Dissertation > Excellent graduate degree dissertation topics show

Stress Analysis of Pressure Pipeline with Large Diameter Opening Nozzle

Author: GuoXiaoQing
Tutor: ChenLiangYu
School: Northeastern University
Course: Mechanical Design and Theory
Keywords: Large opening rate Cylindrical shell Flush Nozzle Stress concentration factor ANSYS APDL MATLAB
CLC: TH49
Type: Master's thesis
Year: 2008
Downloads: 131
Quote: 1
Read: Download Dissertation

Abstract

Pressure pipe on the requirements of due process and structure is often necessary to offer a variety of open-cell structure, with a thin shell theory can only solve the opening rate ρ0 lt; 0.8's structure is still not opening rate ρ0 ≥ 0.8 large opening get the theoretical solution, generally rely on experimental studies, comparative analysis of design experience in design, safety and reliability can not be guaranteed, people gradually began to seek numerical methods for solving the approximate solution of the finite element method has become a solution to this problem the most important as a means. This paper studies the pressure pipe opening rate to take over the law of the intersecting parts of the local stress concentration, however, the pressure pipe to take over the research, the actual structure is more complex, it is impossible and it is not necessary to analyze in full accordance with the actual situation. Fully take into account the mechanical characteristics of the studied structure, binding characteristics and geometric symmetry, appropriate structure is selected as part of the calculation model. The practice of the subject: 1/4 of the cylindrical shell is selected only by the internal pressure, Flush Nozzle structure as a computational model. Based on a simplified model to determine the geometric parameters of the structure, the use of the APDL language a general-purpose computing model suitable for different sizes of hole nozzle construction. This project is the introduction of finite element modeling and analysis of parametric thinking, to avoid duplication of modeling and analysis, to simplify the design operation, improve the efficiency of finite element analysis. The use of elastic-plastic mechanics theory and finite element analysis using ANSYS software, a series of different thicknesses of the different opening rate than large opening rate cylindrical shell Flush Nozzle structure of a system of three-dimensional elastic finite element analysis, solving the shoulder point A stress concentration factor drawn into a table using MATLAB draw, including pressure opening rate of 0.8 ≤ ρ0 lt; between the stress concentration factor curve, to provide reference data for further study of the cylindrical shell to take over in the large opening. Based on a lot of three-dimensional finite element stress analysis of the structure of the cylindrical shell Flush Nozzle, opening ρ0 = 0.7 the finite element solution shell theoretical solution to compare, you can find the finite element solution closer to the actual law more conservative. Their stress concentration factor law, and summarized the empirical formula of a stress concentration factor using the method of least squares, the formula with three dimensionless parameters (d / d, t / T d / (?) DT) variable to the value calculated with the finite element solution according to the formula comparison found that the relative error of all data in the range of 0.2% to 5.92%, most of which less than 5% relative error only when opening rate ρ0 gt; 0.95 wall thickness ratio t / T = 8 the alerts, the relative error is greater than 5%. Therefore, this empirical formula to meet the accuracy requirements.

Related Dissertations

CLC: > Industrial Technology > Machinery and Instrument Industry > Gas compression and transportation machinery > Pressure vessel
© 2012 www.DissertationTopic.Net Mobile