Analysis of Bonded Shrink Fitted Joints Under Push-Off Forces: The Effect of Joint Size on the Joint Strength

2000 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Masahiro Yoneno ◽  
Yasuo Matsunami
Keyword(s):  
Surface Roughness ◽  
Stress Distribution ◽  
Contact Problem ◽  
Size Effect ◽  
Joint Strength ◽  
Theory Of Elasticity ◽  
Experimental Results ◽  
Outer Diameter ◽  
Body Contact ◽  
Good Agreement

Abstract Shrink fitted joints have been widely used in mechanical structures. Recently, joints combining shrink fitted with an anaerobic adhesive have been developed in order to increase the joint strength. This joint is named the bonded shrink fitted joint. In this paper, push-off tests were carried out to measure the joint strength of bonded shrink fitted joints. In addition, the strength of the shrink fitted joints without the anaerobic adhesive was also measured. In the experiments, the effect of shrinking allowance, the outer diameter of the shafts, and the engagement length on the joint strength are examined. In addition, the size effect of joints is also examined in the experiments taking into account the surface roughness, and the roundness. The stress distribution of the joints subjected to a push-off load is analyzed using axisymmetrical theory of elasticity as a four-body contact problem. Using the stress distribution, the joint strength is estimated. The experimental results are in a fairly good agreement with the numerical results. It is found that the push-off strength of the bonded shrink fitted joints is greater than that of the shrink fitted joint.

New Design Formula for Bolted Joints Under Tensile Loads

2013 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Yuya Omiya
Keyword(s):  
Tensile Load ◽  
Theoretical Background ◽  
Theory Of Elasticity ◽  
Experimental Results ◽  
Spring Constant ◽  
Load Factor ◽  
Outer Diameter ◽  
Hollow Cylinders ◽  
The Difference ◽  
Good Agreement

In designing a bolted joint, it is important to estimate an increment in axial bolt force when an external tensile load is applied to an assembly. The ratio of the increment Ft in the axial bolt force to the external tensile load W is called the load factor φ(= Ft/w). The formula φ = Kt/(Kt+Kc) proposed by Thum has been applied for estimating the value of the load factor φ, where Kt is the spring constant of bolt-nut system and Kc is the compressive spring constant of clamped parts. It has been found that the value of the load factor varies with the position of load application to the assembly. Then, a method to compensate Thum’s formula was proposed. However, this compensation is made empirically and the theoretical background is not made clear. In this paper, the concept of the tensile spring constant Kpt for clamped parts is introduced newly when an external load is applied to the outer circumference of clamped parts (hollow cylinders) and a method for estimating the value of the load factor exactly is proposed by using Kpt. The value of Kpt is analyzed using an axisymmetric theory of elasticity. For verification of the proposed method, experiments were carried out to measure the load factor. A fairly good agreement is seen between the analytical and the experimental results of the values of the load factor while the values of the load factor obtained from Thum’s formula were so different with the experimental results. The reason why the difference in the values of the load factor is substantial between values and the values obtained from Thum’s formula is elucidated. It is found that the value of the load factor decreases as the outer diameter of the hollow cylinder increases and the as thickness of the clamped parts decreases. In addition, FEM calculations for the load factor are carried out. The FEM results are in a fairly good agreement with the theoretical results.

An Analysis of Pipe Flange Connections Using Epoxy Adhesives/Anaerobic Sealant Instead of Gaskets

1995 ◽  
Vol 117 (4) ◽  
pp. 298-304 ◽  
Author(s):  
T. Sawa ◽  
R. Sasaki ◽  
M. Yoneno
Keyword(s):  
Stress Distribution ◽  
Internal Pressure ◽  
Theory Of Elasticity ◽  
Experimental Results ◽  
Clamping Force ◽  
Bonding Force ◽  
Epoxy Adhesives ◽  
Analytical Results ◽  
Sealing Performance ◽  
Circle Diameter

This paper deals with the strength and the sealing performance of pipe flange connections combining the bonding force of adhesives with the clamping force of bolts. The epoxy adhesives or anaerobic sealants are bonded at the interface partially instead of gaskets in pipe flange connections. The stress distribution in the epoxy adhesives (anaerobic sealant), which governs the sealing performance, and the variations in axial bolt force are analyzed, using an axisymmetrical theory of elasticity, when an internal pressure is applied to a connection in which two pipe flanges are clamped together by bolts and nuts with an initial clamping force after being joined by epoxy adhesives or anaerobic sealant. In addition, a method for estimating the strength of the combination connection is demonstrated. Experiments are performed and the analytical results are consistent with the experimental results concerning the variation in axial bolt force and the strength of combination connections. It can be seen that the strength of connections increases with a decrease in the bolt pitch circle diameter. Furthermore, it is seen that the sealing performance of such combination connections in which the interface is bonded partially is improved over that of pipe flange connections with metallic gaskets.

A Stress Analysis of a Taper Hub Flange With a Bolted Flat Cover

1997 ◽  
Vol 119 (3) ◽  
pp. 293-300
Author(s):  
T. Sawa ◽  
N. Higurashi ◽  
T. Hirose
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Theory Of Elasticity ◽  
Load Factor ◽  
Bolted Connection ◽  
Body Contact ◽  
The Moment ◽  
Flat Cover ◽  
The Relationship ◽  
Contact Stress Distribution

A bolted connection consisting of a cover on a pressure vessel flange with a metallic flat gasket on raised faces is analyzed as a four-body contact problem using axisymmetrical theory of elasticity. The contact stress distribution, the load factor (the relationship between an increment of bolt axial force and an internal pressure), and the gasket properties (the gasket seating width and the moment arm) are examined. In the analysis, the cover is replaced with a finite solid cylinder. The metallic flat gasket, the flange, and the hub are replaced with finite solid cylinders. The effects of the stiffness and the thickness of various size gaskets on the contact stress distribution are obtained by numerical calculations. Experiments were carried out to obtain the load factor, the maximum stress produced in bolts, and the stress produced on the hub. The analytical results obtained are shown to be consistent with the experimental results.

An Analysis of Circular Bolted Flanged Joints on Solid Round Bars Subjected to External Bending Moments

2000 ◽  
Author(s):  
Toshiyuki Sawa ◽  
Tsuneshi Morohoshi ◽  
Akihiro Shimizu
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Three Dimensional ◽  
Bending Moment ◽  
Theory Of Elasticity ◽  
Load Factor ◽  
Bending Moments ◽  
Sealing Performance ◽  
Contact Stress Distribution ◽  
Good Agreement

Abstract In designing bolted joints, it is important to know the contact stress distribution which governs the clamping effect or the sealing performance and to estimate the load factor (the ratio of an increment in axial bolt force to an external load) from bolt design standpoint. The clamping force by bolts and the external bending moment are axi-asymmetrical loads and not many investigations have seen reported which treat axi-asymmetrical. In this paper, the clamping effect, and the load factor for the case of solid round bars with circular flanges, subjected to external bending moments, are analyzed as an axi-asymmetrical problem using the three-dimensional theory of elasticity. Experiments were carried out concerning the contact stress distribution, and the load factor for the external bending moment (a relationship between an increment in axial bolt force, and external bending moment). The analytical results were in fairly good agreement with the experimental ones.

Surface Roughness Effects in High-Speed Hydrodynamic Journal Bearings

1997 ◽  
Vol 119 (4) ◽  
pp. 776-780 ◽  
Author(s):  
H. Hashimoto
Keyword(s):  
Surface Roughness ◽  
High Speed ◽  
Reynolds Equation ◽  
Computation Time ◽  
Experimental Results ◽  
Roughness Effects ◽  
Modified Reynolds Equation ◽  
Nonlinear Simultaneous Equations ◽  
Theoretical Results ◽  
Good Agreement

This paper describes an applicability of modified Reynolds equation considering the combined effects of turbulence and surface roughness, which was derived by Hashimoto and Wada (1989), to high-speed journal bearing analysis by comparing the theoretical results with experimental ones. In the numerical analysis of modified Reynolds equation, the nonlinear simultaneous equations for the turbulent correction coefficients are greatly simplified to save computation time with a satisfactory accuracy under the assumption that the shear flow is superior to the pressure flow in the lubricant films. The numerical results of Sommerfeld number and attitude angle are compared with the experimental results to confirm the applicability of the modified Reynolds equation in the case of two types of bearings with different relative roughness heights. Good agreement was obtained between theoretical and experimental results.

On the Characteristics of Rectangular Bolted Flanged Connections With Gaskets Subjected to External Tensile Loads and Bending Moments

1994 ◽  
Vol 116 (2) ◽  
pp. 207-215 ◽  
Author(s):  
T. Morohoshi ◽  
T. Sawa
Keyword(s):  
Stress Distribution ◽  
Contact Stress ◽  
Maximum Stress ◽  
Tensile Load ◽  
Bending Moment ◽  
Theory Of Elasticity ◽  
Load Factor ◽  
Body Contact ◽  
Three Body ◽  
Contact Stress Distribution

This paper deals with the characteristics of a rectangular bolted connection of “T” shape with a gasket (filler plate), in which the flanges and a gasket (filler plate) are fastened with two bolts and nuts, and are then subjected to an external tensile load or a bending moment. The contact stress distribution which governs the sealing performance (clamping effect), the load factor (the relationship between an increment of axial bolt force and an external load), and the maximum stress produced in the bolt were analyzed by using a two-dimensional theory of elasticity as a three-body contact problem. Experiments were performed concerning the load factor and the maximum stress produced in the bolt. The analytical results are fairly consistent with experimental ones. The effects on the load factor and the contact stress distribution were examined for variation in Young’s modulus of different gaskets and the different distances between the bolt holes.

Numerical Simulation of Multi-Track Laser Cladding Process

2011 ◽  
Vol 399-401 ◽  
pp. 1802-1805 ◽  
Author(s):  
Jin Wu Kang ◽  
Tian You Huang ◽  
An Feng Zhang ◽  
Di Chen Li
Keyword(s):  
Numerical Simulation ◽  
Surface Roughness ◽  
Heat Source ◽  
Laser Cladding ◽  
Experimental Results ◽  
Laser Spot ◽  
Laser Cladding Process ◽  
Clad Layer ◽  
Overlap Ratio ◽  
Good Agreement

Multi-track laser cladding is necessary in the forming of parts. The overlap between neighbor tracks plays an important role, which determines the quality and surface smoothness of the clad layer. In this paper, numerical simulation of the multi-track laser cladding process is studied. The heat source of laser spot is applied by updating the profile of clad region and the location of the moving laser spot. The clad profile of overlapped track was obtained, from which the surface roughness was analyzed by the variation of overlap ratio. Meanwhile, experiments were carried out to evaluate the effect of overlap ratio. The simulated and the experimental results are in good agreement; both show that there is an optimal overlap ratio to achieve best surface roughness.

Analysis of the cutting ratio and investigating its influence on the workpiece’s diametrical error in ultrasonic-vibration assisted turning

2020 ◽  
pp. 095440542096817
Author(s):  
Hamid Soleimanimehr
Keyword(s):  
Surface Roughness ◽  
Ultrasonic Vibration ◽  
Vibration Analysis ◽  
Experimental Results ◽  
The Other ◽  
Turning Process ◽  
Flexible Workpiece ◽  
Machining Force ◽  
Increasing Trend ◽  
Good Agreement

Due to its numerous advantages such as reduction of machining force and surface roughness, ultrasonic-vibration assisted turning process has been extensively investigated. In the present paper, a new vibration analysis has been done and it has been shown that in the case of rigid workpiece or stable cutting ratio, negligible diametrical error is created by tool vibration in vibration turning which is not present in conventional turning. On the other part of the study, flexible workpiece has been considered and workpiece deformation has been investigated. It has been shown that in this case, the cutting ratio experiences an increasing trend from spindle to free end of one-end fixed workpiece. It has been also shown that the experimental results are in good agreement with analysis. Workpiece diametrical error in conventional turning is about twice in vibration turning.

Finite Element Analysis for Static Cushion Performance of (EPE) and Honeycomb Paperboard Combination

2018 ◽  
Vol 777 ◽  
pp. 457-461
Author(s):  
Ya Jun Wang ◽  
Xiao Ping Fan ◽  
Hong Xiang ◽  
Fang Ying Wu ◽  
Zhuo Jiang
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Stress Distribution ◽  
Yield Stress ◽  
Experimental Results ◽  
Deformation Characteristics ◽  
Element Analysis ◽  
Static Compression ◽  
Good Agreement

The solid modeling method for Expandable Polyethylene (EPE) and honeycomb paperboard combination structure was studied. The static compression of the structure was simulated by finite element method (FEM). The effect of the thickness of the EPE on the structure was analyzed, and the stress distribution and deformation characteristics were obtained. The results showed that the thickness of EPE had no significant effect on the yield stress of the structure, but the corresponding strain was increased with the increase of the thickness of EPE. The EPE could protect honeycomb paperboard from damage. The results of finite element analysis were in good agreement with the experimental results.

The Elastic Moduli of Heterogeneous Materials

1962 ◽  
Vol 29 (1) ◽  
pp. 143-150 ◽  
Author(s):  
Zvi Hashin
Keyword(s):  
Approximate Method ◽  
Elastic Moduli ◽  
Heterogeneous Materials ◽  
Theory Of Elasticity ◽  
Experimental Results ◽  
Two Phase ◽  
Concentric Spheres ◽  
Theoretical Results ◽  
Nonhomogeneous Materials ◽  
Good Agreement

Bounds and expressions for the elastic moduli of two or many phase nonhomogeneous materials are obtained by an approximate method based on the variational theorems of the theory of elasticity and on a concentric-spheres model. Theoretical results are in good agreement with experimental results for a two-phase alloy.

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