Combined paraxial-consistent boundary conditions finite element model for simulating wave propagation in elastic half-space media

2015 ◽  
Vol 70 ◽  
pp. 80-92 ◽  
Author(s):  
N. Hamdan ◽  
O. Laghrouche ◽  
P.K. Woodward ◽  
A. El-Kacimi
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Half Space ◽  
Element Model ◽  
Elastic Half Space

Towards Truly Multiscale Simulation of Fatigue Processes in Metallic Structures

2009 ◽  
Author(s):  
John M. Emery ◽  
Jeffrey E. Bozek ◽  
Anthony R. Ingraffea
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Life Prediction ◽  
Element Model ◽  
Multiscale Simulation ◽  
Fatigue Life Prediction ◽  
Length Scale ◽  
Metallic Structures

The fatigue resistance of metallic structures is inherently random due to environmental and boundary conditions, and microstructural geometry, including discontinuities, and material properties. A new methodology for fatigue life prediction is under development to account for these sources of randomness. One essential aspect of the methodology is the ability to perform truly multiscale simulations: simulations that directly link the boundary conditions on the structural length scale to the damage mechanisms of the microstructural length scale. This presentation compares and contrasts two multiscale methods suitable for fatigue life prediction. The first is a brute force method employing the widely-used multipoint constraint technique which couples a finite element model of the microstructure within the finite element model of the structural component. The second is a more subtle, modified multi-grid method which alternates analyses between the two finite element models while representing the evolving microstructural damage. Examples and comparisons are made for several geometries and preliminary validation is achieved with comparison to experimental tests conducted by the Northrop Grumman Corporation on a wing-panel structural geometry.

Finite Element Solution for Wave Propagation in Layered Fluids

1997 ◽  
Vol 05 (04) ◽  
pp. 383-402
Author(s):  
Tony W. H. Sheu ◽  
C. C. Fang
Keyword(s):  
Finite Element ◽  
Wave Propagation ◽  
Finite Element Model ◽  
Element Model ◽  
Analytic Solutions ◽  
Analysis Tool ◽  
Galerkin Finite Element ◽  
Flux Corrected Transport ◽  
Characteristic Finite Element ◽  
Medium Change

A hyperbolic equation is considered for the propagation of pressure disturbance waves in layered fluids having different fluid properties. For acoustic problems of this sort, the characteristic finite element model alone does not suffice to ensure prediction of the monotonic wave profile across fluids having different properties. A flux corrected transport solution algorithm is intended for incorporation into the underlying Taylor–Galerkin finite element framework. The advantage of this finite element approach, in addition to permitting oscillation-free solutions, is that it avoids the necessity of dealing with medium discontinuity. As an analysis tool, the proposed monotonic finite element model has been intensively verified through problems which are amenable to analytic solutions. In modeling wave propagation in layered fluids, we have investigated the influence of the degree of medium change on the finite element solutions. Also, different finite element solutions are considered to show the superiority of using the flux corrected transport Taylor–Galerkin finite element model.

Sign in / Sign up

Export Citation Format

Share Document