Parametric Analysis for Ultimate Strength Prediction of Stainless Steel Bolted Joints with Single Bolt

2011 ◽  
Vol 255-260 ◽  
pp. 79-83
Author(s):  
Tae Soo Kim ◽  
Jin Seong Lim

A variety of parametric studies utilizing the finite element analysis (FEA) have been performed by Kim et al in order to predict the mechanical behavior(ultimate strength) of single shear bolted joints in cold-formed(thin-walled) stainless steel. The precedent researches have been conducted with respect to the mechanical behaviors of single shear bolted joints fabricated with four bolts and two bolts. Subsequently, this study has been focused on the comparison of ultimate behaviors between the existing test results and FEA results. In addition, parametric study has been performed in order to investigate the influence of mesh size and washer existence on ultimate behaviors. Therefore, reasonable finite element modelling method and condition were recommended in this paper.

2012 ◽  
Vol 446-449 ◽  
pp. 3441-3445 ◽  
Author(s):  
Tae Soo Kim ◽  
Yong Hyun Jo ◽  
Seung Hun Kim ◽  
Yong Taeg Lee

The purpose of this study is to investigate the ultimate behaviors of aluminum alloy bolted connections assembled with four bolts. Specimens for single shear bolted connections were tested and finite element analysis based on this test results was conducted. The validity of finite element(FE) analysis for predicting the structural behaviors such as ultimate strength, fracture mode and curling(out-of-plane deformation) occurrence was verified through the comparisons between test results and FE analysis results. It is known that the curling resulted in sudden strength drop. Moreover, FE models with free edge and restrained out-of-plane deformation for curled specimens are analyzed additionally, therefore, the influence of curling on the ultimate strength; strength reduction ratio is estimated.


2013 ◽  
Vol 658 ◽  
pp. 350-353
Author(s):  
Tae Soo Kim ◽  
Min Seung Kim ◽  
Sung Woo Shin

Since stainless steel has significant characteristics such as its superior corrosion resistance, durability, aesthetic appeal etc., it has been utilized as structural members in buildings. Recently, ultimate behaviors and curling influence in austenitic stainless steel single shear bolted connections with thin-walled plane plates have been investigated by T.S. Kim. In this paper, finite element analysis (FEA) has been conducted based on the existing test results of angle bolted connections in fabricated with austenitic stainless steel. The validation of the numerical analysis prediction was verified through the comparison of test results for fracture mode, ultimate strength and curling occurrence. Curling (out-of- plane deformation) also observed in the connections with a long end distance. The curling caused the ultimate strength reduction and the ultimate strength reduction ratios (varied from 12% to 25%) caused by curling have been estimated quantitatively through the comparison of FEA results of FE models with free edge and restrained curling.


2010 ◽  
Vol 452-453 ◽  
pp. 613-616 ◽  
Author(s):  
Yong Taeg Lee ◽  
Tae Soo Kim ◽  
Jin Seong Lim ◽  
Seung Hun Kim

The experimental research for single shear bolted connection of cold-formed stainless steel fabricated with two bolts (2×1 bolt arrangement) has been conducted by T.S. Kim etc. Plate thickness and end distance parallel to the direction of loading was considered as main variables. It is found that the curling occurred easily in bolted connections with a long end distance and thinner plate. In this paper, finite element analysis study has been performed in order to compare test results with the predicted results and to investigate in detail the ultimate strength and curling influence. Finite element analysis(FEA) procedures also were introduced. FE models of connections with restrained out of plane deformation were also simulated for comparison with the curled models. Therefore, the validation of FEA in predicting ultimate strength and curling behavior was verified and the strength reduction ratio caused by curling was estimated.


1983 ◽  
Vol 105 (2) ◽  
pp. 206-212 ◽  
Author(s):  
Hua-Ping Li ◽  
F. Ellyin

A plate weakened by an oblique penetration of a circular cylindrical hole has been investigated. The stress concentration around the hole is determined by a finite-element method. The results are compared with experimental data and other analytical works. Parametric studies of effects of angle of inclination, plate thickness, and width are performed. The maximum stress concentration factor (SCF) obtained from the finite-element analysis is higher than experimental results, and this deviation increases with the increase of angle of skewness. The major reason for this difference is attributed to the shear-action between layers parallel to the plate surface which cannot be directly included in the two-dimensional elements. An empirical formula is derived which accounts for the shear-action and renders the finite-element predictions in line with experimentally observed data.


2011 ◽  
Vol 213 ◽  
pp. 419-426
Author(s):  
M.M. Rahman ◽  
Hemin M. Mohyaldeen ◽  
M.M. Noor ◽  
K. Kadirgama ◽  
Rosli A. Bakar

Modeling and simulation are indispensable when dealing with complex engineering systems. This study deals with intelligent techniques modeling for linear response of suspension arm. The finite element analysis and Radial Basis Function Neural Network (RBFNN) technique is used to predict the response of suspension arm. The linear static analysis was performed utilizing the finite element analysis code. The neural network model has 3 inputs representing the load, mesh size and material while 4 output representing the maximum displacement, maximum Principal stress, von Mises and Tresca. Finally, regression analysis between finite element results and values predicted by the neural network model was made. It can be seen that the RBFNN proposed approach was found to be highly effective with least error in identification of stress-displacement of suspension arm. Simulated results show that RBF can be very successively used for reduction of the effort and time required to predict the stress-displacement response of suspension arm as FE methods usually deal with only a single problem for each run.


2000 ◽  
Vol 13 (02) ◽  
pp. 65-72 ◽  
Author(s):  
R. Shahar

SummaryThe use of acrylic connecting bars in external fixators has become widespread in veterinary orthopaedics. One of the main advantages of an acrylic connecting bar is the ability to contour it into a curved shape. This allows the surgeon to place the transcortical pins according to safety and convenience considerations, without being bound by the requirement of the standard stainless steel connecting bar, that all transcortical pins be in the same plane.The purpose of this study was to evaluate the stiffness of unilateral and bilateral medium-sized external fixator frames with different curvatures of acrylic connecting bars. Finite element analysis was used to model the various frames and obtain their stiffness under four types of load: Axial compression, four-point medio-lateral bending, fourpoint antero-posterior bending and torsion. The analysis also provided the maximal pin stresses occurring in each frame for each loading condition.Based on the results of this study, curvatures of acrylic connecting bars of up to a maximal angular difference between pins of 25° will result in very similar stiffness and maximal pin stresses to those of the equivalent, uniplanar stainless steel system. In both unilateral and bilateral systems the stiffness decreases slightly as angulation increases for axial compression and medio-lateral bending, increases slightly for torsion and increases substantially for antero-posterior bending.External fixator systems with curved acrylic connecting bars are commonly used in veterinary orthopaedics. This paper evaluates the biomechanical performance of such systems by applying the finite element analysis method. It shows that external fixators with curved acrylic connecting bars exhibit stiffness and maximal pin stresses which are similar to those of the standard stainless steel system.


Author(s):  
Yasumasa Shoji ◽  
Toshiyuki Sawa ◽  
Hiroshi Yamanaka

As self-loosening of nuts is really a problem for bolted joints in practical use, countermeasures for the loosening is highly required. In this situation non-loosening fasteners are one of the resolutions for any fastened machinery as an essential mechanical element. Self-loosening of threaded bolt/nut systems has been researched in number of works and most researches were based on experiment and a few were based on the finite element analysis in these years. Using this new approach, various types of nuts can also be examined. Among these nuts eccentric nuts and slit nuts are especially expected to be the solution, as these nuts are reported to endure NAS vibration tests and were not loosened. In the authors’ previous paper, an eccentric nut and a normal nut were analyzed and compared in the aspect of loosening property. In this paper degree of loosening of various nuts was investigated by experiment and the FEA.


2009 ◽  
Vol 09 (01) ◽  
pp. 85-106
Author(s):  
N. PRASAD RAO ◽  
S. J. MOHAN ◽  
R. P. ROKADE ◽  
R. BALA GOPAL

The experimental and analytical behavior of 400 kV S/C portal-type guyed towers under different loading conditions is presented. The portal-type tower essentially consists of two masts extending outward in the transverse direction from the beam level to the ground. In addition, two sets of guys connected at the ground level project outward along the longitudinal axes and converge in the transverse axes. The experimental behavior of the guyed tower is compared with the results of finite element analysis. The 400 kV portal-type guyed towers with III and IVI type insulator strings are analyzed using finite element software. Full scale tower test results are verified through comparison with the results of the finite element analysis. The initial prestress in the guys is allowed to vary from 5% to 15% in the finite element modeling. The effect of prestress variation of the guys on the tower behavior is also studied.


2021 ◽  
Author(s):  
Yu-Hsuan Chen ◽  
Kuo-Min Su ◽  
Ming-Tzu Tsai ◽  
Chi-Kung Lin ◽  
Cheng-Chang Chang ◽  
...  

Abstract PurposeIn some cases where operative deliveries are required with vacuum extractor, and obstetricians could choose the vacuum extractor to facilitate the process smoother and safer. However, there is no related biomechanical literature about the influences of vacuum extractors fabricated from different materials and pressures of vacuum on the fetal head. Hence, we utilized the finite element method to investigate the influences of vacuum extractors manufactured from different materials on the fetal head under various extractive pressures.MethodsFirst, the finite element analysis models of vacuum extractor and fetal head were established. The vacuum extractor model was designed as a hemispherical shape and we compared silicone rubber and stainless steel for the materials of vacuum extractor. Subsequently, four different vacuum pressures were applied as the factors for investigation—500-cm H2O, 600-cm H2O, 700-cm H2O, and 800-cm H2O. Finally, we observed and analyzed the reactive force on the fetal head, von Mises stress of vacuum extractor, and von Mises stress on the skull of fetal head to evaluate the influences of vacuum extractors of different materials under different pressures. ResultsThe results demonstrated that different vacuum pressures had only a slight difference of influences on the fetal head. The use of stainless-steel vacuum extractors caused a relatively larger reactive force (358.04–361.37 N) and stress (13.547–13.675 MPa) on the fetal head. ConclusionsNon-metallic or relatively softer materials could be selected when using a vacuum extractor for operative delivery to avoid complications such as scalp scratch, and even cephalohematoma and intracerebral hemorrhage.


2014 ◽  
Vol 697 ◽  
pp. 226-229
Author(s):  
Cai Ling Wang ◽  
Hong Wei Wang

According to flexible connectivity of space stabilization system,This paper proposes the finite element analysis method using multiple equivalent spring connecting unit to replace the original flexible connections. And the elastic coefficient’s correspondence between the equivalent spring and the original spring were deduced. Using the equivalent spring method, the tip/tilt mirror system for finite element modeling is completed, After completion of the modal analysis, first-order resonant frequency is calculated. At last, the tip/tilt mirror system is tested in non-contact laser resonance detection system, And test results and modal analysis results were compared, and results show that the finite element modeling method of using equivalent spring connecting is effective. Provide constructive reference for subsequent tip/tilt mirror design, has a very important reference for similar projects.


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