Mechanical Behavior of Inner Sleeve for Hydraulic Safety Coupling Subject to Bending and Oil Pressure Load

ABSTRACT

The objective of this paper is to investigate the mechanical behaviour of the inner sleeve for a new type of hydraulic safety coupling. Based on the theory of space axis symmetric and hollow cylinder problem in elasticity, a comprehensive formulation of a mathematical model is presented. The model takes both the non-bending theory and the bending theory into account. And then the effects of three kinds of boundary conditions on deformation and stress fields in the middle section of the inner sleeve are analysed. The experimental data for a particular model using the screw regulation way are compared with the calculated data. It is shown that any form of constraints on either end of the inner sleeve can ultimately lead to the increase of deformation. When one end is fixed and the other end is free, the maximum deformation occurs at the adjacent zone of the middle cross section of the inner sleeve. The maximum stress under the boundary condition of both ends is simply supported is larger than that under the other two boundary conditions. The model developed in this research will potentially form the framework for a complete model in further research.

KEYWORDS:

• Hydraulic safety coupling
• inner sleeve
• cylindrical shell
• mechanical deformation
• stress calculation

Nomenclature

$u_r$, $u_{\theta }$	=	Displacement component in the radial and tangential direction, respectively
${\gamma }_{r\theta }$, ${\gamma }_{\theta z}$, ${\gamma }_{zr}$	=	Shear strain
${\epsilon }_r$, ${\epsilon }_{\theta }$, ${\epsilon }_z$	=	Normal strain component in the radial, tangential and axial direction, respectively
${\sigma }_r$, ${\sigma }_{\theta }$, ${\sigma }_z$	=	Radial, tangential and axial normal stress, respectively
${\tau }_{zr}$	=	Tangential stress in the radial direction
E	=	Elasticity modulus
$\mu$	=	Poisson’s ratio
N1, N2	=	Tensile force that acting on the cross section when $\alpha$ and $\beta$ remain unchanged, respectively
S1, S2	=	Tensile force that acting on the cross section when $\alpha$ and $\beta$ remain unchanged, respectively
M1, M2	=	Bending moment that acting on the cross section when $\alpha$ and $\beta$ remain unchanged, respectively
M12, M21	=	Torsional moment that acting on the cross section when $\alpha$ and $\beta$ remain unchanged, respectively
Q1, Q2	=	Transverse shear that acting on the cross section when $\alpha$ and $\beta$ remain unchanged, respectively
$q_1$, $q_2$, $q_3$	=	Three components of load along the directions of $\alpha$, $\beta$ and $\gamma$, respectively
$u$, $v$, $w$	=	Three components of displacement along the directions of $\alpha$, $\beta$ and $\gamma$, respectively

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the China Postdoctoral Science Foundation [2018M632199];National Natural Science Foundation of China [51805464];Scientific Research Foundation of Advanced Professional of Yancheng Institute of Technology [XJ201701].

Notes on contributors

Jianzhong Cui

Jianzhong Cui received his Bachelor' s degree in mechanical engineering from Yangzhou University in 2007 and earned his PhD degree from Jiangsu University in 2015. Since 2016, he has engaged in teaching and research in the Research Center of Mould Intelligent Manufacturing Technology of Yancheng Institute of Technology, China. He has also been a postdoctoral researcher in Southeast University since 2017. His main areas of interest are Fluid Machinery Design, Computational Fluid Dynamics (CFD), Tribology and Fluid Transmission.

Xueya Zhao

Xueya Zhao received her Master's degree in mechanical engineering from Nanjing Institute of Technology in June, 2016. Her current principle research activities are the control and design of mechanical and electrical products.

Benguo Zhang

Benguo Zhang received his PhD degree in mechanical engineering from Yanshan University in 2012. He is currently working as an assistant professor in the Research Center of Mould Intelligent Manufacturing Technology of Yancheng Institute of Technology, China.  He is currently working in Engineering Design and Numerical Analysis of  Metal Forming.