Studying Decreased Methods of Stress Concentration around Holes and Openings of Plate and Shell Structures’ Body
Journal Title: International Research Journal of Applied and Basic Sciences - Year 2013, Vol 5, Issue 8
Abstract
Phenomenon of stress concentration and creating it in shells is one of the scientifically and practically critical issues in structural and mechanical engineering. Submarines, vessels, wings and fuselages of airplanes, missiles and rockets, steam boilers and pressure tanks, pipes fittings in pipelines of fluids like gas, steam, water and wastewater are all examples of this phenomenon application in industry. Generally, creating an opening in a cylindrical shell or junction of two shells or even in plates, results in turbulence in stress field and creates stress concentration. The stress may be increased up to many times more than the stress created in body of shell structure (sometimes more than a hundred times) which is important from the standpoint of analysis and design. In this research, while reviewing previous studies and classifying the problems, we present the ruling equation in mixed form by partial derivative in fourth order; then, we present numerical solving approach with finite difference model as well as numerical solving approach with finite element model (with Ansys software). Then, we investigate trends of coefficient changes of stress concentration in plates and shells for different openings diameters and coefficient of curvatures (a dimensionless coefficient containing shell size including radius, thickness, and material as well as opening size and stress concentration depends on it) in single-hole or more mode and different types of openings such as circular, oval, square and rectangular influenced by different loadings to identify the effects of hole and opening on stress concentration phenomenon and its coefficient changes in plates and the shells. In addition, decrease of stress concentration is an important problem in theoretical, industrial, and applicable dimensions. Then, we offer some economical and practical solutions based on analysis and experimental tests. In these structures, one can decrease stress concentration using provisions like change of material, thickness (uniform and step form), using shell of different thickness (according to changes of stress diagram), using an amplification ring or loop around the opening and also inside of it. In this research, we investigate the effects of these parameters and show the results in diagrams and tables. Considering different methods for decrease of stress concentration (regarding limitations of laboratory and economic parameters), we introduce the optimum method for decreasing stress concentration of each shell with every type of openings or holes.
Authors and Affiliations
Mahdi Mirzagoltabarroshan| Sama technical and vocational training college, Islamic Azad University, Sari Branch, Sari, Iran, email: m.goltabar@yahoo.com
Keywords
Related Articles
- EP ID EP5990
- DOI -
- Views 314
- Downloads 8
Insight necessary against arrogant
No doubt the extraordinary requirements of the authorities and people in Islamic system are insight in broad vision at different aspects of religious, political, social, cultural and ….Today, safeguarding of values inher...
Study and comparison leadership styles of coachesand satisfaction of male and female athletes in the sport of karate and taekwondo
The aim of this study was to compare the leadership styles of coaching and satisfaction of individual athletes. The research employs descriptive-correlation method. The population of the study, all athletes participating...
Study of professional self - concept of nursing students of Shiraz University of medical science
Professional self-concept is the main key of professional concept. High level of self-concept is effective for enabling nurses, regarding to this point that most studies mostly put Emphasis on professional self-concept a...
Assessing an Ecological Production System for Rice Yield and Quality Improvement (Oryza sativa L. var. Hashemi)
Ecological systems which are types of organic or integrated farming, aim to improve quality and quantity at the same time. These systems can be used instead of conventional systems. A very important factor in success of...
Effects of seed priming on germination and emergence traits of two soybean cultivars under salinity stress
To evaluate effects of seed priming with potassium nitrate on germination and emergence traits of two soybean cultivars in salinity stress, two laboratorial and greenhouse experiments were carried out as a factorial expe...