Improvement on the Analysis of a Finite Element Composites Model

Author(s):  
Atanas A. Atanasov ◽  
Thomas J. Wright ◽  
John P. Parmigiani

Finite element models are increasingly being utilized in composite materials design; thus, an increase in the accuracy of the model analysis and a decrease in computational cost are of paramount importance. This study investigates the effects of a particular add-on, Helius:MCT (Firehole Technologies, Inc.), onto the Abaqus (Dassault Systèmes) software package. Unlike the stand-alone Abaqus software, Helius:MCT embodies a solver, which analyzes the composite structure by separating the fiber and matrix into constituent parts. Treating the fiber and matrix as separate, yet linked entities, allows for a more accurate depiction of the formations of stress and strain within the composite. Furthermore, Helius:MCT utilizes a method called Intelligent Discrete Softening (IDS), a feature not present within Abaqus, to increase solver robustness and convergence probability. An Abaqus finite element (FE) model of a notched, carbon-fiber panel loaded in bending was used in this study. Six different laminate combinations were tested with six variations of the Abaqus model. Three of the variations used Helius:MCT with Abaqus and three the stand-alone Abaqus package. The combinations were composed of either 20 or 40 plies with 10, 30, or 50 percent all zero ply orientations. All the FE analysis results were compared to experimental values for a plate of the exact configuration as that of the model. The most accurate results were obtained using Helius:MCT. The configuration with the greatest accuracy utilizes Helius:MCT and deviates an average of 1.7 percent from experimental values for maximum flexural strength. A single run takes an average of 7 hours to complete. Conversely, the most accurate configuration obtained without the use of Helius:MCT deviates an average of 10 percent from the experimental values and takes over 80 hours to run. Helius: MCT increases the accuracy and decreases the computational costs of the analyses of composite models in Abaqus. The improvements in analyses while using Helius: MCT may allow for a substantial savings in experimental costs and in valuable time.

2021 ◽  
Vol 263 (1) ◽  
pp. 5301-5309
Author(s):  
Luca Alimonti ◽  
Abderrazak Mejdi ◽  
Andrea Parrinello

Statistical Energy Analysis (SEA) often relies on simplified analytical models to compute the parameters required to build the power balance equations of a coupled vibro-acoustic system. However, the vibro-acoustic of modern structural components, such as thick sandwich composites, ribbed panels, isogrids and metamaterials, is often too complex to be amenable to analytical developments without introducing further approximations. To overcome this limitation, a more general numerical approach is considered. It was shown in previous publications that, under the assumption that the structure is made of repetitions of a representative unit cell, a detailed Finite Element (FE) model of the unit cell can be used within a general and accurate numerical SEA framework. In this work, such framework is extended to account for structural-acoustic coupling. Resonant as well as non-resonant acoustic and structural paths are formulated. The effect of any acoustic treatment applied to coupling areas is considered by means of a Generalized Transfer Matrix (TM) approach. Moreover, the formulation employs a definition of pressure loads based on the wavenumber-frequency spectrum, hence allowing for general sources to be fully represented without simplifications. Validations cases are presented to show the effectiveness and generality of the approach.


Designs ◽  
2018 ◽  
Vol 2 (4) ◽  
pp. 43 ◽  
Author(s):  
Bernard B. Munyazikwiye ◽  
Dmitry Vysochinskiy ◽  
Mikhail Khadyko ◽  
Kjell G. Robbersmyr

Estimating the vehicle crashworthiness experimentally is expensive and time-consuming. For these reasons, different modelling approaches are utilised to predict the vehicle behaviour and reduce the need for full-scale crash testing. The earlier numerical methods used for vehicle crashworthiness analysis were based on the use of lumped parameters models (LPM), a combination of masses and nonlinear springs interconnected in various configurations. Nowadays, the explicit nonlinear finite element analysis (FEA) is probably the most widely recognised modelling technique. Although informative, finite element models (FEM) of vehicle crash are expensive both in terms of man-hours put into assembling the model and related computational costs. A simpler analytical tool for preliminary analysis of vehicle crashworthiness could greatly assist the modelling and save time. In this paper, the authors investigate whether a simple piecewise LPM can serve as such a tool. The model is first calibrated at an impact velocity of 56 km/h. After the calibration, the LPM is applied to a range of velocities (40, 48, 64 and 72 km/h) and the crashworthiness parameters such as the acceleration severity index (ASI) and the maximum dynamic crush are calculated. The predictions for crashworthiness parameters from the LPM are then compared with the same predictions from the FEA.


2014 ◽  
Vol 651-653 ◽  
pp. 1197-1200
Author(s):  
Kai Wen Li ◽  
Zhi Yang Li ◽  
Yun Zou

Finite element analysis could be used as a supplementary means to investigate mechanical behavior. ABAQUS software is conducted to analyze steel reinforced concrete (SRC) columns. Firstly, in order to validate the rationality of the analytical model, finite element models of test specimens are established to simulate the test process. By comparing the analytical results with experimental ones, it is found that the results from finite element analysis coincide well with that from test. So ABAQUS software could be used as a supplementary means to simulate SRC column mechanical behavior . Further the ductility and ultimate capacity of SRC columns are studied with the changes of steel bone ratio and the axial compressive ratio.


Author(s):  
Noman Khandoker ◽  
Monir Takla ◽  
Thomas Ting

Simple spot weld connection models are desirable in huge and complicated finite element models of automotive body-in-white structures which generally contains thousands of spot weld joints. Hence, in this paper six different individual spot weld joint finite element models simplified in terms of their geometric and constitutive representations were developed including the one that is currently used in automotive industries. The stiffness characteristics of these developed models were compared with the experimental results obtained following a simple strategy to design the welded joint based on the desired mode of nugget pull out failure. It was found that the current spot weld modeling practice in automotive industry under predict the maximum joint strength nearly by 50% for different loading conditions. The computational costs incurred by the developed models in different loading conditions were also compared. Hence, a suitable model for spot welded joints is established which is very simple to develop but relatively cheap in terms of computational costs.


Author(s):  
Zahra Shahbazi ◽  
Devon Keane ◽  
Domenick Avanzi ◽  
Lance S. Evans

Finite element analysis (FEA) has been one of the successful tools in studying mechanical behavior of biological materials. There are many instances where creating FE models requires extensive time and effort. Such instances include finite element analysis of tree branches with complex geometries and varying mechanical properties. Once a FE model of a tree branch is created, the model is not applicable to another branch, and all the modeling steps must be repeated for each new branch with a different geometry and, in some cases, material. In this paper, we describe a new and novel program “Immediate-TREE” and its associated guided user interface (GUI). This program provides researchers a fast and efficient tool to create finite element analysis of a large variety of tree branches. Immediate-TREE automates the process of creating finite element models with the use of computer-generated Python files. Immediate-TREE uses tree branch data (geometry, mechanical, and material properties) and generates Python files. Files were then run in finite element analysis software (abaqus) to complete the analysis. Immediate-TREE is approximately 240 times faster than creating the same model directly in the FEA software (abaqus). This new process can be used with a large variety of biological applications including analyses of bones, teeth, as well as known biological materials.


2019 ◽  
Vol 9 (21) ◽  
pp. 4495 ◽  
Author(s):  
Mucha

Hybrid simulation is a technique for testing mechanical systems. It applies to structures with elements hard or impossible to model numerically. These elements are tested experimentally by straining them by means of actuators, while the rest of the system is simulated numerically using a finite element method (FEM). Data is interchanged between experiment and simulation. The simulation is performed in real-time in order to accurately recreate the dynamic behavior in the experiment. FEM is very computationally demanding, and for systems with a great number of degrees of freedom (DOFs), real-time simulation with small-time steps (ensuring high accuracy) may require powerful computing hardware or may even be impossible. The author proposed to swap the finite element (FE) model with an artificial neural network (ANN) to significantly lower the computational cost of the real-time algorithm. The presented examples proved that the computational cost could be reduced by at least one number of magnitude while maintaining high accuracy of the simulation; however, obtaining appropriate ANN was not trivial and might require many attempts.


2019 ◽  
Vol 16 (161) ◽  
pp. 20190674 ◽  
Author(s):  
Nuria Melisa Morales-García ◽  
Thomas D. Burgess ◽  
Jennifer J. Hill ◽  
Pamela G. Gill ◽  
Emily J. Rayfield

Finite-element (FE) analysis has been used in palaeobiology to assess the mechanical performance of the jaw. It uses two types of models: tomography-based three-dimensional (3D) models (very accurate, not always accessible) and two-dimensional (2D) models (quick and easy to build, good for broad-scale studies, cannot obtain absolute stress and strain values). Here, we introduce extruded FE models, which provide fairly accurate mechanical performance results, while remaining low-cost, quick and easy to build. These are simplified 3D models built from lateral outlines of a relatively flat jaw and extruded to its average width. There are two types: extruded (flat mediolaterally) and enhanced extruded (accounts for width differences in the ascending ramus). Here, we compare mechanical performance values resulting from four types of FE models (i.e. tomography-based 3D, extruded, enhanced extruded and 2D) in Morganucodon and Kuehneotherium . In terms of absolute values, both types of extruded model perform well in comparison to the tomography-based 3D models, but enhanced extruded models perform better. In terms of overall patterns, all models produce similar results. Extruded FE models constitute a viable alternative to the use of tomography-based 3D models, particularly in relatively flat bones.


Author(s):  
J. Jayapriya ◽  
D Muruganandam ◽  
B. Senthil Kumar

Carbon Nano Tubes (CNTs) have a nanostructure with length-to-diameter ratio greater than 1,000,000 exhibiting unusually high toughness and elastic-moduli. Young’s modulus of a single-walled CNT is estimated through Molecular Structural Mechanics Approach is being simulated as a frame-like-structure where primary bonds between successive atoms forms a beam. Properties for FE model are calculated from energy equivalence between molecular and structural mechanics. By validation, computed results match well with the literature. Finite element models such as armchair and zig-zag are established and Young’s-moduli are effectively predicted.


Author(s):  
Raymond E. Martin ◽  
David M. O’Brien

Abstract Finite element models used in the dynamic analysis of structures benefit from correlation with experimental data at each step in the analytical development. The steps Aircraft Landing Systems has followed in obtaining both modal and operational data for the validation of aircraft wheel, brake, and strut FEA models are discussed in this paper. These steps include the creation of a valid experimental modal model for major components in the structure, correlation of the modal results to tie FE model results, testing of sub-assemblies, and collecting data from dynamometer tests of the system and their correlation to the assembled FE model of the system. Various procedures are described which have been developed and adapted by Aircraft Landing Systems and which enable practical correlation to frequencies as high as 2000 Hz. The application of the procedures are demonstrated with examples from recent testing.


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