Analysis of Stiffened Plates Using the Boundary Element and Finite Element Hybrid Method

1991 ◽  
Author(s):  
Hui-Ru Shih ◽  
Roger C. Duffield
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Boundary Element ◽  
Hybrid Method ◽  
Plate Boundary ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Compatibility Conditions ◽  
Integral Equation Formulation ◽  
Bending Problems

Abstract The boundary element and finite element hybrid method, based on a combination of unstiffened plate boundary element method and stiffener finite elements, is employed for static analysis of concentrically stiffened plates subjected to transverse loading. The integral equation formulation and its boundary element solution procedures for bending of a unstiffened plate are briefly reviewed. The algorithm which permits coupling of the unstiffened plate boundary elements with the beam (stiffener) finite elements is presented. The numerical implementations of the equilibrium and compatibility conditions along the interface between the plate and its stiffener are given in detail. Numerical examples illustrate the accuracy as well as the capability of the proposed method to determine the solution of stiffened plate bending problems.

A Comparative Numerical Study on the Bending Response of Aluminium Stiffened Plates With Fixed/Floating Frames

2008 ◽  
Author(s):  
Mohammad Reza Khedmati ◽  
Mehran Rastani
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Numerical Study ◽  
Point Of View ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Finite Element Analyses ◽  
Bending Response ◽  
Structural Arrangements

In this paper, different structural arrangements of the transverse frames in an orthogonally stiffened plate are investigated from the bending response point of view. The transverse frames are assumed to be either fixed or floating. Other alternate placements of the transverse frames are also included in the comparative calculations. Stress and deflection contours are obtained via finite element analyses. Finally, some recommendations are outlined comparing the results of maximum stress and deflection with the allowable limits.

Simulation of Axisymmetric Forming Processes, With Friction, Coupling Finite Elements and Boundary Elements

2006 ◽  
Author(s):  
Dominique Bigot ◽  
Hocine Kebir ◽  
Jean-Marc Roelandt
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Element Method ◽  
Finite Elements ◽  
Boundary Element ◽  
Symmetric Part ◽  
Forming Process ◽  
Optimal Shapes ◽  
Numerical Software ◽  
Element Method

Nowadays, the simulation of forming processes is rather well integrated in the industrial numerical codes. However, to take into account the possible modifications of the tool during cycle of working, we develop dedicated numerical software. This one more particularly will allow the identification of the fatigue criteria of the tool. With the view to conceiving the optimal shapes of tool allowing increasing their lifespan while ensuring a quality required of the part thus manufactured. This latter uses coupling with friction finite element method — for modelling the axi-symmetric part — and boundary element method — for modelling the tool. For the validation, we modeled forming process.

Nonlinear Elastoplastic Behaviour of Intermittently Welded Stiffened Plates Under Inplane Compression

2006 ◽  
Author(s):  
Mohammad Reza Khedmati ◽  
Mehran Rastani
Keyword(s):  
Finite Element ◽  
Compressive Load ◽  
Steel Plates ◽  
Stiffened Plates ◽  
Finite Element Code ◽  
Stiffened Plate ◽  
Plate Models ◽  
Different Types ◽  
Stiffened Steel ◽  
Continuous Chain

The objective of this study is to investigate the sensitivity of the ultimate strength and failure mechanism of stiffened plates constructed by different welding methods in common. A series of detailed numerical analyses of longitudinally stiffened steel plates subjected to inplane compressive load are performed using ADINA commercial finite element code. Complete equilibrium paths are traced up to collapse for nonlinear elastoplastic response of stiffened plates. Stiffened plates analysed are imperfect and their aspect ratio, plate slenderness and column slenderness are changed in a systematic manner. Different types of stiffener are chosen for stiffened plate models. Three different stiffener-to-plate welding procedures are considered: continuous, chain intermittent and staggered intermittent fillet welding.

scholarly journals Comparison of Numerical Simulation Techniques of Ballistic Ceramics under Projectile Impact Conditions

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 18
Author(s):  
Pawel Zochowski ◽  
Marcin Bajkowski ◽  
Roman Grygoruk ◽  
Mariusz Magier ◽  
Wojciech Burian ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Elements ◽  
Hybrid Method ◽  
Experimental Tests ◽  
Failure Criteria ◽  
Ceramic Tiles ◽  
Projectile Impact ◽  
Backing Plate ◽  
Composite Armor ◽  
Steel Composite

This article presents an analysis of the effectiveness of available numerical techniques in mapping the characteristic behavior of ballistic ceramics under projectile impact conditions. As part of the work, the ballistic tests were performed on the layered ceramic/steel composite armor and tested with the 7.62 × 39 mm, armor-piercing incendiary (API) BZ projectile. The experimental tests were then mapped using computer simulations. In numerical analyses, four different techniques were used to describe cubic ceramic tiles Al2O3 placed on the ARMOX 500T steel backing plate, i.e.,: the Finite Element Method without Erosion (FEM), Finite Element with erosion (FEM + Erosion), Smoothed Particles Hydrodynamics (SPH) and a hybrid method that converts finite elements to SPH particles after exceeding the defined failure criteria (FEM to SPH conversion). The effectiveness of the individual methods was compared in terms of quality (mapping of characteristic phenomena occurring during the penetration process), quantity (bulge height of the backing plate) and time needed to complete the calculations. On the basis of the results of the experiments and numerical simulations, it was noticed that the most accurate reproduction of the phenomenon of ballistic impact of AP projectiles on ceramic/steel composite armor can be obtained by using a hybrid method, incorporating the conversion of finite elements into SPH particles. This method should be used in cases where accuracy of the results is more important than the time required to complete the calculations. In other situations where the purpose of the calculation is not to determine, for example, the exact value of penetration depth but only to observe a certain trend, the FEM method with defined erosion criteria (variant 2), which is more than 10 times faster, can be successfully used.

Ultimate Strength Characteristics of a Ship's Deck Stiffened Plate Structure in the Presence of Camber Parabolic Curvature

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Mohammad Reza Khedmati ◽  
Pedram Edalat
Keyword(s):  
Finite Element ◽  
Ultimate Strength ◽  
Parametric Model ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
Finite Element Program ◽  
Main Target ◽  
Element Program ◽  
Plane Compression ◽  
And Behavior

The main target of this research is to identify the effects of camber parabolic curvature on the ultimate strength and behavior of stiffened plates under in-plane compression. A parametric model for the study of the problem is created. The model includes different parameters related to plate, stiffeners, and also parabolic camber curvature. Three distinct sensitivity cases are assumed. In each sensitivity case, many different models are analyzed and their ultimate strengths are obtained using an in-house finite element program. Ultimate strength and behavior of the models with different ratios of parabolic curvature are compared to each other and interpreted.

scholarly journals Effects of Equipment Loading on the Vibrations of Edge-Stiffened Plates and Associated Modeling Issues

2002 ◽  
Author(s):  
Robert L. Campbell ◽  
Stephen A. Hambric
Keyword(s):  
Finite Element ◽  
Structural Response ◽  
Element Model ◽  
Mode Shapes ◽  
Stiffened Plates ◽  
Fe Model ◽  
Complex Structures ◽  
Mass Loading ◽  
Stiffened Plate ◽  
Radiated Noise

Predicting structural radiated noise is a process that involves several steps, often including the development of a finite element (FE) model to provide structural response predictions. Limitations of these FE models often govern the success of overall noise predictions. The purpose of the present investigation is to identify the effects of real world attachments on edge-stiffened plates and identify advanced modeling methods to facilitate vibroacoustic analyses of such complex structures. A combination of experimental and numerical methods is used in the evaluation. The results show the effects of adding attachments to the edge-stiffened plate in terms of mode shape mass loading, creation of new mode shapes, modifications to original mode shapes, and variations in damping levels. A finite element model of the edge-stiffened plate with simplified attachments has been developed and is used in conjunction with experimental data to aid in the developments. The investigation presented here represents a necessary first step toward implementing an advanced modeling technique.

scholarly journals ANALYSIS THROUGH CONSTRUCTAL DESIGN OF THE INFLUENCE OF SPACING BETWEEN STIFFENERS IN THE DEFLECTION OF PLATES

2020 ◽  
Vol 5 (5) ◽  
Author(s):  
Milton Cesar Bastos Portela Junior ◽  
Vinícius Torres Pinto ◽  
Luiz Alberto Oliveira Rocha ◽  
Elizaldo Domingues Dos Santos ◽  
Liércio André Isoldi
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Design Method ◽  
Stiffened Plates ◽  
Stiffened Plate ◽  
The Finite Element Method ◽  
Volumetric Fraction ◽  
Constructal Design ◽  
Fixed Volume ◽  
Reference Plate

Using the Finite Element Method (FEM), stiffened plates arrangements defined by the application of the Constructal Design Method (CDM) were analyzed. So that, through an Exhaustive Search (ES), different spacing between the stiffeners were tested regarding the central and maximum deflections. Starting from a non-stiffened plate with a fixed volume, a portion of its material was completely removed from its thickness and transformed into stiffeners considering the volumetric fraction 𝜙 = 0.5. It were established 4 arrangements: P(2,2), P(2,3), P(3,2) and P(3,3), varying for each one, the spacing between the stiffeners, as well as the parameter hs/ts (ratio between height and thickness of stiffeners). The results showed that stiffeners equally spaced in the longitudinal and transverse directions with higher ratios hs/ts are more effective, being able to reduce the central and maximum deflections by more than 95% compared to the non-stiffened reference plate.

Sign in / Sign up

Export Citation Format

Share Document