Proposal of Rationalized Assessment Procedure for Buckling of Thin-Walled Cylindrical Tanks

Author(s):  
Hitohsi Kaguchi ◽  
Koji Hamada ◽  
Akihisa Sugiyama ◽  
Hideyuki Morita ◽  
Koji Setta ◽  
...  
Author(s):  
Christian Protz ◽  
Uwe Zencker ◽  
Robert Liebich

Alternatively to experimental drop tests, the mechanical safety analyses of containers for final disposal of radioactive waste with negligible heat generation in the German Konrad repository may be carried out by numerical simulations within the safety assessment procedure. In the past, safety assessments for thin-walled steel sheet containers have been done exclusively by prototype tests and unfavorable drop scenarios were determined by engineering judgment. So far, reliable numerical simulations do not exist. Therefore, a research project was started to develop numerical simulation approaches for drop test analyses and to determine existing safety margins. Comparisons of experimental and numerical results confirm that the Finite Element (FE) model represents the general mechanical behavior of the steel sheet container sufficiently. Simulations have been used to determine an unfavorable drop scenario resulting in large deformation and damage. This paper presents the investigations carried out as well as the further development of the FE model in terms of damage mechanics.


2010 ◽  
pp. 47-52
Author(s):  
Caitríona de Paor

Thin-walled structures, also known as shells, combine light weight with high strength and are used in a diverse range of fields including aerospace engineering, civil engineering and chemical engineering. Common applications of these shells include oil and gas storage tanks, powder or liquid storage tanks in pharmaceutical plants as well as airplane frames and ship bodies. Although these thin-walled shells have a wide variety of uses, this research is motivated by storage tank collapse in the process industry. Thin-walled cylindrical tanks common in the food and biotechnology sectors are prone to buckling (or inward collapse) due to accidentally induced internal vacuum. During the sterilisation process, steam can condense, causing a reduction in volume. This results in an equivalent increase in external pressure, triggering collapse, or buckling of the tank. Such a collapse, if it occurs, tends to be catastrophic resulting in the complete destruction of the vessel (see Fig.1). Notwithstanding ...


2007 ◽  
Vol 120 ◽  
pp. 199-206
Author(s):  
Hitohsi Kaguchi ◽  
Koji Hamada ◽  
Akihisa Sugiyama ◽  
Hideyuki Morita ◽  
Koji Setta ◽  
...  

As for thin walled cylindrical liquid storage tanks in nuclear power plants, the current elastic design guideline against seismic loading might result in too conservative component design. Therefore, it is thought possible to make the design procedure more reasonable by taking dynamic response reduction into account. Experiments using scaled models as well as numerical analyses were carried out, and seismic behavior of thin walled cylindrical liquid storage tanks was simulated to investigate energy absorption capacity and seismic resistance of those tanks. Based on the test and analysis results, assessment procedure for buckling considering post-buckling behavior has been proposed.


2010 ◽  
Vol 16 (2) ◽  
pp. 209-215 ◽  
Author(s):  
Konstantin Rasiulis ◽  
Kęstutis Gurkšnys

Major repair or regular inspection of the large capacity thin‐walled tankages is very expensive. Steel cylindrical tanks are an individual case of the thin‐walled tankages. The common calculation of the tanks by analytical and numerical methods is not difficult. Strengthening the places, where a perfect calculated form is disturbed, that is, at the spots of in‐cuts, hatches, defects etc. is a responsible part of the design of such constructions. The problems of prevention of defects during the operation period and repairs, as well as possibility to assure quickly the safety of defective places of the constructions are more important than the common calculations. The main objective of the presented investigations is to identify stress/strain state of the wall tank with local imperfections from the ideal cylindrical surface, taking into account the membrane theory of the shells by using the finite element's method. Santrauka Didelio tūrio statiniu remontai arba net profilaktines apžiūros yra gana brangūs procesai. Metalines cilindrines talpyklos priskiriamos prie atskiros tūriniu plonasieniu konstrukciju grupes. Talpyklu reguliariu konstrukciju analitiniai ar skaitiniai skaičiavimai nera sudetingi. Bet tokiu vietu, kaip konstrukciju jungčiu bei technologines irangos prijungimo projektavi‐mas ar konstrukciju defektu analize yra gerokai svarbesne projektavimo dalis. Defektu prevencija naudojant talpyklas, taip pat defektuotu vietu sustiprinimas yra svarbesnis nei bendrieji talpyklu skaičiavimai. Šio darbo tikslas ‐ nustatyti realaus objekto cilindrines talpyklos sieneles su geometrinemis lokaliomis nuokrypomis itempiu ir deformaciju būvi pagal memb‐ranine kevalu skaičiavimo teorija, taikant baigtiniu elementu metoda.


1998 ◽  
Vol 31 (1-3) ◽  
pp. 203-220 ◽  
Author(s):  
H. Schmidt ◽  
B. Binder ◽  
H. Lange

2001 ◽  
Vol 17 (1) ◽  
pp. 25-35 ◽  
Author(s):  
G. Leonard Burns ◽  
James A. Walsh ◽  
David R. Patterson ◽  
Carol S. Holte ◽  
Rita Sommers-Flanagan ◽  
...  

Summary: Rating scales are commonly used to measure the symptoms of attention deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), and conduct disorder (CD). While these scales have positive psychometric properties, the scales share a potential weakness - the use of vague or subjective rating procedures to measure symptom occurrence (e. g., never, occasionally, often, and very often). Rating procedures based on frequency counts for a specific time interval (e. g., never, once, twice, once per month, once per week, once per day, more than once per day) are less subjective and provide a conceptually better assessment procedure for these symptoms. Such a frequency count procedure was used to obtain parent ratings on the ADHD, ODD, and CD symptoms in a normative (nonclinical) sample of 3,500 children and adolescents. Although the current study does not provide a direct comparison of the two types of rating procedures, the results suggest that the frequency count procedure provides a potentially more useful way to measure these symptoms. The implications of the results are noted for the construction of rating scales to measure the ADHD, ODD, and CD symptoms.


2009 ◽  
Author(s):  
Patricia M. Power ◽  
Dermot Barnes-Holmes ◽  
Yvonne Barnes-Holmes ◽  
Ian T. Stewart

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