Dynamic Wrinkling of Viscoelastic Membranes

1993 ◽  
Vol 60 (3) ◽  
pp. 575-582 ◽  
Author(s):  
C. H. Jenkins ◽  
J. W. Leonard
Keyword(s):  
Finite Element ◽  
Constitutive Equation ◽  
Strain Energy ◽  
Temporal Integration ◽  
Nonlinear Finite Element ◽  
Analysis Method ◽  
Finite Difference Equation ◽  
Membrane Structures ◽  
Newton Raphson ◽  
Raphson Method

Problems associated with viscoelastic membrane structures have been documented, e.g., dynamic wrinkling and its effects on fatigue analysis and on snap loading. In the proposed analysis method, the constitutive equation is approximated by a finite difference equation and embedded within a nonlinear finite element spatial discretization. Implicit temporal integration and a modified Newton-Raphson method are used within a time increment. The stress-strain hereditary relation is formally derived from thermodynamic considerations. Use of modified strain-energy and dissipation functions facilitates the description of wrinkling during the analysis. Applications are demonstrated on an inflated cylindrical cantilever and on a submerged cylindrical membrane excited by waves.

Influence of Transverse Cracks on Ultimate Strength of a Steel Plate Under Compression

2011 ◽  
Author(s):  
Abbas Bayatfar ◽  
Jerome Matagne ◽  
Philippe Rigo
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Steel Plate ◽  
Transverse Cracks ◽  
Longitudinal Compression ◽  
Initial Imperfections ◽  
Crack Location ◽  
Linear Finite Element ◽  
Newton Raphson ◽  
Raphson Method

This study has been carried out on ultimate compressive strength of a cracked steel plate component, considering the effects of initial imperfections (transverse and longitudinal residual stresses and initial deflection, as well). The main objective of this paper is to numerically investigate the influence of crack location and crack length on ultimate strength of a steel plate under monotonic longitudinal compression. This investigation is performed through non-linear finite element (FE) analysis using ANSYS commercial finite element code in which is employed Newton-Raphson method. The FE results indicate that the length of transverse crack and especially its location can significantly affect the magnitude of ultimate strength where the steel plate is subjected to longitudinal compressive action.

Reliability Analysis of Radial Tire

2011 ◽  
Vol 120 ◽  
pp. 436-439
Author(s):  
Chang Shun Zhu ◽  
Guo Lin Wang ◽  
Ping Ping Li ◽  
Ru Yu Ma
Keyword(s):  
Finite Element ◽  
Strain Energy Density ◽  
Strain Energy ◽  
Failure Modes ◽  
Structural Parameters ◽  
Random Variable ◽  
Analysis Method ◽  
Rubber Material ◽  
Material Parameters ◽  
Sensitivity Analysis Method

Aimed at the radial tire's randomness in the structural parameters and material properties, etc., took the strain energy density of the tire carcass ply turn-up end as the objective function on the basis of analysis of the tire’s main failure modes, chose the tire carcass ply turn-up height and the rubber material parameters as random variable by using the Finite Element sensitivity analysis method(DSA), On this basis, adopted Monte-Carlo stochastic finite element method to calculate the reliability of the fatigue life of tire.

Improved Rotative Mid-Point Mensuration and Newton-Raphson Method in 2-D Flat Rolling Simulation

2011 ◽  
Vol 328-330 ◽  
pp. 1436-1439
Author(s):  
Shu Ni Song ◽  
Jing Yi Liu
Keyword(s):  
Finite Element ◽  
Simultaneous Equations ◽  
Rigid Plastic ◽  
Cpu Time ◽  
Numerical Tests ◽  
Element Simulation ◽  
Flat Rolling ◽  
Newton Raphson ◽  
Time Required ◽  
Raphson Method

Newton-Raphson (N-R) method has been employed to solve the system of simultaneous equations arising in Rigid-Plastic finite element simulation. The combination of the improved rotative mid-point mensuration and the N-R method, named the M-P method is designated to solve the equations of velocity increment in Rigid-Plastic FEM. The CPU times required for calculation by the M-P method and the N-R method are compared and it is found that the CPU time required for calculation of the N-R method is more than the M-P method. The calculated rolling forces by the M-P method and the N-R method are compared and it is found that the former correlates better with the measured value. Numerical tests and application show that the M-P method is feasible and steady.

Research on Thermal Mechanical Properties of Rubber Like Materials Based on Numerical Simulation

2011 ◽  
Vol 704-705 ◽  
pp. 811-816
Author(s):  
Jian Bin Sang ◽  
Wen Ying Yu ◽  
Bo Liu ◽  
Xiao Lei Li ◽  
Tie Feng Liu
Keyword(s):  
Finite Element ◽  
Energy Function ◽  
Strain Energy ◽  
Strain Energy Function ◽  
Mechanical Analysis ◽  
Nonlinear Finite Element ◽  
Uniaxial Tensile ◽  
Uniaxial Tensile Test ◽  
Rubber Seal ◽  
Thermal Mechanical Analysis

This paper start with a discussion on various types of strain energy functions of rubber like materials. Theoretical analysis based on the strain energy function given in by Y.C.Gao in 1997 is proposed. The material parameters of strain energy function were curve-fitted from the uniaxial tensile test. The selected constitutive relation of rubber like materials was implemented into a finite element code MSC.Marc as a user material subroutine to analyze the thermal and mechanical behavior of rubber seal under the plane strain conditions. Contact force and distribution of the contact stress between lip seal and shaft are analyzed and coupled thermal mechanical analysis of rubber seal was proposed. The contact pressure distribution is readily obtainable from the nonlinear finite element analysis and the coupled thermal mechanical analyses results indicate that the thermal stress only have minor influence on the deformed shape of rubber seal, which will be a useful technique for predicting the properties of rubber seal and providing reference for engineering design. Keywords:rubber like materials, nonlinear finite element, contact analysis, thermal mechanical analysis

Finite Element-Based Brownian Dynamics Simulation of Nanofiber Suspensions Using Monte Carlo Method1

2015 ◽  
Vol 3 (4) ◽  
Author(s):  
Dongdong Zhang ◽  
Douglas E. Smith
Keyword(s):  
Finite Element ◽  
Monte Carlo ◽  
Brownian Dynamics ◽  
Element Model ◽  
Dynamics Simulation ◽  
Brownian Dynamics Simulation ◽  
Fiber Motion ◽  
Newton Raphson ◽  
Raphson Method ◽  
Surrounding Fluid

This paper presents a computational approach for simulating the motion of nanofibers during fiber-filled composites processing. A finite element-based Brownian dynamics simulation (BDS) is proposed to solve for the motion of nanofibers suspended within a viscous fluid. We employ a Langevin approach to account for both hydrodynamic and Brownian effects. The finite element method (FEM) is used to compute the hydrodynamic force and torque exerted from the surrounding fluid. The Brownian force and torque are regarded as the random thermal disturbing effects which are modeled as a Gaussian process. Our approach seeks solutions using an iterative Newton–Raphson method for a fiber's linear and angular velocities such that the net forces and torques, including both hydrodynamic and Brownian effects, acting on the fiber are zero. In the Newton–Raphson method, the analytical Jacobian matrix is derived from our finite element model. Fiber motion is then computed with a Runge–Kutta method to update fiber position and orientation as a function of time. Instead of remeshing the fluid domain as a fiber migrates, the essential boundary condition is transformed on the boundary of the fluid domain, so the tedious process of updating the stiffness matrix of finite element model is avoided. Since the Brownian disturbance from the surrounding fluid molecules is a stochastic process, Monte Carlo simulation is used to evaluate a large quantity of motions of a single fiber associated with different random Brownian forces and torques. The final fiber motion is obtained by averaging numerous fiber motion paths. Examples of fiber motions with various Péclet numbers are presented in this paper. The proposed computational methodology may be used to gain insight on how to control fiber orientation in micro- and nanopolymer composite suspensions in order to obtain the best engineered products.

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