Compression of elastic–perfectly plastic microcapsules using micromanipulation and finite element modelling: Determination of the yield stress

2011 ◽  
Vol 66 (9) ◽  
pp. 1835-1843 ◽  
Author(s):  
Ruben Mercadé-Prieto ◽  
Rachael Allen ◽  
David York ◽  
Jon A. Preece ◽  
Ted E. Goodwin ◽  
...  
Keyword(s):  
Finite Element ◽  
Yield Stress ◽  
Finite Element Modelling ◽  
Element Modelling ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

scholarly journals ROTATIONAL STIFFNESS DETERMINATION OF THE SEMI-RIGID TIMBER-STEEL CONNECTION

2017 ◽  
Vol 23 (8) ◽  
pp. 1021-1028
Author(s):  
Tomas GEČYS ◽  
Alfonsas DANIŪNAS
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Bending Moment ◽  
Steel Structures ◽  
Rotational Stiffness ◽  
Element Modelling ◽  
Component Method ◽  
Steel Connection ◽  
Timber Connections

In this research, the component method implementation for determination of the rotational stiffness of timber-steel connection is shown. Component method is one of the most commonly used methods for determination of the bending moment-rotation relation which later may be used in the practical analysis of the connection. The component method is not widely used for the analysis of the semi-rigid timber connections. There are only several investigations previously done on the component method implementation for the timber connections and most of them are based on only one basic component, i.e. timber compression or glued-in steel rod in tension. This article presents a new investigation of rotational stiffness determination algorithm of the semi-rigid timber-steel connection, which is based on the component method. The component method’s mechanical model of the connection combines all components which have influence on the rotational stiffness of the connection. The analysed timber-steel connection is subjected to pure bending. Stiffness coefficients of the steel part components are determined according to the Eurocode 3: design of steel structures Part 1-8: Design of joints. The timber part components are derived from the full-scale laboratory experiments and finite element modelling results, presented in the previous publications of the authors. The presented rotational stiffness determination results are well in line with the experimental and finite element modelling results, published in the previous publications.

A Novel Tool Path Strategy for Modelling Complicated Perpendicular Curved Movements

2019 ◽  
Vol 796 ◽  
pp. 164-174 ◽  
Author(s):  
Bahman Meyghani ◽  
Mokhtar Awang
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Tool Path ◽  
Cnc Machining ◽  
Process Time ◽  
Efficient Tool ◽  
Element Modelling ◽  
Friction Stir ◽  
Tool Paths

Curved surfaces have been widely used in engineering applications such as friction stir welding (FSW), 5 axis CNC machining, and other processes. Therefore, the development of the finite element modelling of the complicated geometries has created a need to determine efficient tool paths. Previous finite element models modelled the single point movement of the tool. However, in industrial applications such as aerospace, mould and die, etc. the movement of the tool is complex. Proper determination of the tool path can lead to substantial savings of the process time, improvement of the workpiece surface quality and the improvement of the tool life, thereby leading to overall cost reduction and higher productivity. This paper presents a new approach for the determination of efficient tool paths in finite element modelling by using ABAQUS® software. VDISP user defined subroutine is used in order to define the complex curved movement of the tool. The results indicate that the method is appropriate for modelling of the tool path, and the tool always has a perpendicular position to the surface. Therefore, the method can be suitable for increasing the application of the finite element modelling in various industries.

Effect of Laminates Orientation on Impact Properties of Fiberglass and Kevlar Composite Panels

2015 ◽  
Vol 808 ◽  
pp. 119-124
Author(s):  
Emilian Ionut Croitoru ◽  
Gheorghe Oancea
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Composite Panel ◽  
Left Wing ◽  
Stress Variation ◽  
Impact Properties ◽  
Element Modelling ◽  
Loading Case ◽  
Multiple Configurations

This paper presents the study of the effect of laminates angle on impact properties of a composite panel made of glass and Kevlar fibers using finite element modelling. In this research, the composite panel consists of a skin panel, specifically the front left wing, from an automotive vehicle having multiple configurations. A distributed pressure on the composite package represents the loading on the selected panel modelled as one uniform distributed abuse loading case and the stress variation within the composite panel for each configuration is determined. The results of these analyses are used for the determination of mathematical models for tensions, longitudinal and shear tensions, as functions of laminate angle for each configuration.

scholarly journals Elastic-Perfectly Plastic Contact of Rough Surfaces: An Incremental Equivalent Circular Model

2021 ◽  
Author(s):  
GF WANG
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Yield Stress ◽  
Contact Area ◽  
Present Model ◽  
Rough Surfaces ◽  
Perfectly Plastic ◽  
Circular Model ◽  
Linear Load ◽  
Elastic Perfectly Plastic

In this paper, an incremental eqivalent contact model is developed for elastic-perfectly plastic solids with rough surfaces. The contact of rough surface is modeled by the accumulation of circular contacts with varying radius, which is estimated from the geometrical contact area and the number of contact patches. For three typical rough surfaces with various mechanical properties, the present model gives accurate predictions of the load-area relation, which are verified by direct finite element simulations. An approximately linear load-area relation is observed for elastic-plastic contact up to a large contact fraction of 15%, and the influence of yield stress is addressed.

Determination of Ultimate Filling Height of Slag Subgrade with FEM Modelling

2012 ◽  
Vol 188 ◽  
pp. 84-89 ◽  
Author(s):  
Bing Gen Zhan ◽  
Yi Dong Ruan ◽  
Ding Han
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Creep Test ◽  
Finite Element Modelling ◽  
Differential Settlement ◽  
Element Modelling ◽  
Filling Height ◽  
Pavement Structures ◽  
Surface Increase

To use slag in high subgrade reasonably and effectively, the filling height limit was investigated. The viscoelasticity parameters of slag in a ascertain graduation were gained by viscoelasticity constitutive model and indoor creep test. The differential settlement values (DSV) of subgrade surface at various filling heights were obtained by the finite element modelling. The research results show that the DSVs on subgrade surface increase with the filling height. According to the effects of DSV on pavement structures, four grades of differential settlement from low to high were divided, the ultimate filling heights of slag were evaluated correspondingly.

scholarly journals Characterization of Material Properties Based on Inverse Finite Element Modelling

2019 ◽  
Author(s):  
Mikdam Jamal ◽  
Michael Morgan
Keyword(s):  
Finite Element ◽  
Yield Stress ◽  
Material Properties ◽  
Modulus Of Elasticity ◽  
Finite Element Modelling ◽  
Material Model ◽  
Hardening Material ◽  
Complex Material ◽  
Element Modelling ◽  
Material Systems

This paper describes a new approach that can be used to determine the mechanical properties of unknown materials and complex material systems. The approach uses inverse finite element modelling (FEM) accompanied with a designed algorithm to obtain the modulus of elasticity, yield stress and strain hardening material constants of an isotropic hardening material model, as well as the material constants of the Drucker-Prager material model (modulus of elasticity, cap yield stress and angle of friction). The algorithm automatically feeds the input material properties data to finite element software and automatically runs simulations to establish a convergence between the numerical loading-unloading curve and the target data obtained from continuous indentation tests using common indenter geometries. A further module was developed to optimise convergence using an inverse FEM analysis interfaced with a non-linear MATLAB algorithm. A sensitivity analysis determined that the dual Spherical and Berkovich (S&B) approach delivered better results than other dual indentation methods such as Berkovich and Vickers (B&V) and Vickers and Spherical (V&S). It was found that better convergence values can be achieved despite a large variation in the starting parameter values and / or material constitutive model and such behaviour reflects the uniqueness of the dual S&B indentation in predicting complex material systems. The study has shown that a robust optimization method based on a non-linear least-squares curve fitting function (LSQNONLIN) within MATLAB and ABAQUS can be used to accurately predict a unique set of elastic plastic material properties and Drucker-Prager material properties. This is of benefit to the scientific investigation of properties of new materials or obtaining the material properties at different location of a part which might be not be similar due to manufacturing processes (e.g. different heating and cooling rates at different locations).

scholarly journals Characterization of Material Properties Based on Inverse Finite Element Modelling

Inventions ◽  
2019 ◽  
Vol 4 (3) ◽  
pp. 40 ◽  
Author(s):  
Jamal ◽  
Morgan
Keyword(s):  
Finite Element ◽  
Yield Stress ◽  
Material Properties ◽  
Modulus Of Elasticity ◽  
Finite Element Modelling ◽  
Material Model ◽  
Hardening Material ◽  
Complex Material ◽  
Element Modelling ◽  
Material Systems

This paper describes a new approach that can be used to determine the mechanical properties of unknown materials and complex material systems. The approach uses inverse finite element modelling (FEM) accompanied with a designed algorithm to obtain the modulus of elasticity, yield stress and strain hardening material constants of an isotropic hardening material model, as well as the material constants of the Drucker–Prager material model (modulus of elasticity, cap yield stress and angle of friction). The algorithm automatically feeds the input material properties data to finite element software and automatically runs simulations to establish a convergence between the numerical loading–unloading curve and the target data obtained from continuous indentation tests using common indenter geometries. A further module was developed to optimise convergence using an inverse FEM analysis interfaced with a non-linear MATLAB algorithm. A sensitivity analysis determined that the dual spherical and Berkovich (S&B) approach delivered better results than other dual indentation methods such as Berkovich and Vickers (B&V) and Vickers and spherical (V&S). It was found that better convergence values can be achieved despite a large variation in the starting parameter values and/or material constitutive model and such behaviour reflects the uniqueness of the dual S&B indentation in predicting complex material systems. The study has shown that a robust optimization method based on a non-linear least-squares curve fitting function (LSQNONLIN) within MATLAB and ABAQUS can be used to accurately predict a unique set of elastic plastic material properties and Drucker–Prager material properties. This is of benefit to the scientific investigation of properties of new materials or obtaining the material properties at different locations of a part which may be not be similar because of manufacturing processes (e.g., different heating and cooling rates at different locations).

Elastic-Perfectly Plastic Contact of Rough Surfaces: An Incremental Equivalent Circular Model

2021 ◽  
pp. 1-19
Author(s):  
Xuan-Ming Liang ◽  
Yue Ding ◽  
Yan Duo ◽  
Weike Yuan ◽  
Gangfeng Wang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Yield Stress ◽  
Contact Area ◽  
Present Model ◽  
Rough Surfaces ◽  
Perfectly Plastic ◽  
Circular Model ◽  
Linear Load ◽  
Elastic Perfectly Plastic

Abstract In this paper, an incremental equivalent contact model is developed for elastic-perfectly plastic solids with rough surfaces. The contact of rough surface is modeled by the accumulation of circular contacts with varying radius, which is estimated from the geometrical contact area and the number of contact patches. For three typical rough surfaces with various mechanical properties, the present model gives accurate predictions of the load-area relation, which are verified by direct finite element simulations. An approximately linear load-area relation is observed for elastic-plastic contact up to a large contact fraction of 15%, and the influence of yield stress is addressed.

scholarly journals Analysis and Finite Element Modelling of Water Flow in Concrete

2018 ◽  
Author(s):  
Miklós Pap ◽  
András Mahler ◽  
Salem Georges Nehme
Keyword(s):  
Finite Element ◽  
Water Flow ◽  
Finite Element Modelling ◽  
Water Retention ◽  
Soil Mechanics ◽  
Water Retention Curve ◽  
Depth Of Penetration ◽  
Retention Curve ◽  
Element Modelling

Due to the construction of underground structures and hazardous waste storages, understanding and modelling of seepage in concrete has become an important issue in life-span analyses. The theories and calculation methods of unsaturated soil mechanics provide an opportunity to analyze water flow in other types of porous media (e.g. concrete) as well. This study deals with the determination of the permeability for unsaturated and saturated concrete and modelling the water flow in concrete. The direct measurement of the saturated permeability, the preparation of the drying water retention curve and determination of the depth of penetration of water under pressure are involved in the series of tests. For the fitting method of the experimental water retention curves were used Fredlund and Xing (1994) and van Genuchten (1980) model. The theory of lateral shift was applied to estimate the wetting water retention curve from the drying WRC. Thus, we could calculate the unsaturated permeability functions with Fredlund et al. (1994) and van Genuchten (1980) model. The finite element modelling of the standard test for watertightness were performed with Midas GTS using the measured and calculated unsaturated property functions.

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