surface correction on the computational accuracy confirmed. Two numerical examples, the fracture of an L-shaped concrete specimen and the mixed damage of a double-edged notched specimen, are simulated and analyzed. The simulation results are compared against experimental data, the numerical solution of a traditional PD model, and the output from a finite element model. The comparisons verify the calculation accuracy of the corrected DH-PD model and its advantages over some other models like the traditional PD model.

Analysis of Shear-critical reinforced concrete columns under variable axial load

2022 ◽  
pp. 1-24
Author(s):  
Dimitrios K. Zimos ◽  
Panagiotis E. Mergos ◽  
Vassilis K. Papanikolaou ◽  
Andreas J. Kappos
Keyword(s):  
Reinforced Concrete ◽  
Axial Load ◽  
Shear Failure ◽  
Progressive Collapse ◽  
Full Range ◽  
Element Model ◽  
Independent Verification ◽  
Lateral Response ◽  
Proposed Model ◽  
Compressive Axial Load

Older existing reinforced concrete (R/C) frame structures often contain shear-dominated vertical structural elements, which can experience loss of axial load-bearing capacity after a shear failure, hence initiating progressive collapse. An experimental investigation previously reported by the authors focused on the effect of increasing compressive axial load on the non-linear post-peak lateral response of shear, and flexure-shear, critical R/C columns. These results and findings are used here to verify key assumptions of a finite element model previously proposed by the authors, which is able to capture the full-range response of shear-dominated R/C columns up to the onset of axial failure. Additionally, numerically predicted responses using the proposed model are compared with the experimental ones of the tested column specimens under increasing axial load. Not only global, but also local response quantities are examined, which are difficult to capture in a phenomenological beam-column model. These comparisons also provide an opportunity for an independent verification of the predictive capabilities of the model, because these specimens were not part of the initial database that was used to develop it.

An Investigation Into the Upper Arm Deformation Under Inflatable Cuff

2008 ◽  
Author(s):  
H. Lan ◽  
A. M. Al-Jumaily ◽  
A. Lowe
Keyword(s):  
Finite Element ◽  
Soft Tissues ◽  
Element Model ◽  
Upper Arm ◽  
Inflatable Cuff ◽  
Proposed Model ◽  
Materials Used ◽  
Tissue Deformations ◽  
Visible Human ◽  
Collapse Process

The human upper arm is simulated using a nonlinear geometrical and physical model. To create a more realistic simulation, the geometry of the model is based on the visible human body dataset. The model consists of four parts, humerus, brachial artery, muscle, and other soft tissues. All the materials used in this model are assumed to be incompressible and hyperelastic. The unique properties of each material are specified and described. Incorporating all of these facts, a finite element model is developed using the commercial programme ABAQUS®. The upper arm tissues’ deformations and artery collapse process under compression are simulated in this model. The proposed model has the potential to simulate the tissue deformations under inflatable cuffs exposed to arm movements.

A Least-Loss Algorithm for a Bi-Objective One-Dimensional Cutting-Stock Problem

2019 ◽  
Vol 6 (2) ◽  
pp. 1-19 ◽  
Author(s):  
Hesham K. Alfares ◽  
Omar G. Alsawafy
Keyword(s):  
Real Life ◽  
Cutting Stock Problem ◽  
Cutting Stock ◽  
Benchmark Problems ◽  
Standard Size ◽  
One Dimensional ◽  
Small Item ◽  
Proposed Model ◽  
Trim Loss ◽  
Industrial Problem

This article presents a new model and an efficient solution algorithm for a bi-objective one-dimensional cutting-stock problem. In the cutting-stock—or trim-loss—problem, customer orders of different smaller item sizes are satisfied by cutting a number of larger standard-size objects. After cutting larger objects to satisfy orders for smaller items, the remaining parts are considered as useless or wasted material, which is called “trim-loss.” The two objectives of the proposed model, in the order of priority, are to minimize the total trim loss, and the number of partially cut large objects. To produce near-optimum solutions, a two-stage least-loss algorithm (LLA) is used to determine the combinations of small item sizes that minimize the trim loss quantity. Solving a real-life industrial problem as well as several benchmark problems from the literature, the algorithm demonstrated considerable effectiveness in terms of both objectives, in addition to high computational efficiency.

Nonlinear Large Deformation of Graphene Sheets Using a Nonlocal-Based ANCF Method

2019 ◽  
Vol 11 (04) ◽  
pp. 1950037 ◽  
Author(s):  
Qingtao Wang ◽  
Zhen Zhao ◽  
Yang Zhang ◽  
Zhaojun Pang ◽  
Fuzhou Niu
Keyword(s):  
Large Deformation ◽  
Nonlocal Elasticity Theory ◽  
Nonlocal Theory ◽  
Elastic Force ◽  
Graphene Sheets ◽  
Deformation Problem ◽  
Proposed Model ◽  
Large Deformation Problem ◽  
Loading Modes ◽  
Definition Of

A novel nonlinear model of single-layered graphene sheets (SLGSs) subject to large deformation is proposed using the absolute nodal coordinate formulation (ANCF) and the nonlocal elasticity theory. The geometrical definition of SLGSs is described by ANCF thin plate element while the strain energy is expressed by nonlocal theory. Then, the formulation of elastic force and the Jacobian of the elastic force is derived. We verify the proposed model by comparing the results with other published results and conduct corresponding numerical case study to clarify the influence of boundary conditions (BCs), nonlocal parameters, side length and aspect ratio. Large deformation problem of SLGSs with several BCs and different loading modes are simulated to study the mechanical nonlinearity of the SLGSs.

Advanced joint slip model for single-angle bolted connections considering various effects

2020 ◽  
Vol 23 (10) ◽  
pp. 2121-2135
Author(s):  
Ahmed Hussain Ali Abdelrahman ◽  
Yao-Peng Liu ◽  
Siu-Lai Chan
Keyword(s):  
Plate Thickness ◽  
Direct Analysis ◽  
Element Model ◽  
Fe Model ◽  
Slip Model ◽  
Transmission Towers ◽  
Slip Effects ◽  
Proposed Model ◽  
Full Scale Tests ◽  
The Cost

Latticed structures are commonly used in transmission towers due to lightweight, fast fabrication, and easy installation, but they generally experience more complicated structural behaviors. The full-scale tests on transmission towers have revealed large discrepancies between the numerical simulation and experimental results because the significant joint slip effects have not well considered in the former. The existing joint slip models were so simple that many key parameters had not been taken into account. Thus, a comprehensive joint slip model is proposed in this article for better prediction and design of tower structures. First, a full-detailed finite element model based on ABAQUS incorporating more realistic parameters for a typical joint is developed and calibrated by the experimental data from the literature. Furthermore, the proposed FE model is used for parametric study of joint behaviors with considerations of bolt pretension, friction at contact face, angle sizes and plate thickness, steel and bolt grades, number of bolts, and hole tolerance. Finally, an advanced joint slip model is provided for further incorporation in the second-order direct analysis of transmission towers. This work is limited in the literature and will significantly improve safety and enhance the cost-efficiency of tower design. The proposed model shows high accuracy and can be simply determined by joint details in line with the component method specified in Eurocode 3-1-8.

Experimental Validation of Role of Cut-Out Parameters on Modal Responses of Laminated Composite — A Coupled FE Approach

2020 ◽  
Vol 12 (06) ◽  
pp. 2050068 ◽  
Author(s):  
Hukum Chand Dewangan ◽  
Subrata Kumar Panda ◽  
Nitin Sharma
Keyword(s):  
Composite Structure ◽  
Laminated Composite ◽  
Element Model ◽  
Composite Panel ◽  
Design Constraint ◽  
Isoparametric Finite Element ◽  
Proposed Model ◽  
Free Vibration Frequency ◽  
First Time

The free vibration frequency responses of the laminated composite structure with a cut-out of variable shapes (square/circular/elliptical), position (center/eccentric) and orientation (parallel/inclined) are investigated for the first time in this research including geometrical shapes. The eigenvalues are obtained computationally for the cut-out borne structure via a linear isoparametric finite element model of the composite structure in association with cubic-order of displacement kinematics. Also, a coupled code is prepared in MATLAB environment by joining the higher-order formulation and the simulation model (ABAQUS) to achieve the generic form to investigate the influential cut-out parameter (shape, size and position) on their eigenvalues. Further, a series of experimentations are carried out using the cut-out borne composite panel and compared with the computational frequency, including the experimental properties. Finally, the key behavior is surveyed through different kinds of numerical examples for various design constraint parameters including the cut-out relevant factors (shape, position and orientation) to show the subsequent inclusiveness of the proposed model.

Extenics Decision Model for Evaluating Mechanical Joint Interface of Reconfigurable Machine Tools

2011 ◽  
Vol 311-313 ◽  
pp. 1972-1976
Author(s):  
Li Mei Ma ◽  
Jian Yong Li ◽  
Wen Sheng Xu ◽  
Ding Lei Wang
Keyword(s):  
Machine Tools ◽  
Decision Model ◽  
Element Model ◽  
Performance Criteria ◽  
Joint Interface ◽  
Mechanical Joint ◽  
Proposed Model ◽  
Interface System ◽  
Evaluation Approaches ◽  
The Relationship

In Reconfigurable machine tools (RMTs), the reconfiguration only occurs at the mechanical interface system composed of mechanical modules, joining mechanisms, or adapter mechanisms, and their reconfigurability degree depends strongly on the properties of its module interfaces. This paper investigates the performance criteria influencing the reconfigurability of module joint interfaces. An Extenics Element Model (EEM) method is proposed to model the component module of RMTs, module interfaces and the relationship between mechanical modules. Furthermore, the evaluation values are determined based on the Simple Dependent Function (SDF) to evaluate the reconfigurability of different joint interfaces. Finally, two types of joint interfaces between worktable and slide are presented to verify the proposed model and evaluation approaches.

Modeling Method of Assembled Structure Coupling the Characteristics of the Joints

2012 ◽  
Vol 468-471 ◽  
pp. 2141-2148
Author(s):  
Tie Neng Guo ◽  
Xue Li Yu ◽  
Fu Ping Li ◽  
Li Gang Cai ◽  
Ya Hui Cui
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Element Model ◽  
Experimental Investigations ◽  
Beam Elements ◽  
Joint Characteristics ◽  
Proposed Model ◽  
Mechanics Analysis ◽  
Stiffness And Damping ◽  
The Finite Element Model

Mechanical properties of the joints have impacted on the whole mechanical characteristics. Coupling the joint characteristics in the modeling of the machine tool is an important problem in machine mechanics analysis. In order to solve the joint modellings in the assembled structure, this paper presents a new method to creat beam elements between two symmetrical nodes on the contact surface of the joint. The stiffness and damping matrices of the elements are valuated according to the characteristics of the joint. To validate the accuracy of the proposed method, the modeling of an assembled structure with and without the joints is obtained and some corresponding experimental investigations are implemented. The error between the simulated and experimental results of the finite element model is less than 8.8%, while the error of the contact model often used in the existing literatures is one times bigger than the proposed model.

A four-node membrane element model with bending modification for one-step algorithm for bus rollover impact

2015 ◽  
Vol 32 (3) ◽  
pp. 607-620 ◽  
Author(s):  
Jingxin Na ◽  
Tong Wang ◽  
Changfeng Wu ◽  
Yakun Yan
Keyword(s):  
Engineering Application ◽  
Element Model ◽  
Bending Moments ◽  
Membrane Element ◽  
Computational Accuracy ◽  
Content Type ◽  
One Step ◽  
Internal Forces ◽  
Step Algorithm ◽  
The One

Purpose – The purpose of this paper is to propose a new four-node membrane element model with bending modification based on the equilibrium principle of element nodal internal forces and bending moments for the application of the one-step algorithm for bus rollover collision. And it can be concluded whether the proposed four-node membrane element model has practical value in engineering application or not. Design/methodology/approach – Based on the equilibrium principle of element nodal internal forces and bending moments, the paper puts forward a four-node membrane element model with bending modification. A case study on the rollover of a typical bus body section is carried out by using the one-step algorithm for bus rollover collision to verify the effectiveness of the proposed element model. Findings – For the simulation of bus rollover collision, the computational accuracy can be guaranteed, meanwhile, the calculated amount is much smaller than the shell element, and computational efficiency is improved significantly. Originality/value – The proposed four-node membrane element model is used for the simulation of bus rollover collision for the first time. It holds the advantage of high computational efficiency of membrane element, and the computational accuracy is improved as well. In conclusion, it has some practical value in engineering application.

A Finite Element Model for Elastic and Slip Responses of Fusion Magnets

1980 ◽  
Vol 102 (2) ◽  
pp. 219-225
Author(s):  
T. Y. Chang ◽  
H. Suzuki ◽  
M. Reich
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Bonding Strength ◽  
Element Model ◽  
Type Model ◽  
Shear Stresses ◽  
Homogenization Procedure ◽  
Numerical Examples ◽  
Proposed Model ◽  
Interlayer Slip

A finite element model to simulate the elastic and slip responses of fusion magnets under operating loads is proposed. To represent the elastic actions, a material homogenization procedure based on the existing composite technology was applied to obtain the effective stress strain relations for the heterogeneous, laminated magnets. In addition, a friction-type model was utilized to simulate the interlayer slip of the magnets when the shear stresses reach the bonding strength of the adhesives. Numerical examples are given to demonstrate the applicability of the proposed model.

Sign in / Sign up

Export Citation Format

Share Document