Design and analysis of large deformation continuous elastoplastic manufacturing processes via a steady displacement-based formulation

1998 ◽  
Author(s):  
D. Balagangadhar ◽  
D. Tortorelli
Keyword(s):  
Large Deformation ◽  
Manufacturing Processes ◽  
Displacement Based

Simulation of a Cantilevered Thin-Elastic Plate with Large Deformation Subjected to Axial Flow

2014 ◽  
Vol 1065-1069 ◽  
pp. 2069-2075
Author(s):  
Wei Bin Hong ◽  
Chang Qing Guo ◽  
Ye Zhou Sheng
Keyword(s):  
Flow Velocity ◽  
Large Deformation ◽  
Elastic Plate ◽  
Stokes Equations ◽  
Axial Flow ◽  
Navier Stokes ◽  
Thin Elastic Plate ◽  
Two Dimensional ◽  
Vibration Responses ◽  
Displacement Based

The instability and dynamics behavior of a cantilevered thin-elastic plate with large deformation subjected to axial flow is studied numerically. The structural dynamics equation is discretized by isoparametric displacement-based finite, and the motion of a continuous fluid domain is governed by two-dimensional incompressible viscous Navier-Stokes equations, which discretized by finite volume method. The two-dimensional numerical model of two-way fluid-structure coupling is established combined with moving mesh technology, realizing the interaction of thin-elastic plate and axial fluid. Firstly, under given different flow velocity, the stability of limit-cycle oscillations has been studied through Hopf bifurcation, time trace, vibration responses. Secondly, the fluid domain features are analyzed qualitatively by separately comparing with vorticity under given different flow velocity, and cloud diagram of pressure and velocity are also analyzed at U=3.6m/s.

F-Bar Aided Edge-Based Smoothed Finite Element Method with 4-Node Tetrahedral Elements for Static Large Deformation Elastoplastic Problems

2019 ◽  
Vol 16 (05) ◽  
pp. 1840010 ◽  
Author(s):  
Yuki Onishi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Large Deformation ◽  
Element Formulation ◽  
Tetrahedral Elements ◽  
Smoothed Finite Element Method ◽  
New Type ◽  
Displacement Based ◽  
Edge Based ◽  
Element Method

A new type of smoothed finite element method (S-FEM), F-barES-FEM-T4, is demonstrated in static large deformation elastoplastic cases. F-barES-FEM-T4 combines the edge-based S-FEM (ES-FEM) and the node-based S-FEM (NS-FEM) for 4-node tetrahedral (T4) elements with the aid of the F-bar method in order to resolve the major issues of Selective ES/NS-FEM-T4. As well as most of the other S-FEMs, F-barES-FEM-T4 inherits pure displacement-based formulation and thus has no increase in DOF. Moreover, the cyclic smoothing procedure introduced in F-barES-FEM-T4 is effective to adjust the smoothing level so that pressure checkerboarding (oscillation) is suppressed reasonably. Some examples of static large deformation analyses for elastoplastic materials proof the excellent performance of F-barES-FEM-T4 in contrast to the conventional hybrid T4 element formulation.

Dynamic Mechanical Behavior of Titanium Ti-6Al-4V at Transient Large Deformation Manufacturing Processes

2007 ◽  
Author(s):  
J. Sun ◽  
Y. B. Guo
Keyword(s):  
Flow Stress ◽  
Mechanical Behavior ◽  
Large Deformation ◽  
Large Deformations ◽  
Model Parameters ◽  
Manufacturing Processes ◽  
Strain Rates ◽  
Dynamic Mechanical ◽  
Dynamic Mechanical Behavior ◽  
Jc Model

Titanium Ti-6Al-4V alloy has been widely used in the aerospace, biomedical, automobile and petroleum industries. However, Ti-6Al-4V is a typical difficult-to-process material owning to its unique physical and mechanical properties which are characterized by low thermal conductivity, low modulus of elasticity, and high yield strength at elevated temperatures. The rapidly rising demand for titanium components demands more efficient manufacturing processes. Material property of Ti-6Al-4V plays an important role in process design and optimization especially for transient large deformations processes such as forming and machining. However, the dynamic mechanical behavior is poorly understood and accurate predictive models have yet to be developed. To obtain meaningful results which reflect the physical mechanisms of large deformation processes, it is essential to study the dynamic mechanical behavior of Ti-6Al-4V. The Johnson-Cook (JC) model has shown to be effective for modeling strain-hardening behavior of metals and it is numerically robust and can easily be used in finite element simulation models. However, the determination of JC model parameters is determined mostly based on split Hopkinson bar pressure (SHPB) test at isothermal conditions, which is very different from those of transient large deformations characterized by quick and high temperature changes. This study focuses on the dynamic mechanical behavior of titanium in transient manufacturing processes. The mechanical behavior of Ti-6Al-4V at large strains and strain rates beyond the isothermal conditions has been studied using the JC model coupled with the adiabatic condition. Heat fraction coefficient and temperature parameter have great effect on Flow stress-strain relationship. A significant drop of the flow stress occurs at large deformations with high strain rates. The flow stress sensitivity to JC strength model parameters was also investigated. The effect of pressure-stress ratio on material failure strain has shown the material may exhibit super plasticity before failure at hydro compression mode.

Impact of fiber structure on edge-wicking of highly-sized paperboard

TAPPI Journal ◽  
2018 ◽  
Vol 17 (08) ◽  
pp. 437-443
Author(s):  
Lebo Xu ◽  
Jeremy Meyers ◽  
Peter Hart
Keyword(s):  
Fiber Surface ◽  
Manufacturing Processes ◽  
Paper Machine ◽  
Liquid Penetration ◽  
Fiber Structure ◽  
Cut Edge ◽  
Local Fiber

Coffee edge-wicking testing was conducted on two groups of highly-sized paperboard manufactured at two mills with similar manufacturing processes, but with vastly different local fiber sources. Although the Hercules size test (HST) indicated similar internal size levels between the two types of board, the edge-wicking behavior was noticeably different. Analysis of fiber structure revealed that the board with more edge-wicking had fibers with thicker fiber walls, which kept the fiber lumen more open after pressing and drying on a paper machine. It was demonstrated that liquid penetration through voids between fibers in highly-sized paperboard was limited, because the fiber surface was well protected by the presence of sufficient sizing agent. Nevertheless, freshly exposed fiber walls and lumens at the cut edge of the sheet were not protected by sizing material, which facilitated edge-wicking. The correlation between fiber structure and edge-wicking behavior was highlighted in this work to inspire development of novel sizing strategies that protect the freshly cut edge of the sheet from edge-wicking.

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