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.

scholarly journals A Study on the Stress Concentration Factor Induced in Double Countersunk Holes Due to Uniaxial Tension

2020 ◽  
Vol 25 (4) ◽  
pp. 59-68
Author(s):  
Mohammad A. Gharaibeh
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Response Surface ◽  
Uniaxial Tension ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Rectangular Plates ◽  
Least Squares Regression ◽  
Effective Equation ◽  
Element Analysis

AbstractFinite element and response surface methods were utilized to investigate the stress concentration factor induced in isotropic rectangular plates with two identical countersunk rivet holes due to uniaxial tension. In this investigation, the finite element model was constructed using ANSYS software and used to produce stress concentration factor (SCF) data. Additionally, the response surface method (RSM) was implemented to characterize the influence of the problem geometric parameters on the SCF. Besides, RSM combined with least squares regression methods were employed to formulate a simple and effective equation to mathematically compute the stress concentration factor (Kt) value. This equation was consequently verified with finite element analysis (FEA) results. Lastly, an optimum plate and holes configuration that minimizes the SCF was suggested and hence recommended.

The Multi-Objective Optimization of the Planet Carrier in Wind Turbine Gearbox

2012 ◽  
Vol 184-185 ◽  
pp. 565-569 ◽  
Author(s):  
Peng Xing Yi ◽  
Li Jian Dong ◽  
Yuan Xin Chen
Keyword(s):  
Finite Element ◽  
Design Optimization ◽  
Response Surface ◽  
Minimum Principle ◽  
Element Model ◽  
Multi Objective Optimization ◽  
Wind Turbine Gearbox ◽  
Element Analysis ◽  
Multi Objective ◽  
Planet Carrier

In order to improve the reliability of a planet carrier, a simulation method based on multi-objective design optimization was developed in this paper. The objective of the method was to reduce the stress concentration, the deformation, and the quality of the planet carrier by optimizing the structure dimension. A parametric finite element model, which enables a good understanding of how the parameters affect the reliability of planet carrier, was established and simulated by ANSYS-WORKBENCH. The efficiency of the design optimization was improved by using a polynomials response surface to approximate the results of finite element analysis and a screening algorithm to determine the direction of optimization. Furthermore, the multi-objective optimization was capable of finding the global minimum results in the use of the minimum principle on the response surface. Computer simulation was carried out to verify the validity of the presented optimization method, by which the quality and the stability of the planet carrier were significantly reduced and improved, respectively. The methodology described in this paper can be effectively used to improve the reliability of planet carrier.

A three‐dimensional strain concentration equation for countersunk holes

2008 ◽  
Vol 43 (2) ◽  
pp. 75-85 ◽  
Author(s):  
A Bhargava ◽  
K N Shivakumar
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Concentration Factor ◽  
Three Dimensional ◽  
Structural Elements ◽  
Element Analysis ◽  
Strain Concentration ◽  
Wide Range ◽  
Dimensional Equation ◽  
Concentration Equation

Countersunk rivets are used to join components to achieve aerodynamic or hydrodynamic surfaces. At countersunk holes, three‐dimensional stress and strain concentrations occur. Previously, the present authors developed a three‐dimensional equation for the stress concentration factor Kt through a detailed finite element analysis. This paper extends the study to include an equation for three‐dimensional strain concentration factor Ktε using a similar approach. The resulting equation was verified by finite element analysis for a wide range of countersunk hole configurations and plate sizes. Results showed that the maximum strain concentration is at the countersunk edge. The developed equation is within 5 per cent of the finite element results for all practical cases. It was also found that the Ktε and Kt expressions are similar and Ktε≥ Kt. The maximum difference between the two is 8 per cent (for = 0.3) or 2 for straight‐shank holes and about 2/2 for countersunk holes. The proposed equation is a valuable tool for strain‐based design of structural elements.

Parameter optimization of sealing performance for packer rubber

2019 ◽  
Vol 71 (5) ◽  
pp. 664-671
Author(s):  
Fuying Zhang ◽  
Hao Che Shui ◽  
Yufei Zhang
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Response Surface ◽  
Inclination Angle ◽  
Rubber Tube ◽  
Test Results ◽  
Element Analysis ◽  
Content Type ◽  
Sealing Performance ◽  
Maximum Contact

Purpose The purpose of this paper is based on the response surface method, the authors determined the conditions for achieving the optimum rubber-sealing performance by using the maximum contact stress as the response value. Design/methodology/approach A two-dimensional model of a compression packer rubber was established by finite-element analysis software. Under the single axial load of 53.85 MPa, the four single factors of the end-face inclination angle, subthickness, height of rubber and friction coefficient of the rubber were analyzed. Findings Results show that the optimum sealing performance of the rubber tube is achieved when the end-face angle is equal to 45º and the thickness of the rubber tube is 9 mm. The response surface designed by Box–Behnken shows that the sealing performance of the rubber tube is the optimum when the end-face inclination angle is 48.1818°, the subthickness is 9 mm, the height of rubber is 90 mm and the friction coefficient is 0.1. Verification test results show that the model is reliable and effective. Originality/value Packer operations are performed downhole, and research on real experiments is limited. In this work, the feasibility of such experiments is determined by comparing finite-element modeling with actual experiments, and the results have guiding significance for actual downhole operations.

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.

Study of a harmonic drive with involute profile flexspline by two-dimensional finite element analysis

2017 ◽  
Vol 34 (7) ◽  
pp. 2107-2130 ◽  
Author(s):  
Yi-Cheng Chen ◽  
Yun-Hao Cheng ◽  
Jui-Tang Tseng ◽  
Kun-Ju Hsieh
Keyword(s):  
Finite Element ◽  
Mesh Generation ◽  
Element Model ◽  
Tooth Profile ◽  
Two Dimensional ◽  
Harmonic Drive ◽  
Element Analysis ◽  
Content Type ◽  
The Mathematical Model ◽  
The Finite Element Model

Purpose This paper aims to present simulation results of a harmonic drive (HD) with involute flexspline (FS) profiles based on two-dimensional (2-D) finite element analysis (FEA). Design/methodology/approach First, the mathematical model of the FS with involute tooth profile was developed using a straight-edge rack cutter based on the theory of gearing. Then the engaging circular spline (CS) with conjugate tooth profile of FS was derived based on the enveloping theory and theory of gearing. Additionally, a mesh generation program was developed to discretize the FS based on the mathematical model. An elliptical wave generator (WG) was inserted into the FS, and a torque was applied to drive the FS meshing with the CS. The WG and the CS were both assumed to be rigid in the finite element model. Findings Finally, a 2-D FEA was conducted to explore the stress distribution on the FS, the engagement movement of the FS, the torsional stiffness and the engaged area of teeth of the HD under various conditions. Moreover, this research also studied the effect of changing pressure angle of the involute FS on the performance of the HD. Research limitations/implications The simulation model and methodology presented in this paper paved the way for further investigation and optimization of the HD with involute tooth profile FS and conjugate CS. Originality/value The simulation model of HD is established on conjugate shape based on the theory of gearing and an automatic mesh generation program is developed to generate the finite element model. The characteristics of the HD can thus be simulated according to the developed model.

Finite element analysis of CFRP-externally strengthened reinforced concrete beams subjected to three-point bending

2019 ◽  
Vol 17 (2) ◽  
pp. 183-202
Author(s):  
Sabiha Barour ◽  
Abdesselam Zergua ◽  
Farid Bouziadi ◽  
Waleed Abed Jasim
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Comparative Study ◽  
Finite Element Model ◽  
Element Model ◽  
Analytical Models ◽  
Element Analysis ◽  
Content Type ◽  
Linear Finite Element ◽  
Non Linear

Purpose This paper aims to develop a non-linear finite element model predicting the response of externally strengthened beams under a three-point flexure test. Design/methodology/approach The ANSYS software is used for modeling. SOILD65, LINK180, SHELL181 and SOLID185 elements are used, respectively, to model concrete, steel reinforcement, polymer and steel plate support. A parametric study was carried out. The effects of compressive strength, Young’s modulus, layers number and carbon fiber-reinforced polymer thickness on beam behavior are analyzed. A comparative study between the non-linear finite element and analytical models, including the ACI 440.2 R-08 model, and experimental data is also carried out. Findings A comparative study of the non-linear finite element results with analytical models, including the ACI 440.2 R-08 model and experimental data for different parameters, shows that the strengthened beams possessed better resistance to cracks. In general, the finite element model’s results are in good agreement with the experimental test data. Practical implications This model will predict the strengthened beams behavior and can describe the beams physical conditions, yielding the results that can be interpreted in the structural study context without using a laboratory testing. Originality/value On the basis of the results, a good match is found between the model results and experimental data at all stages of loading the tested samples. Crack models obtained in the non-linear finite element model in the beams are also presented. The submitted finite element model can be used to predict the behavior of the reinforced concrete beam. Also, the comparative study between an analytical model proposed by of current code of ACI 440.2 R-08 and finite element analysis is investigated.

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.

Sign in / Sign up

Export Citation Format

Share Document