ASME SECCION VIII DIV. 1 ED 2015 CALCULOS MECANICO (original) (raw)

A Proposed Method for Finding Stress and Allowable Pressure in Cylinders with Radial Nozzles

A simple technique is presented for calculating the local primary stress from internal pressure in nozzle openings. Nozzle internal projections, reinforcing pads and fillet welds are considered for nozzles on cylinders. The technique uses beam on elastic foundation theory and extends the work of W. L. McBride and W. S. Jacobs . A study comparing the proposed method with ASME Section VIII, Division 1 [2] rules and finite element analysis (FEA) is presented for the range of geometries listed in WRC-Bulletin 335. The proposed method predicts a maximum local primary stress that is in good agreement with FEA and burst test data.

A Textbook of Machine Design Pressure Vessels

of the shell is greater than 1/10 of the diameter of the shell, then it is said to be a thick shell. Thin shells are used in boilers, tanks and pipes, whereas thick shells are used in high pressure cylinders, tanks, gun barrels etc.

Pressure limits of thick-walled cylinders

2009

The effect of autofrettage on thick-walled cylinders, operating under high internal pressure, has become a significant area of development, both in research and practice. In optimal design of thick-walled cylinders, there are two main objectives to be achieved: increasing its strength-weight ratio and extending its fatigue life. This can be achieved by generating a residual stress field in the cylinder wall prior to use. Both analytical and numerical techniques have been used for the investigation of the effects of residual stresses on the load-carrying capacity. The scope of the current paper includes application of ABAQUS finite element code to the direct problem of finding thick-walled cylinder autofrettage solutions. The results reveal three scenarios in the design of thick-walled cylinders. For maximum load carrying capacity, non-autofrettage is suitable when, in service, the whole wall thickness will be yielded. Full autofrettage is suitable when, during subsequent operation, ...

IJERT-Study of different type reinforcement in cylindrical pressure vessel

International Journal of Engineering Research and Technology (IJERT), 2013

https://www.ijert.org/study-of-different-type-reinforcement-in-cylindrical-pressure-vessel https://www.ijert.org/research/study-of-different-type-reinforcement-in-cylindrical-pressure-vessel-IJERTV2IS100894.pdf Due to practical requirements, pressure vessels are often equipped with openings of various shapes, sizes and positions. Vessels have openings to accommodate manholes, handholds, and nozzles. Openings vary in size from small drain nozzles to full vessel size openings with body flanges. The openings cannot be avoided because of various piping or measuring gauge attachments. To avoid failure in the opening area, compensation or reinforcement is required. The additional material is deemed effective in carrying the higher loads. On most vessels, it is provided on the outside of the vessel. In some vessels, the reinforcement appears inside, while in others both inside and outside regions are reinforced. The main purpose of this paper is to perform a stress analysis on thin-walled pressure vessels with different type of the reinforcement and optimize the suitable reinforcement for opening using finite element analysis software namely, ANSYS. General applications of Thin-walled cylinders are commonly used as structural members (e.g., hollow structural sections), piping systems, members of offshore platforms, cooling towers, aircraft fuselages, naval halls of submarines, high pressure reactor vessels used in metallurgical operations, process plants etc.

Stress Analysis of Different Reinforcement PAD for Nozzle Opening in Pressure Vessel

This paper presents the comparative stress analysis of pressure vessels which are subjected to internal fluid pressure. The area of shell wall near nozzle opening is seriously affected due to stress concentration which may cause the failure of pressure vessels. To minimize the stress concentration conventionally circular reinforcement pad is provided for shell wall. Depending upon the usage of pressure vessels, too much care is required in analysis of pressure vessels. Here an attempt is made to carryout comparative stress analysis. A pressure vessel having 7700mm internal diameter and 32mm thickness is selected for analysis. Nozzle diameters are taken 600,700,800,900,1000,1100 and 1200mm. CREO PARAMETRIC 3.0 is used to create geometry and ANSYS Workbench has been used for stress analysis. Here analysis is carried out for different models i.e. without reinforcement pad i.e. opening only and with circular as well as elliptical reinforcement pad. Further analysis is carried out for two models having maximum effect of reinforcement pad. A detailed comparative stress analysis has been carried out which shows that if elliptical reinforcement pad is used in place of circular reinforcement pad the saving in area required is about 30% to 50% which eventually reduce the cost of fabrication of pressure vessels.