Structural Design and Analysis of the New Mobile Refuge Chamber

Transcription

1 Key Engineering Materials Online: ISSN: , Vol. 584, pp doi: / Trans Tech Publications, Switzerland Structural Design and Analysis of the New Mobile Refuge Chamber CHANG Degong 1, a, SHAO Chen 1, b, LI Songmei 1, c and DU Minmin 1, d 1 College of Electromechanical Engineering, Qingdao University of Science and Technology, Qingdao , China a hyg867@163.com, b shaoshevchenko@126.com, c lisongmei1126@163.com, d duminmin1987@126.com Keywords: mobile refuge chamber, structure design, static analysis, ANSYS Abstract: At present, the mobile refuge chambers are mostly used square or circular structures. Based on these researches, a new chamber structure is presented in this paper, which is square and circular combined structure. The size and connection way are designed through the analysis of the working conditions and the requirements of the installation, transportation, maintenance and so on. Then the new structure is simplified to four kinds of cabin model, which can be analyzed by the ANSYS software. By the simulation analysis the reliability of the new structure is determined, which provides a theoretical basis for guiding the structural design of the mobile refuge chamber. Introduction The mobile refuge chamber is a kind of emergency refuge facilities underground, which can provides living conditions for people in distress, once under the mine happened disaster. The chamber as a main part must have the anti-pressure capacity, anti-explosion capacity, heat proof capacity and etc. The mobile refuge chamber is entirely square or circular structure at present. Square structure has a big available space, also is more convenient for personal activities. However, compared with the circular structure, its bearing capacity is weak under the same thickness conditions. The bearing capacity of circular structure is good, and the thickness requirement is smaller. But the available space is limited, which is inconvenient for personnel activities, and the requirements of internal placement and external fixation also have a certain difficulty. Therefore circular structure also needs more structural improvements. The mobile refuge chamber is mainly divided into air-lock, life supporting compartment and equipment compartment by the using function. According to the characteristics of each cabin and the pros and cons of square and round chamber, the new chamber structure is proposed, that is square and circular combined structure. In this paper, square and circular combined cabin is designed, then the static analysis and research is done by the ANSYS Workbench software. The overall design of chamber Analogy to the chamber produced by manufacturers on the market, transition and equipment compartments use square structure, which can help people walking in and out conveniently and fast, and equipment fixed easily. Crew compartment is adopted circular structure, to reduce the shock wave damage. Therefore, for ease of installation, transportation, replacement and maintenance of the chamber, sectional design is adopted, as shown in Fig.1. Taking into account the underground position, the internal arrangement, the insulation installation of the chamber, the height of the miner, and the other factors, the total length of the chamber is set to 11 meters and the width and height is 1.6 meters. Segmented chamber is divided into 11 sections, and each section is1 meter. Among them, three square chambers are placed at both ends of the chamber, and five circular chambers are placed in the middle. The dimensions of the chamber is finally decided as follows, the square chamber is 1.6m 1.6m 1.0m, the circular chamber is Ф1.6 m 1.0m. The material is Q345. All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of Trans Tech Publications, (ID: , Pennsylvania State University, University Park, USA-05/03/16,13:25:58)

2 176 Progress in Functional Manufacturing Technologies III Once the disaster is happened, the conditions are very inclement, always accompanied by explosions, landslides, permeable even induced other disasters. When the explosion occurred, the pressure of the air shock wave is very powerful. According to the technical requirements of refuge chamber, the chamber structure needs to fight against the explosive impact of 0.3MPa, so the requirements of strength and stiffness are relatively high. However, it can not simply rely on increasing the thickness of the wall to improve total strength and stiffness. For too large thickness of chamber will not only result in high quality of the refuge chamber and high economic costs, but also increase the difficulties of transport, lifting and assemble. Fig. 1 The chamber of square and circle combined structure Due to the different anti-pressure capacities of circular and square structures, the thickness of the chamber wall also is different. This paper the thickness of circular chamber wall is selected 12mm [1, 2], and the square is 20mm. Based on former research, stress concentration will exist in the structural transition zone. So it needs to weld ribs in the internal chamber wall, distributed vertical and horizontal. The design size of the rib is 30mm 70mm, and the material is Q345. When all components of the refuge chamber is sent to the underground, it is needed to assemble. Between the two chambers is connected by flange, which thickness is 17mm [3]. To satisfy the sealing requirements, sealing materials is embedded between the flanges, which specification for width thickness is 30mm 14mm, connected by bolts. Static analysis In this paper, the refuge chamber can be simplified into four models, which is square chamber with square flange at both ends, square chamber with one end closed and one end of the square flange, square chamber with one end of the square flange and one end of round flange, and circular chamber with round flange at both ends, which are shown in Fig.2. a) model 1 b) model 2 c) model 3 d) model 4 Fig. 2 Four kinds of chamber models

3 Key Engineering Materials Vol This four chamber models are imported into the finite element analysis simulation software-ansys Workbench to do static analysis. Then meshing the model adopted 10-node tetrahedral element. The fixed constraints are imposed on the underside of the chamber, and the 0.3MPa uniform load is applied on the surface. The static structural analysis results of the models are shown in Fig.3. a) Stress and strain diagrams of model 1 b) Stress and strain diagrams of model 2 c) Stress and strain diagrams of model 3 d) Stress and strain diagrams of model 4 Fig. 3 Static structural analysis results of the models The strain pictures of four models show that the maximum deformation of model 1 appears on the central portion of the both sides of the chamber, and the maximum deformation area is relatively large. The maximum deformation area of model 2 and 3 appears on central portion of the both sides close to the square flange, the area is small but the maximum deformation is larger. The maximum

4 178 Progress in Functional Manufacturing Technologies III deformation area of model 4 appears on the center of the circular chamber, but the maximum deformation is small which has little impact on the chamber. The stress pictures of four models show that the maximum stress appears on the corner, where is the area of stress concentration. However, according to the basic theory of mechanics, in the analysis the model will produce the phenomenon of stress singularity due to the computation time and the influence of the software itself[4]. Therefore, the stress occurring on the sharp corners or boundaries is incorrect, which can be ignored. Table 1 The data output of static structural analysis of each model Model 1 Model 2 Model 3 Model 4 Deformation /mm Equivalent stress /MPa Max Min Max Min Table 1 is obtained by Fig.3 which can be more intuitive to compare the maximum strain and stress values of each model. It can be seen that the maximum deformation and equivalent stress of model 2 and 3 is basically same, but the compression capability is weak compared with other models. Therefore, the combination of square and circular structures and the end of the square chamber are the weakest sections, where can be placed equipment with high compression capability. Compared with the other three models, the maximum strain and stress of model 4 is the smallest, and the structure has strongest compressive strength, which is satisfied with the previous design requirements and ensure the safety of the person. For the entire chamber, the maximum deformation appears on the model 3, is about 1.3mm. And the maximum stress also appears on the model 3, is approximately 215MPa, which is within the allowable range of Q345. It can be seen that the static analysis of the refuge chamber design meets the requirements. Summary The stress-strain values of the simplified models are obtained by the ANSYS Workbench static analysis. The results verify that the new design meet the requirements of the refuge chamber, and reflect the reasonable and superiority of the structure. The study provides a reference for the arrangements of subsequent refuge chambers, and also lay a solid foundation for the further research of anti-explosion, high temperature resistant, air tightness and other performances. References [1] Shou Binan, Yang Guoyi, Xu Feng. GB The Standard Definition of Pressure Vessel[M]. Beijing: Xinhua Press, [2] Standardization Technical Committee of National Pressure Vessel, JB , Steel Pressure Vessel- Analysis and Design Standards. [3] National Administration of Machinery Industry, State Petroleum and Chemical Industry, JB/T4700~ , Pressure Vessel Flange. [4] Liu Hongwen, Mechanics of Materials I, version 4 [M]. Beijing: Higher Education Press, 2004.

5 Progress in Functional Manufacturing Technologies III / Structural Design and Analysis of the New Mobile Refuge Chamber /