EFFECT OF BOUNDARY CONDITIONS ON PROCESS- INDUCED STRESSES IN A PLAIN WEAVE UNIT CELL

2021 ◽  
Author(s):  
K. BUKENYA ◽  
M. N. OLAYA ◽  
E. J. PINEDA ◽  
M. MAIARU
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Process Modeling ◽  
Complex Geometry ◽  
Polymer Matrix Composites ◽  
Unit Cell ◽  
Modeling Framework ◽  
Element Analysis ◽  
Finite Element Software ◽  
Aerospace Applications

Woven polymer matrix composites (PMCs) are leveraged in aerospace applications for their desirable specific properties, yet they are vulnerable to high residual stresses during manufacturing and their complex geometry makes experimental results difficult to observe. Process modeling is needed to characterize the effects of the curing and predict end stress states. Finite element software can be used to model woven architectures, however accurate representation of processing conditions remains a challenge when it comes to selecting boundary conditions. The effect of BCs on process-induced stress within woven PMCs is studied. The commercial Finite Element Analysis (FEA) software Abaqus is coupled with user-written subroutines in a process modeling framework. A two-dimensionally (2D) woven PMC repeating unit cell (RUC) is modeled with TexGen and Abaqus. Virtual curing is imposed on the bulk matrix. The BC study is conducted with Free, Periodic, Flat, and Flat-Free configurations. Results show that the end stress state is sensitive to the boundary condition assumptions. Flat BC results show great agreement with Periodic BCs. Residual stress results from process modeling are then compared with a linear-elastic thermal cooldown analysis in Abaqus. Cooldown results indicate an overestimation in matrix stresses compared with process modeling.

Development of Hybrid Semi-Analytical and Finite Element Analysis to Calculate Sound Radiation from Vibrating Structure

2013 ◽  
Vol 845 ◽  
pp. 71-75 ◽  
Author(s):  
Azma Putra ◽  
Nurain Shyafina ◽  
Noryani Muhammad ◽  
Hairul Bakri ◽  
Noor Fariza Saari
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Boundary Conditions ◽  
Rectangular Plate ◽  
Analytical Model ◽  
Complex Geometry ◽  
Sound Radiation ◽  
Vibration Velocity ◽  
Rectangular Plates ◽  
Element Analysis

Simple analytical model of plate dynamics usually applies for rectangular plate with simply supported edges. Analytical model of sound radiation from rectangular plate is also convenient, but not for other geometries and other boundary conditions. This paper presents a hybrid mathematical model which combines a semi-analytical model with the Finite Element Analysis (FEA) method to determine sound radiation from a vibrating structure. The latter is employed to calculate the vibration velocity of a structure with a rather complex geometry. The results are then used as the input in the semi-analytical model to calculate the radiated sound pressure through the Rayleigh integral. Results from the proposed model are presented here for the radiation efficiency of rectangular plates with different boundary conditions.

scholarly journals Shape Sensing of a Complex Aeronautical Structure with Inverse Finite Element Method

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1388
Author(s):  
Daniele Oboe ◽  
Luca Colombo ◽  
Claudio Sbarufatti ◽  
Marco Giglio
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Boundary Conditions ◽  
Strain Field ◽  
Element Analysis ◽  
Inverse Finite Element Method ◽  
Shape Sensing ◽  
Definition Of ◽  
High Level ◽  
Element Method

The inverse Finite Element Method (iFEM) is receiving more attention for shape sensing due to its independence from the material properties and the external load. However, a proper definition of the model geometry with its boundary conditions is required, together with the acquisition of the structure’s strain field with optimized sensor networks. The iFEM model definition is not trivial in the case of complex structures, in particular, if sensors are not applied on the whole structure allowing just a partial definition of the input strain field. To overcome this issue, this research proposes a simplified iFEM model in which the geometrical complexity is reduced and boundary conditions are tuned with the superimposition of the effects to behave as the real structure. The procedure is assessed for a complex aeronautical structure, where the reference displacement field is first computed in a numerical framework with input strains coming from a direct finite element analysis, confirming the effectiveness of the iFEM based on a simplified geometry. Finally, the model is fed with experimentally acquired strain measurements and the performance of the method is assessed in presence of a high level of uncertainty.

Research on Mesh Optimization of the Finite Element Calculation about Three-Dimensional Foundation Pit

2012 ◽  
Vol 487 ◽  
pp. 855-859
Author(s):  
Shi Lun Feng ◽  
Yu Ming Zhou ◽  
Pu Lin Li ◽  
Jun Li ◽  
Zhi Yong Li ◽  
...  
Keyword(s):  
Finite Element ◽  
Complex Geometry ◽  
Three Dimensional ◽  
Mesh Optimization ◽  
Design Calculation ◽  
Foundation Pit ◽  
3D Design ◽  
Finite Element Software ◽  
Core Language ◽  
Grid Division

Abaqus finite element software can implement three-dimensional excavation design calculation, so authors used Python of Abaqus core language made the 3D design of foundation pit supporting program come ture and also did intensive study of mesh optimization during the process. Authors also did intensive comparison and analysis about grid division of the complex geometry foundation pit, through a regularization partion about a variety of special-shaped pit, we made the automatic division about the structural grid of all kinds of shapes foundation pit successful. On this basis, we achieved better calculation effects of the model. The article will introduce problems about optimization of grid in procedure.

scholarly journals Driving forces on dislocations: finite element analysis in the context of the non-singular dislocation theory

2021 ◽  
Author(s):  
Xiandong Zhou ◽  
Christoph Reimuth ◽  
Peter Stein ◽  
Bai-Xiang Xu
Keyword(s):  
Finite Element ◽  
Dislocation Loop ◽  
Driving Force ◽  
Complex Geometry ◽  
Driving Forces ◽  
Singular Solutions ◽  
Dislocation Model ◽  
Configurational Force ◽  
Element Analysis ◽  
Dislocation Configuration

AbstractThis work presents a regularized eigenstrain formulation around the slip plane of dislocations and the resultant non-singular solutions for various dislocation configurations. Moreover, we derive the generalized Eshelby stress tensor of the configurational force theory in the context of the proposed dislocation model. Based on the non-singular finite element solutions and the generalized configurational force formulation, we calculate the driving force on dislocations of various configurations, including single edge/screw dislocation, dislocation loop, interaction between a vacancy dislocation loop and an edge dislocation, as well as a dislocation cluster. The non-singular solutions and the driving force results are well benchmarked for different cases. The proposed formulation and the numerical scheme can be applied to any general dislocation configuration with complex geometry and loading conditions.

Rayleigh-Ritz Analysis of Vibrating Plates Based on a Class of Eigenfunctions

2009 ◽  
Author(s):  
Giuseppe Catania ◽  
Silvio Sorrentino
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Boundary Conditions ◽  
Linear Combination ◽  
Equation Of Motion ◽  
Extensive Literature ◽  
Shape Functions ◽  
Element Analysis ◽  
Vibrating Plates ◽  
General Basis

In the Rayleigh-Ritz condensation method the solution of the equation of motion is approximated by a linear combination of shape-functions selected among appropriate sets. Extensive literature dealing with the choice of appropriate basis of shape functions exists, the selection depending on the particular boundary conditions of the structure considered. This paper is aimed at investigating the possibility of adopting a set of eigenfunctions evaluated from a simple stucture as a general basis for the analysis of arbitrary-shaped plates. The results are compared to those available in the literature and using standard finite element analysis.

A Coupled SBFEM-FEM Approach for Evaluating Stress Intensity Factors

2013 ◽  
Vol 353-356 ◽  
pp. 3369-3377 ◽  
Author(s):  
Ming Guang Shi ◽  
Chong Ming Song ◽  
Hong Zhong ◽  
Yan Jie Xu ◽  
Chu Han Zhang
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Stress Intensity ◽  
Stress Intensity Factors ◽  
Complex Geometry ◽  
Stress Singularity ◽  
Intensity Factors ◽  
Finite Element Software ◽  
Scaled Boundary Finite Element ◽  
Element Method

A coupled method between the Scaled Boundary Finite Element Method (SBFEM) and Finite Element Method (FEM) for evaluating the Stress Intensity Factors (SIFs) is presented and achieved on the platform of the commercial finite element software ABAQUS by using Python as the programming language. Automatic transformation of the finite elements around a singular point to a scaled boundary finite element subdomain is realized. This method combines the high accuracy of the SBFEM in computing the SIFs with the ability to handle material nonlinearity as well as powerful mesh generation and post processing ability of commercial FEM software. The validity and accuracy of the method is verified by analysis of several benchmark problems. The coupled algorithm shows a good converging performance, and with minimum additional treatment can be able to handle more problems that cannot be solved by either SBFEM or FEM itself. For fracture problems, it proposes an efficient way to represent stress singularity for problems with complex geometry, loading condition or certain nonlinearity.

Finite Element Analysis of Main Stand of Ф140 Pipe Rolling Mill and Split Casting

2013 ◽  
Vol 690-693 ◽  
pp. 2327-2330
Author(s):  
Ming Bo Han ◽  
Li Fei Sun
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Rolling Mill ◽  
Analysis Model ◽  
Element Analysis ◽  
Pipe Rolling ◽  
Full Load ◽  
Finite Element Software ◽  
Theoretical Position ◽  
Technical Requirements

By using finite element software, the paper establishes the main stand analysis model of the Ф140 pipe rolling mill and provides the model analysis of main stand in cases of full load. Verify the design of main stand fully comply with the technical requirements .In this paper, it provides the theoretical position of split casting and welding method using electric slag welding.

Finite Element Analysis of Uniaxial Compression of Glazed Hollow Bead of Recycled Concrete Short Columns

2014 ◽  
Vol 898 ◽  
pp. 399-402
Author(s):  
Heng Sun ◽  
Bai Shou Li
Keyword(s):  
Finite Element ◽  
Uniaxial Compression ◽  
Recycled Concrete ◽  
Intensity Level ◽  
Concrete Wall ◽  
Element Analysis ◽  
Ordinary Concrete ◽  
Ansys Simulation ◽  
Finite Element Software ◽  
Short Columns

For traditional ordinary concrete wall column prone to thermal bridges, posted outside the insulation board short life than the life of the building，in the glazed hollow bead of recycled concrete foundation with good thermal conductivity test and compressive strength of the proposed ,use glazed hollow bead of recycled concrete exterior wall column instead of the traditional ordinary concrete wall column ,and using the finite element software ANSYS simulation analysis the uniaxial compression of glazed hollow bead of recycled concrete short columns and ordinary concrete short columns. Comparative analysis showed the same intensity level glazed hollow bead of recycled concrete ultimate compressive bearing capacity of an analog value the same as ordinary concrete short columns. To validate the ANSYS simulation of concrete short columns under uniaxial compression condition .

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