A minimisation algorithm with application to optimal design of reinforcements in textiles and garments

2007 ◽  
Vol 19 (3/4) ◽  
pp. 159-166
Author(s):  
Željko Šomodi ◽  
Anica Hursa ◽  
Dubravko Rogale
Keyword(s):  
Finite Element ◽  
Optimal Design ◽  
Objective Function ◽  
Influence Factors ◽  
Element Model ◽  
Geometrical Parameters ◽  
Elastic Model ◽  
Element Analysis ◽  
Elliptic Paraboloid ◽  
Content Type

PurposeThis paper aims to develop an efficient two‐variable minimisation algorithm and to apply it in engineering optimisation of buttonhole reinforcements.Design/methodology/approachAn iterative extreme search is based on quadratic approximation of objective function, locating approximate solution at the minimum of corresponding elliptic paraboloid. Stress analysis is performed using plane stress finite element model. Optimal selection of geometrical parameters of buttonhole‐type reinforcement is done in terms of balance between maximum stress and material consumption.FindingsAdopted minimisation algorithm is assessed in a selected test example and proven to perform well in comparison with methods available in literature. In the selected case two local minima have been found within the predefined optimisation domain, with slight difference in objective function values.Research limitations/implicationsResearch is limited to homogeneous isotropic elastic model and a single representative load case. Objective function is restricted to two influence factors and predefined optimisation domain.Practical implicationsThe method can be useful for engineers/practitioners in the branch of clothing technology as a tool for computational estimate of optimal design of structural reinforcements.Originality/valueThe main quality of the paper is in software fusion of finite element analysis and advanced optimisation algorithm. The proposed theoretical‐numerical model is discussed in terms of applicability in parameter setting on buttonholer in garment production.

Finite Element Analysis of Fixation System Influence on the Thoracolumbar Spine Stability

2016 ◽  
Vol 821 ◽  
pp. 685-692 ◽  
Author(s):  
Klaudia Szkoda ◽  
Celina Pezowicz
Keyword(s):  
Finite Element ◽  
Sagittal Plane ◽  
Thoracolumbar Spine ◽  
Element Model ◽  
Intervertebral Discs ◽  
Vertebral Compression Fractures ◽  
Geometrical Parameters ◽  
Element Analysis ◽  
Transpedicular Fixation ◽  
The Stability

All segments of the spine are characterized by a corresponding curvature in the sagittal plane and different geometrical parameters of vertebrae, which affects the complicated structure of transition between subsequent segments. The aim of the study was to assess changes occurring in the thoracolumbar spine, as a result of application of the transpedicular fixation. The research was conducted on finite element model, which was constructed on the basis of CT images. Five different configurations of the model were analyzed: focusing on vertebral compression fractures and degeneration of intervertebral discs. The analysis showed that the highest displacement occurred for a segment with intervertebral disc degeneration. Transpedicular fixation of injured thoracolumbar spine is given the opportunity to improve the stability and stiffness of the segment under consideration.

Analysis and optimization of the strain concentration factor in countersunk rivet holes via finite element and response surface methods

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohannad Jreissat ◽  
Mohammad A. Gharaibeh
Keyword(s):  
Finite Element ◽  
Response Surface ◽  
Concentration Factor ◽  
Element Model ◽  
Rectangular Plates ◽  
Element Analysis ◽  
Content Type ◽  
Response Surface Methods ◽  
Strain Concentration ◽  
Factor Data

PurposeThe purpose of this paper is to investigate the strain concentration factor in a central countersunk hole riveted in rectangular plates under uniaxial tension using finite element and response surface methods.Design/methodology/approachIn this work, ANSYS software was elected to create the finite element model of the present structure, execute the analysis and generate strain concentration factor (,) data. Response surface method was implemented to formulate a second order equation to precisely compute (,) based on the geometric and material parameters of the present problem.FindingsThe computations of this formula are accurate and in a great agreement with finite element analysis (FEA) data. This equation was further used for obtaining optimum hole and plate designs.Originality/valueAn optimum design of the countersunk hole and the plate that minimizes the (,) value was achieved and hence validated with FEA findings.

NONLINEAR FINITE ELEMENT ANALYSIS OF FRP STRENGTHENED RC BEAMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Experimental Studies ◽  
Material Model ◽  
Element Model ◽  
Steel Reinforcement ◽  
Elastic Model ◽  
Fe Model ◽  
Rc Beams ◽  
Element Analysis

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.

The Grouting Bored Pile Perfusing Pile Bearing Capacity after Effect Factors of the Finite Element Analysis

2012 ◽  
Vol 461 ◽  
pp. 351-354
Author(s):  
Shao He Li ◽  
Qun Xian Lin
Keyword(s):  
Finite Element ◽  
Comparative Analysis ◽  
Bearing Capacity ◽  
Influence Factors ◽  
Element Model ◽  
Model Parameters ◽  
Single Pile ◽  
Element Analysis ◽  
Bored Pile ◽  
After Effect

This article take the Zhejiang some project engineering geology condition as a background, Through comparative analysis with single pile load, determine the model parameters of ANSYS finite element, The ANSYS finite element model of single pile, Respectively on the Grouting pile and Grouting for grouting of pile modulus change and Grouting in body size and changes of modulus of pile-end soils and a series of comparative analysis of the situation and analysis on bearing capacity of bored pile tip Grouting influence factors and of the main causes, draw some useful conclusions.

Finite Element Simulation for Nonlinear Finite Element Analysis of FRP Strengthened RC Beams with Bond-Slip Effect

2016 ◽  
Vol 846 ◽  
pp. 440-445
Author(s):  
Prabin Pathak ◽  
Yi Xia Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Plastic Material ◽  
Element Model ◽  
Elastic Model ◽  
Slip Effect ◽  
Rc Beams ◽  
Element Analysis ◽  
Bond Slip ◽  
Nonlinear Properties

A new simple, efficient and accurate finite element model denoted as FEM-B is developed for the analysis of structural behavior of FRP strengthened RC beams with bond-slip effect. Geometric nonlinearity and material nonlinear properties of concrete and steel rebar are accounted for this model. Concrete, steel, FRP and adhesive are modelled as Solid 65, Link 180, Shell181 and Solid 45 respectively. Concrete is modelled using Nitereka and Neal’s model for compression, isotropic and linear elastic model before cracking for tension and strength gradually reduces to zero after cracking, whereas steel is assumed to be elastic perfectly plastic material. The material of FRP is considered to be linearly elastic until rupture, and adhesive is assumed to be linearly elastic. The bond slip between concrete, adhesive and FRP is based on the bilinear law, which is modelled using spring element Combin 39.The developed new finite element model FEM-B is validated against experimental results, and demonstrates to be effective for the structural analysis of FRP strengthened RC beams.

Optimal Design of Conductor Clamps Based on Abaqus

2014 ◽  
Vol 915-916 ◽  
pp. 244-247
Author(s):  
Kai Liu ◽  
Ming Jiang ◽  
Fei Peng
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Field Test ◽  
Three Dimensional ◽  
Element Model ◽  
Finite Element Models ◽  
Element Analysis ◽  
Optimal Target ◽  
Three Dimensional Models

Three dimensional models and finite element models of conductor clamps are built in software Solidworks and Abaqus. Different forces are loaded on finite element model of conductor clamps to obtain distributions of stress and displacement. Optimal design of conductor clamps is performed with finite element analysis and field test data. The results show that optimal design scheme achieves optimal target.

Agricultural aircraft wing slat tolerance for bird strike

2017 ◽  
Vol 89 (4) ◽  
pp. 590-598 ◽  
Author(s):  
Adam Deskiewicz ◽  
Rafał Perz
Keyword(s):  
Finite Element ◽  
Impact Velocity ◽  
Structural Response ◽  
Element Model ◽  
Bird Strike ◽  
Element Analysis ◽  
Content Type ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
The Impact

Purpose The aim of this study is to assess and describe possible consequences of a bird strike on a Polish-designed PZL-106 Kruk agricultural aircraft. Due to its susceptibility to such events, a wing slat has been chosen for analysis. Design/methodology/approach Smooth particle hydrodynamics (SPH) formulation has been used for generation of the bird finite element model. The simulations were performed by the LS-Dyna explicit finite element analysis software. Several test cases have been analysed with differing parameters such as impact velocity, initial velocity vector direction, place of impact and bird mass. Findings Results of this study reveal that the structure remains safe after an impact at the velocity of 25 m/s. The influence of bird mass on slat damage is clearly observable when the impact velocity rises to 60 m/s. Another important finding was that in each case where the part did not withstand the applied load, it was the lug where first failure occurred. Some of the analysed cases indicated the possibility a consequent wing box damage. Practical implications This finding provides the manufacturer an important insight into the behaviour of the slat and suggests that more detailed analysis of the current lug design might improve the safety of the structure. Originality/value Even though similar analyses have been performed, they tended to focus on large transport aircraft components. This investigation will enhance our understanding of structural response of small, low-speed aircraft to a bird impact, which is a realistic scenario for the chosen case of an agricultural plane.

Model updating of finite element model using optimisation routine

2016 ◽  
Vol 88 (5) ◽  
pp. 665-675 ◽  
Author(s):  
Bimo Prananta ◽  
Toni Kanakis ◽  
Jos Vankan ◽  
Rien van Houten
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Objective Function ◽  
Mode Shape ◽  
Model Updating ◽  
Element Model ◽  
Design Parameters ◽  
Shape Error ◽  
Content Type ◽  
Small Aircraft

Purpose The present paper aims to describe the model updating of a small aircraft dynamic finite element model (FEM) to improve its agreement with ground vibration test (GVT) data. Design/methodology/approach An automatic updating method using an optimization procedure is carried out. Instead of using dedicated updating tools, the procedure is implemented using standard MSC/NASTRAN because of wide availability of the software in small aircraft industries. The objective function is defined to minimize the differences in the natural frequency and the differences in the mode shape between the analytical model and the GVT data. Provision has been made to include the quantification of confidence in both the GVT data and in the initial model. Parameter grouping is carried out to reduce the number of design parameters during the optimization process. Findings The optimization module of standard finite element (FE) software can be effectively used to reduce the differences between the GVT and the FEM in terms of frequency and mode shape satisfactorily. The strategy to define the objective function based on minimizing the mode shape error can reduce the improvement in the frequency error. The required user interference can be kept low. Originality/value The most important contribution of the present paper concerns the combination of strategies to define the objective function and selection of the parameters.

Finite-element modelling of multilayer X-ray optics

2017 ◽  
Vol 24 (3) ◽  
pp. 717-724
Author(s):  
Xianchao Cheng ◽  
Lin Zhang
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Photon Flux ◽  
Attractive Alternative ◽  
Geometrical Parameters ◽  
X Rays ◽  
Element Analysis ◽  
Ray Optics ◽  
X Ray ◽  
Fea Model

Multilayer optical elements for hard X-rays are an attractive alternative to crystals whenever high photon flux and moderate energy resolution are required. Prediction of the temperature, strain and stress distribution in the multilayer optics is essential in designing the cooling scheme and optimizing geometrical parameters for multilayer optics. The finite-element analysis (FEA) model of the multilayer optics is a well established tool for doing so. Multilayers used in X-ray optics typically consist of hundreds of periods of two types of materials. The thickness of one period is a few nanometers. Most multilayers are coated on silicon substrates of typical size 60 mm × 60 mm × 100–300 mm. The high aspect ratio between the size of the optics and the thickness of the multilayer (107) can lead to a huge number of elements for the finite-element model. For instance, meshing by the size of the layers will require more than 1016 elements, which is an impossible task for present-day computers. Conversely, meshing by the size of the substrate will produce a too high element shape ratio (element geometry width/height > 106), which causes low solution accuracy; and the number of elements is still very large (106). In this work, by use of ANSYS layer-functioned elements, a thermal-structural FEA model has been implemented for multilayer X-ray optics. The possible number of layers that can be computed by presently available computers is increased considerably.

Finite Element Analysis and Optimum Design of Octagon Horizontal Type Vacuum Tank

2012 ◽  
Vol 472-475 ◽  
pp. 575-578
Author(s):  
Bing Chuan Bian ◽  
Ai Mei Zhang ◽  
Zhen Long Shang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Optimal Design ◽  
Finite Element Model ◽  
Element Model ◽  
Optimization Models ◽  
Element Analysis ◽  
Horizontal Type ◽  
Strength And Stiffness ◽  
Displacement Constraints

Finite element model for octagon horizontal type vacuum tank was constructed based on the CAD/CAE software SolidWorks. The strength and stiffness of vacuum tank were analyzed. In order to optimize the size of vacuum tank stiffeners by the FEM and optimal design module, the optimization models were constructed, which have the minimized mass as the objective function subjected to the stress and displacement constraints. The results of optimal design were applied to actual production.

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