A Proposed Methodology for ECV Fitness-for-Service Evaluation

2021 ◽  
Author(s):  
Thomas A. Duffey ◽  
Joshem C. Gibson
Keyword(s):  
Finite Element ◽  
Numerical Modeling ◽  
Fatigue Fracture ◽  
Brittle Failure ◽  
Ductile Failure ◽  
Service Evaluation ◽  
Spherical Vessel ◽  
Finite Element Calculations ◽  
Post Test ◽  
Thickness Measurements

Abstract A methodology of fitness-for-service evaluation (FFSE) for explosive containment vessels (ECVs) is introduced that utilizes change-in-thickness measurements pre- and post-test to determine the propensity of the structure to ratchet or to shake down. The method focuses on ductile failure and complements previously developed brittle failure methodologies associated with fatigue-fracture of flaws introduced during manufacture or subsequent service. The methodology is illustrated using measured thickness changes on a spherical vessel and is intended to eliminate or diminish the need for detailed, challenging finite element calculations of ratcheting and shakedown. An example is presented, based upon measured thickness changes in an explosively loaded containment vessel. Current limitations of the procedure are discussed. Applicable consensus code requirements and issues with the numerical modeling of ratcheting are briefly presented.

Upon Impact Numerical Modeling of Foam Materials

2017 ◽  
Vol 54 (2) ◽  
pp. 195-202
Author(s):  
Vasile Nastasescu ◽  
Silvia Marzavan
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Numerical Analysis ◽  
Numerical Methods ◽  
Boundary Conditions ◽  
General Character ◽  
Foam Material ◽  
Various Boundary Conditions ◽  
Specific Behaviour

The paper presents some theoretical and practical issues, particularly useful to users of numerical methods, especially finite element method for the behaviour modelling of the foam materials. Given the characteristics of specific behaviour of the foam materials, the requirement which has to be taken into consideration is the compression, inclusive impact with bodies more rigid then a foam material, when this is used alone or in combination with other materials in the form of composite laminated with various boundary conditions. The results and conclusions presented in this paper are the results of our investigations in the field and relates to the use of LS-Dyna program, but many observations, findings and conclusions, have a general character, valid for use of any numerical analysis by FEM programs.

scholarly journals Special Issue “Applications of Finite Element Modeling for Mechanical and Mechatronic Systems”

2021 ◽  
Vol 11 (11) ◽  
pp. 5170
Author(s):  
Marek Krawczuk ◽  
Magdalena Palacz
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Modeling ◽  
Engineering Practice ◽  
The Finite Element Method ◽  
Special Issue ◽  
Mechatronic Systems ◽  
Modeling And Analysis ◽  
Modern Engineering ◽  
Concise Description

Modern engineering practice requires advanced numerical modeling because, among other things, it reduces the costs associated with prototyping or predicting the occurrence of potentially dangerous situations during operation in certain defined conditions. Different methods have so far been used to implement the real structure into the numerical version. The most popular have been variations of the finite element method (FEM). The aim of this Special Issue has been to familiarize the reader with the latest applications of the FEM for the modeling and analysis of diverse mechanical problems. Authors are encouraged to provide a concise description of the specific application or a potential application of the Special Issue.

Investigated Effect of Points Charge of the Receptors on the Conduction of Semiconductor Nanowire

2015 ◽  
Vol 1109 ◽  
pp. 167-170
Author(s):  
M. Wesam Al-Mufti ◽  
U. Hashim ◽  
Mijanur Rahman ◽  
Tijjani Adam ◽  
A.H. Azman ◽  
...  
Keyword(s):  
Finite Element ◽  
Oxide Layer ◽  
Point Charge ◽  
Potential Distribution ◽  
Silicon Nanowire ◽  
Comsol Multiphysics ◽  
Functional Layer ◽  
Semiconductor Nanowire ◽  
Finite Element Calculations

The paper reported a study on an effect of the point charge of the bio-interface of a nanowire field biosensor on the conductance of the nanowire, through finite element calculations using COMSOL Multiphysics. A model with 5 layers starting with silicon nanowire of radius 10nm surrounded by a 2-nm oxide layer, and the oxide layer were surrounded by a 5 nm thick functional layer and 2 points charge were considered for this study and last layer is for electrolyte. The results shows that is different voltages with points change is that effected on the conductance of nanowire that is clear from different of potential distribution of point charge.

Exact analysis of the bending of wide beams by a modified elastica approach

2011 ◽  
Vol 225 (11) ◽  
pp. 2759-2764 ◽  
Author(s):  
L F Campanile ◽  
R Jähne ◽  
A Hasse
Keyword(s):  
Finite Element ◽  
Substantial Reduction ◽  
Short Review ◽  
Computational Effort ◽  
Two Dimensional ◽  
Finite Element Calculations ◽  
Dimensional Finite Element ◽  
Wide Beams ◽  
Insight Into ◽  
Selection Of

Classical beam models do not account for partial restraint of anticlastic bending and are therefore inherently inaccurate. This article proposes a modification of the exact Bernoulli–Euler equation which allows for an exact prediction of the beam's deflection without the need of two-dimensional finite element calculations. This approach offers a substantial reduction in the computational effort, especially when coupled with a fast-solving schema like the circle-arc method. Besides the description of the new method and its validation, this article offers an insight into the somewhat disregarded topic of anticlastic bending by a short review of the published theories and a selection of representative numerical results.

Incompressibility and mesh sensitivity analysis in finite element simulation of rubbers

2016 ◽  
Vol 7 (1) ◽  
pp. 7-12 ◽  
Author(s):  
D. Huri
Keyword(s):  
Finite Element ◽  
Material Characterization ◽  
Numerical Stability ◽  
Material Parameters ◽  
Linear Finite Element ◽  
Element Simulation ◽  
Finite Element Calculations ◽  
Mesh Density ◽  
Rubber Component

Non-linear finite element calculations are indispensable when important information of the material response under load of a rubber component is desired. Although the material characterization of a rubber component is a demanding engineering task, the changing contact range between the parts and the incompressibility behaviour of the rubber further increase the complexity of the investigations. In this paper the effects of the choice of the numerical material parameters (e.g. bulk modulus) are examined with regard to numerical stability, mesh density and calculation accuracy. As an example, a rubber spring is chosen where contact problem is also handled.

Sign in / Sign up

Export Citation Format

Share Document