3-D FEM Stress Analysis and Mechanical Characteristics in Bolted Joints Under External Tensile Loadings

2015 ◽  
Author(s):  
Shunichiro Sawa ◽  
Mitsutoshi Ishimura ◽  
Yasuhisa Sekiguchi ◽  
Toshiyuki Sawa
Keyword(s):  
Maximum Stress ◽  
Three Dimensional ◽  
Bolted Joints ◽  
Nominal Diameter ◽  
Bolt Preload ◽  
Dimensional Finite Element ◽  
M 12 ◽  
Stress States ◽  
Three Dimensional Finite Element ◽  
Screw Threads

In practical design for bolted joints, the stress concentration factor (SCF) of the first root in screw threads is important. In the present paper, the SCF in screw threads taking account of spiral in the screw threads is analyzed using three-dimensional Finite Element Method (FEM). In addition, the stress states of screw threads under repeated and static loadings are analyzed in elasto-plastic deformation range. The effect of bolt nominal diameter (M12, M24 and M33) on SCF is also examined. In addition, the experiment to measure the strains at the roots of screw threads was carried out newly. It is found that the FEM result is fairly coincided with the measured results. It is also found that the SCF increases as the bolt nominal diameter increases and the maximum stress is found to occur at the half pith from the engaged screw threads. The value of SCF is smaller in the coarse screw threads of M12 than that in the fine screw threads of M 12. Finally, the bolt ruptures for several nominal diameters are shown to occur from screw threads in the non-engagement in bolted joints under static loadings and under the repeated loadings the bolts are ruptured from the first root of screw threads due to fatigue even if the bolt preload is the higher.

Study on the critical loosening condition toward a new design guideline for bolted joints

2018 ◽  
Vol 233 (9) ◽  
pp. 3302-3316 ◽  
Author(s):  
Hao Gong ◽  
Jianhua Liu ◽  
Xiaoyu Ding
Keyword(s):  
Three Dimensional ◽  
Element Model ◽  
Simulation Method ◽  
Bolted Joints ◽  
Design Guideline ◽  
Factors Affecting ◽  
Dimensional Finite Element ◽  
Frictional Coefficients ◽  
Three Dimensional Finite Element ◽  
Fit Tolerance

An understanding of conditions that trigger the loosening of bolted joints is essential to ensure joint reliability. In this study, a three-dimensional finite element model of a typical bolted joint is developed, and a new simulation method is proposed to quantitatively identify the critical transverse force for initiating loosening. This force is used to evaluate the anti-loosening capacity of bolted joints. Using the proposed simulation method, the effects of factors affecting critical loosening are systematically studied. It is found that the preload, frictional coefficients at the thread and the bearing surfaces, clamped length, and fit tolerance mainly affected loosening. When the preload and friction coefficients are increased, and the clamped length and fit tolerance are reduced, loosening is inhibited. Experiments are performed to demonstrate the reliability of the results. Finally, a suggestion is proposed to improve the design guideline VDI 2230 for bolted joints, which considers the requirement of avoiding loosening under vibrational loading.

Experimental and numerical studies of bolted joints subjected to torsional excitation

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840083 ◽  
Author(s):  
Xuetong Liu ◽  
Jianhua Liu ◽  
Huajiang Ouyang ◽  
Zhenbing Cai ◽  
Jinfang Peng ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Hysteresis Loops ◽  
Element Model ◽  
Bolted Joints ◽  
Torsional Angle ◽  
Numerical Studies ◽  
Dimensional Finite Element ◽  
Torsional Excitation ◽  
Three Dimensional Finite Element ◽  
Angular Amplitude

The dynamic response of bolted joints subjected to torsional excitation is investigated experimentally and numerically. First, the effects of the initial preload and the angular amplitude on axial force loss of the bolt were studied. Second, the change of hysteresis loops with the increasing number of loading cycles was found under a larger torsional angle. At last, a fine-meshed three-dimensional finite element model was built to simulate the bolted joint under torsional excitation, from which the hysteresis loops were obtained under varying angular amplitudes. The results of numerical analysis are in good agreement with those of experiments.

Three-Dimensional Finite Element Analysis of Implants with Different Crown-to-Root Ratio and Different High Thread

2014 ◽  
Vol 518 ◽  
pp. 190-195
Author(s):  
Ying Jie Duan ◽  
Ling Chen ◽  
Tao Xiong ◽  
Xing Hua Niu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Maximum Stress ◽  
Geometric Model ◽  
Three Dimensional ◽  
Element Analysis ◽  
Jaw Bone ◽  
Crown Root ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

To compare the strain and stress distribution on jaw bone around the implant with different crown-root and different teeth high in teeth repairing, three-dimensional geometric model of the implant was created and analyzed through UG and finite element analysis software. Model came to workbench software after it was drawn and assembly by 3D mapping software of UG. Given material properties of the model, meshing, boundary conditions and forces applied for analysis. It was Obtained that the size and distribution of stress and strain about jaw bone and implant under different conditions. The influence of jaw bone and implant in different conditions was discussed. The main results of the study are as follows: different implant and crown-root, maximum stress with the crown-root increases, but the maximum stress is placid. Factor in the high thread where the maximum stress with high thread show an inverted "U" shape, the maximum strain with high thread becomes flat.

Load Transfer Analysis of Cracked Bolted Joints

2010 ◽  
Vol 118-120 ◽  
pp. 147-150
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Yong Gao ◽  
Wen Lin Liu ◽  
Zhong Hu Jia
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Load Transfer ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a cracked bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of load transfer were compared with results from finite element analysis. The results show that three-dimensional finite element model of cracked bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of hole mod and crack on the load transfer behaviour of single lap bolted joints. The results show that hole mode has big effect on load transfer of cracked bolted joint. In the whole progress of crack growth, the load transfer through bolt 1 decrease, and almost all of the load duduction of bolt 1 transfer into blot 2 rather than into bolt 3.

Mechanics Research with Prediction on the Fatigue Life of the Five-Cylinder Emulsion Pump Crankshaft

2013 ◽  
Vol 738 ◽  
pp. 163-166 ◽  
Author(s):  
Li Ran
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Working Conditions ◽  
Maximum Stress ◽  
Fatigue Crack Initiation ◽  
Three Dimensional ◽  
Finite Element Analyses ◽  
Mechanics Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

In this paper, dynamic mechanics analysis was performed, in order to investigate the maximum forces acting on the crankshaft under working conditions. Then, three dimensional, finite element analyses have been conducted, in an attempt to predict the fatigue crack-initiation locations and lives. The maximum loadings, used in finite element analyses, were analytical obtained, which correspond to the five critical rotational angles of the first crankpin, i.e. = 40 º, 110º, 185 º, 255 º, 325 º. The maximum stress site was found to be approximately on the fillet of the first main journal of the crankshaft. The predicted fatigue life of the crankshafts was obtained by use of a stress-life (S-N) approach.

Experimental and numerical analyses of the shimming effect on bolted joints with nonuniform gaps

2018 ◽  
Vol 233 (11) ◽  
pp. 3964-3975
Author(s):  
Liang Cheng ◽  
Qing Wang ◽  
Yinglin Ke
Keyword(s):  
Control Method ◽  
Load Capacity ◽  
Three Dimensional ◽  
Joint Stiffness ◽  
Element Model ◽  
Bolted Joints ◽  
Aircraft Assembly ◽  
Dimensional Finite Element ◽  
Joint Load ◽  
Three Dimensional Finite Element

In order to investigate the effect of shim compensation for nonuniform gaps in aircraft assembly, the influence of the shims with different material and parameters on bolted joints is studied in this paper. According to the real material and assembly conditions of the aircraft joint structures, the specimen and experiment are designed to obtain the tensile performance of the joint structures with different shims. A three-dimensional finite element model, which incorporates the Johnson–Cook material property of the alloys, traction-separation law of liquid shims, contact relationships between the joint elements, and boundary conditions of the tensile process, is established with the specimen configurations. After validating through comparing with the experimental results, the modeling method is adopted to simulate the tensile response of the bolted joints with shims. Furthermore, both the influence of the shim material and thickness on the mechanical behaviors of bolted joints is investigated in detail. Shims can considerably reduce the assembly stress of joint structures and improve the joint stiffness and load capacity, and this effect is more remarkable with the increase of gap values. Liquid shims improve the joint stiffness due to its cohesive ability, while solid shims improve the joint load capacity. Hybrid shims possess a composite shimming effect of liquid and solid shims. Whatever the shim material is applied, the joint stiffness and strength drop with the growth of shim thickness, so strict deviation control method should be taken to ensure the assembly gaps as small as possible. The research results enhance the knowledge of shimming effect on joint structures, and thus offer positive guidance for practical application in aircraft assembly.

Three-Dimensional Finite Element Analysis Used to Compare Six Different Methods of Syndesmosis Fixation with 3.5- or 4.5-mm Titanium Screws

2013 ◽  
Vol 103 (3) ◽  
pp. 174-180 ◽  
Author(s):  
Mehmet Serhan Er ◽  
Ozgur Verim ◽  
Levent Altinel ◽  
Suleyman Tasgetiren
Keyword(s):  
Finite Element ◽  
Maximum Stress ◽  
Three Dimensional ◽  
Element Model ◽  
Element Analysis ◽  
Computed Tomographic ◽  
Cortical Screw ◽  
Titanium Screws ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Background: Use of thicker and longer (four cortices) screws or of multiple screws seems to be more stable and efficient for syndesmosis fixation. Methods: A three-dimensional finite element model of an ankle was constructed from serial axial sections from an existing two-dimensional computed tomographic image. Constructions of syndesmosis fixation with 3.5-mm single tricortical, 3.5-mm single quadricortical, 3.5-mm double tricortical, 3.5-mm double quadricortical, 4.5-mm single tricortical, and 4.5-mm single quadricortical screws were performed on this model. Physiologic loads approximating those during stance phase normal walking were applied to this ankle system. Stress values on the screws using the six fixation methods were compared. Results: The highest maximum stress was determined over 3.5-mm cortical screws applied as single quadricortical, and the lowest maximum stress was determined over the 4.5-mm cortical screw applied as single quadricortical. Stress on the 3.5-mm single screw with quadricortical application was found to be higher than that with tricortical application and also compared with the 4.5-mm quadricortical screw application. Differences between the 4.5-mm single tricortical and quadricortical screws and between the 3.5-mm single tricortical and 3.5-mm double tricortical screw applications were not significant. Conclusions: Quadricortical application of 3.5-mm single screws and tricortical application of 3.5-mm double cortical screws are not good choices for syndesmosis fixation. If the plan is tricortical application, a 3.5-mm single cortical screw is adequate. If quadricortical application of syndesmosis fixation is planned, a 4.5-mm cortical screw should be used. (J Am Podiatr Med Assoc 103(3): 174–180, 2013)

Parametric Analysis Mechanical Properties of Bolted Joints

2010 ◽  
Vol 97-101 ◽  
pp. 3924-3927 ◽  
Author(s):  
Da Zhao Yu ◽  
Yue Liang Chen ◽  
Zhong Hu Jia ◽  
Yong Gao ◽  
Wen Lin Liu
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Three Dimensional ◽  
Element Model ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Three-dimensional finite element model of a bolted joint has been developed in the non-linear finite element code MSC.Marc and attempts were made to validate it by comparing results with those of experiments and other finite element. Issues in modeling the contact between the joint parts, which affect the accuracy and efficiency of the model, were presented. Experimental measurements of surface strains and load transfer ratio(LTR) were compared with results from finite element analysis. The results show that three-dimensional finite element model of bolted joint can produce results in close agreement with experiment. Three-dimensional effects such as bolt titling, seconding and through-thickness variations in stress and strain are well represented by such models. Three-dimensional finite element analysis was also used to study the effects of different parameters on the mechanical behaviour of single lap bolted joints. The results show that straight hole, small bolt diameter, and big hole pitch are selected first for bolted joint if other conditions allowed, and effect of bolt material on LTR of joint is small for small load. Interference and pre-stress should be strictly controlled for bolted joints in order to attain the best fatigue capability of lap joint.

A Parametric Study on Particulate Al-SiC Composite Bolted Joints

2006 ◽  
Author(s):  
Samir N. Shoukry ◽  
Jacky C. Prucz ◽  
Gergis W. William
Keyword(s):  
Load Transfer ◽  
Three Dimensional ◽  
Closed Form Solution ◽  
Lap Joints ◽  
Form Solution ◽  
Bolted Joints ◽  
Design Parameters ◽  
Dimensional Finite Element ◽  
Sliding Interfaces ◽  
Three Dimensional Finite Element

The main objective of this study is to predict theoretically the stress distributions around the holes in a bolted joint made of particulate metal matrix composite and to investigate the associated load transfer efficiencies both for a single and double lap bolted joints. A three-dimensional finite element parametric model has been developed to examine the effects of various design parameters on the structural performance of such joints. The main feature of this model is explicit modeling of the sliding interfaces between the connected plates and the washers, and those between the hole and the bolt. The model response showed an excellent agreement with a closed form solution as well as experimental data. The results indicated that unsymmetric configuration of single lap joints causes bending as the load is applied, which is opposite of the double lap joints. This research quantifies the relationship between the stress developed around the hole and washer diameter, tightening pressure, and clearance between the bolt and hole. It was also observed that variations in Young's modulus have no significant effect on the stress concentration around the hole.

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