Stress Analysis of Combination Joints of Adhesive With Tap Bolt Under External Tensile Loads

2002 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Akira Moriuchi
Keyword(s):  
Finite Element Method ◽  
Plastic Deformation ◽  
Stress Distribution ◽  
Adhesive Joints ◽  
Bolted Joints ◽  
Strain Gauges ◽  
Screw Thread ◽  
Clamping Force ◽  
Stress Distributions ◽  
Bolted Joint

The stress distributions in a combination joint of an adhesive with a tap bolt under external tensile loadings are analyzed in elasto-plastic deformation using a finite element method. The FEM code employed is MARC. The effects of the initial clamping force (preload), external loadings and the position of engagement screw thread on the interface stress distributions are analyzed. In addition, the stress distribution in the combination joints of the adhesive with the tap bolt is compared with that in tap bolted joint without an adhesive and the adhesive joints without the tap bolt. As the results, it is found that the stress distribution (compression) in the combination joint is less than that of bolt joints. In addition, the experiments were carried out to measure the strain of the combination joint under external tensile loads using strain gauges. Furthermore, the joint strengths under external loadings were measured. Fairly good agreements are observed between the numerical and the measured results. In addition, the usefulness of the combination joints is demonstrated in comparison with the bolted joints and the adhesive joints.

Member Stiffness and Contact Pressure Distribution of Bolted Joints

1993 ◽  
Author(s):  
Terry F. Lehnhoff ◽  
Kwang-Il Ko ◽  
Matthew L. McKay
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bolted Joints ◽  
Two Dimensional ◽  
Stress Distributions ◽  
Bolted Joint ◽  
Dimensional Problem ◽  
The Finite Element Method ◽  
Contact Pressure Distribution ◽  
Percent Difference

Abstract Member stiffnesses and the stress distributions in the bolts and members of bolted joints have been calculated for various bolt sizes, as well as thicknesses and materials of the members. The finite element method has been used to calculate the displacements and the stress distributions in the components of the bolted joint. Using axisymmetric elements, the bolted joint was analyzed as a two-dimensional problem. Member stiffness ratios were calculated from the finite element results and compared with those calculated by a commonly used theory. The differences in values were significant (16–30 percent difference) for the assumptions under which the theory was applied. Formulas and dimensionless curves which can be used to estimate the member stiffness ratios for several kinds of bolted joints are presented.

Mechanical Behavior of Rotational Screw Thread Loosening in Bolted Joints Under Repeated Temperature Changes

2008 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Mitsutoshi Ishimura ◽  
Yasumasa Shoji ◽  
Yusuke Fukuba
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Experimental Results ◽  
Bolted Joints ◽  
Screw Thread ◽  
Bolted Joint ◽  
Temperature Changes ◽  
Thermal Changes ◽  
The Difference

Bolted joints have been used in mechanical structures. However, loosening accidents sometimes happen under several types of loadings. Recently, some studies have been conducted on the screw thread loosening in bolted joints. It is verified that bolted joints are loosened when transverse repeated loadings are applied. A lot of parts for preventing the loosening in the joints have been proposed. Among these parts, eccentric nut is especially expected to be the solution for preventing the loosening. Some studies on no rotational loosening in bolted joints under thermal changes have also conducted. However, few studies on rotational screw thread loosening in bolted joints have conducted. In our previous study, mechanism of rotational screw thread loosening in bolted joint under repeated temperature changes was examined. However, the difference in the loosening mechanism between the FEM results and the experimental results was substantial. In this study, the effect of the incline at the bearing surfaces was taken into consideration on the loosening. In addition, the loosening in the bolted joint with the eccentric nut under repeated temperature changes was examined using finite element method (FEM) calculations. Discussion is made on the mechanism and a solution of rotational screw thread loosening in the bolted joints under the repeated temperature changes. The results show that a reduction in axial bolt force was increased when the incline at the bearing surfaces was taken into consideration and the eccentric nut was shown for preventing the bolt loosening.

Member Stiffness and Contact Pressure Distribution of Bolted Joints

1994 ◽  
Vol 116 (2) ◽  
pp. 550-557 ◽  
Author(s):  
T. F. Lehnhoff ◽  
Kwang Il Ko ◽  
M. L. McKay
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Bolted Joints ◽  
Two Dimensional ◽  
Stress Distributions ◽  
Bolted Joint ◽  
Dimensional Problem ◽  
The Finite Element Method ◽  
Contact Pressure Distribution ◽  
Percent Difference

Member stiffnesses and the stress distributions in the bolts and members of bolted joints have been calculated for various bolt sizes, as well as thicknesses and materials of the members. The finite element method has been used to calculate the displacement and the stress distributions in the components of the bolted joint. Using axisymmetric elements, the bolted joint could be analyzed as a two-dimensional problem. Member stiffness ratios were calculated from the finite element results and compared with those calculated by a commonly used theory. The values were approximately comparable (16–30 percent difference) for the assumptions under which the theory was applied. Formulas and dimensionless curves which can be used to estimate the member stiffness ratios for several kinds of bolted joints are presented.

Experimental Evaluation of Screw Thread Loosening in Bolted Joint With Some Parts for Preventing the Loosening Under Transverse Repeated Loadings

2006 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Mitsutoshi Ishimura ◽  
Hiroshi Yamanaka
Keyword(s):  
Experimental Evaluation ◽  
Bolted Joints ◽  
Test Machine ◽  
Screw Thread ◽  
Clamping Force ◽  
Bolted Joint

In mechanical structures, a lot of bolts and nuts have been used. Sometimes loosening accidents happen in the structures under several types of loadings. Recently, the cause of the screw thread loosening is being elucidated. However, the effect of some parts for preventing the loosening in bolted joints such as spring washer, double nut and so on is not fully elucidated. In this study, the experiments were carried out to measure the reduction of axial bolt force in the bolted joint with some parts for preventing the loosening such as the spring washer, the toothed washer, the double nuts, the eccentric nut, and so on under the transverse repeated loadings. The test machine used was Junker’s type loosening machine. Then, the effects of the washers and some types of nuts are evaluated on the loosening of bolted joints. It is shown that the performance for loosening is getting better as the initial clamping force increases and the effect of the washers is not found on the loosening. However, the effect of eccentric nut is substantial on the loosening. In addition, the loosening tests according to NAS were also carried out. No effect of all the washers mentioned above is found due to NAS testing. Discussion is made on the effect of the parts for preventing the loosening mentioned above.

Stress Distributions in Nonsymmetric Rotating Rays

1955 ◽  
Vol 22 (3) ◽  
pp. 311-316
Author(s):  
P. G. Hodge
Keyword(s):  
Plastic Deformation ◽  
Stress Distribution ◽  
Large Scale ◽  
Bending Moment ◽  
Rotating Disk ◽  
Longitudinal Force ◽  
Maximum Speed ◽  
Stress Distributions ◽  
Centrifugal Forces

Abstract The centrifugal forces acting upon a rotating ray will produce longitudinal stresses along the ray. If the ray is not symmetric, these stresses will result not only in a longitudinal force, but also in a bending moment. A technique for finding the stress distribution in this case is developed and illustrated by means of simple examples. The limiting elastic speed and the maximum speed before large-scale plastic deformation commences are computed. An indication is given of how similar methods may be used to analyze a rotating disk with no plane of symmetry perpendicular to the axis.

scholarly journals Life analysis of the bolted joint

2019 ◽  
Vol 254 ◽  
pp. 02004
Author(s):  
Milan Sapieta ◽  
Peter Sulka
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Numerical Analysis ◽  
Fatigue Damage ◽  
Computational Models ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Computation Model ◽  
Life Analysis ◽  
Element Method

The paper deals with the fatigue damage calculation of 2 types of computation model of bolted joints. The study is performed via a numerical analysis with support of finite element method (FEM) software ANSYS. One model was created with a thread on the bolt, another was only bolt with cylindrical surfaces, the second model was greatly simplified. It will be evaluated the fatigue damage for both types of models. Subsequently both types of computational models will be compared in dependence on the accuracy of the results and the speed of the calculation. There are also the theoretical backgrounds for preloaded bolted joint, which was used for calculation of preload load prescribed on body of screws.

3-D FEM Stress Analysis of Screw Threads in Bolted Joints Under Static Tensile Loadings

2014 ◽  
Author(s):  
Shunichiro Sawa ◽  
Mitsutoshi Ishimura ◽  
Yuya Omiya ◽  
Toshiyuki Sawa
Keyword(s):  
Plastic Deformation ◽  
Bolted Joints ◽  
Experimental Result ◽  
Screw Thread ◽  
Numerical Result ◽  
Static Tensile ◽  
Hollow Cylinders ◽  
Stress States ◽  
Plastic Deformation Region ◽  
Screw Threads

The stress concentration factor (SCF) for the roots of screw threads in bolted joints under static loadings is analyzed using 3-D elastic FEM taking account the spiral of screw threads. At first, the stress states at the roots of screw threads in initial clamping state in a bolted joint where two hollow cylinders were clamped with a bolt and a nut were analyzed in initial clamping. The elastic FEM result of SCF for the first root was obtained as SCF=3.2. When the bolt was clamped in initial clamping (preload) at the 60 % of bolt yield stress, the plastic deformations were found at the first and the second roots, and non-engaged screw threads. It was found that as the external tensile loads increased, the development in plastic deformation region increased from the first root to the other roots as well as the non-engaged screw threads. It was found that the rupture occurred from the non-engaged screw threaded part while the plastic deformation increased at each root of screw threads. The numerical result was coincided with the experimental result. In the experiments, it was observed that the rupture occurred from the non-engaged screw thread and not from the first root of screw thread. Also, the bolt fatigue was predicted from FEM and it was shown that a fatigue fracture occurred from the first root.

FEM Stress Analyses of the Contact Stress Distributions at the Bearing Surfaces in Bolted Joints Using Hexagon Bolts With Flanges

2010 ◽  
Author(s):  
Yukio Morozumi ◽  
Masahiko Okumura ◽  
Toshiyuki Sawa ◽  
Kengo Kuwaki
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Slope Angle ◽  
Bolted Joints ◽  
Stress Distributions ◽  
Bearing Surface ◽  
Permanent Set ◽  
Flange Thickness ◽  
The Difference ◽  
Contact Stress Distribution

In designing bolted joints, it is important to understand the contact stress distribution and permanent set at the bearing surface in the case of high initial axial tension. They are investigated using elasto-plastic FEM for hexagon bolts with flange. It is found that the difference in the contact stress distribution is large between elastic FEM and elasto-plastic FEM. Effects of the flange thickness and the flange slope angle on the contact stress distribution and permanent set are examined, and it is shown that they are substantially influential. In the experiments, hollow cylindrical specimens are compressed by the bolts with flange and permanent sets are measured at the bearing surface. The permanent sets are compared with permanent sets obtained from the elasto-plastic FEM and they are in a fairly good agreement. In addition, the equivalent length for the hexagon bolt with flange is proposed.

Bolt Load Loss Behavior of Magnesium Alloy AZ91D Bolted Joints Clamped with Aluminum Alloy A5056 Bolt

2013 ◽  
Vol 313-314 ◽  
pp. 135-139
Author(s):  
Supamard Sujatanond ◽  
Yukio Miyashita ◽  
Shinji Hashimura ◽  
Yoshiharu Mutoh ◽  
Yuichi Otsuka
Keyword(s):  
Plastic Deformation ◽  
Thermal Expansion ◽  
Aluminum Alloy ◽  
Magnesium Alloy ◽  
Friction Condition ◽  
Bolted Joints ◽  
Bolted Joint ◽  
Az91d Magnesium Alloy ◽  
Alloy Az91d ◽  
Scm435 Steel

The bolt load loss behavior of AZ91D magnesium alloy bolted joints with a conventional SCM435 steel bolt and an A5056 aluminum bolt was investigated at elevated temperature. The A5056 bolt could reduce the bolt load loss compared to the SCM435 bolt due to smaller mismatch of thermal expansion between the bolt material and the plates. The mismatch of thermal expansion between bolt material and AZ91D plates was found to induce the compressive creep deformation in the AZ91D plates which performed as the main mechanism of bolt load loss. At higher tightening stress, the bolt load loss could be intensified by additional plastic deformation in bolt occurred during the test. Moreover, it is suggested that the plastic deformation could be reduced by decreasing the friction condition in the bolted joint.

Sign in / Sign up

Export Citation Format

Share Document