There are many technical discussions between global manufacturing and development companies competing to design a lightweight container to satisfy the requirements of shipping and airline companies. In this study, a methodology for a minimum weight optimization for honeycomb core sandwich panels with composite face sheets is presented, which can be primarily used for manufacturing of the walls, floor and roof of containers. The honeycomb sandwich panels consisted of symmetric composite face sheets the face sheets consisted of E-glass / epoxy fiber-reinforced plastic. The lay-up of the fibers of the face sheets was limited to sets of plies having orientation angles of 0 and 90. The new lightweight containers provide considerable savings in weight and thus reduce fuel consumption or increase aircraft turnover compared to conventional containers (see Fig. 1). According to the International Air Transport Association (IATA) calculations, the weight of fuel required to carry 1kg additional weight per hour is 0.04 Kg. The weight of the sandwich structure panels considered is the objective function subject to constraints needed based on the stiffness, face sheets failure, skin wrinkling and core shear. MATHLAB software was used to obtain theoretical results and compare them with numerical and experimental results. The strategies of composite sandwich structures depended on classical lamination theory. The program calculates the ply failures automatically by using the Tsai–Hill failure criterion for every combination of face sheet and core thicknesses.
{"title":"Structural Optimization of a Sandwich Panels Design for Minimum Weight Shipping and Airplane Containers","authors":"A. Al-Fatlawi, K. Jármai, G. Kovács","doi":"10.26649/musci.2019.036","DOIUrl":"https://doi.org/10.26649/musci.2019.036","url":null,"abstract":"There are many technical discussions between global manufacturing and development companies competing to design a lightweight container to satisfy the requirements of shipping and airline companies. In this study, a methodology for a minimum weight optimization for honeycomb core sandwich panels with composite face sheets is presented, which can be primarily used for manufacturing of the walls, floor and roof of containers. The honeycomb sandwich panels consisted of symmetric composite face sheets the face sheets consisted of E-glass / epoxy fiber-reinforced plastic. The lay-up of the fibers of the face sheets was limited to sets of plies having orientation angles of 0 and 90. The new lightweight containers provide considerable savings in weight and thus reduce fuel consumption or increase aircraft turnover compared to conventional containers (see Fig. 1). According to the International Air Transport Association (IATA) calculations, the weight of fuel required to carry 1kg additional weight per hour is 0.04 Kg. The weight of the sandwich structure panels considered is the objective function subject to constraints needed based on the stiffness, face sheets failure, skin wrinkling and core shear. MATHLAB software was used to obtain theoretical results and compare them with numerical and experimental results. The strategies of composite sandwich structures depended on classical lamination theory. The program calculates the ply failures automatically by using the Tsai–Hill failure criterion for every combination of face sheet and core thicknesses.","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128445224","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The Effect of Optimization on the Design of Steel Structures","authors":"K. Jármai, S. Kmeť","doi":"10.26649/musci.2019.043","DOIUrl":"https://doi.org/10.26649/musci.2019.043","url":null,"abstract":"","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115228411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Phenomenological Modeling of Gas Explosion in Closed Vessel","authors":"Viktória Mikáczó, G. Szepesi","doi":"10.26649/musci.2019.047","DOIUrl":"https://doi.org/10.26649/musci.2019.047","url":null,"abstract":"","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"109 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121430057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stress corrosion cracking (SCC) even nowadays is the cause of significant service failures, it can occur in almost any type of components of the chemical industry such as steam generator tubes, pressurizer instrument penetrations and heater sleeves, control rod drive mechanism (CRDM) nozzles, heat exchangers [1]-[6]. One of the most recent major accident happened in 2009, where a 50-foot-tall highpressure vessel ruptured, resulting in one fatality and one injury of the public. Based on the review of the National Institute of Standards and Technology the failure was caused by the combination of stress corrosion cracking and a reduction in material toughness during service [6]. In case of existing nuclear power plants the stress corrosion cracking counts as one of the important ageing degradations. For stress corrosion to occur three indispensable factors have to be present, which are the tensile stress, the environment and the susceptible material. If changes are made in any of these factors then the susceptibility to SCC often can be eliminated or reduced. The tensile stress can originate from residual stresses, operational loadings, the structural and metallurgical factors includes the degree of grain size, thermal treatment, cold work, and finally the environment factors are resulted from the water chemistry, the operating temperature [1]. However this type of failure is sudden and difficult to predict and also material properties may change with time or due to material processing. Therefore the right way of prediction and modelling of SCC is still a vital research area. In this article the different type of SCC mechanisms are presented, the ones used in the nuclear industry in more details.
{"title":"Mechanisms of Stress Corrosion Cracking","authors":"Bernadett Spisák, S. Szávai","doi":"10.26649/musci.2019.052","DOIUrl":"https://doi.org/10.26649/musci.2019.052","url":null,"abstract":"Stress corrosion cracking (SCC) even nowadays is the cause of significant service failures, it can occur in almost any type of components of the chemical industry such as steam generator tubes, pressurizer instrument penetrations and heater sleeves, control rod drive mechanism (CRDM) nozzles, heat exchangers [1]-[6]. One of the most recent major accident happened in 2009, where a 50-foot-tall highpressure vessel ruptured, resulting in one fatality and one injury of the public. Based on the review of the National Institute of Standards and Technology the failure was caused by the combination of stress corrosion cracking and a reduction in material toughness during service [6]. In case of existing nuclear power plants the stress corrosion cracking counts as one of the important ageing degradations. For stress corrosion to occur three indispensable factors have to be present, which are the tensile stress, the environment and the susceptible material. If changes are made in any of these factors then the susceptibility to SCC often can be eliminated or reduced. The tensile stress can originate from residual stresses, operational loadings, the structural and metallurgical factors includes the degree of grain size, thermal treatment, cold work, and finally the environment factors are resulted from the water chemistry, the operating temperature [1]. However this type of failure is sudden and difficult to predict and also material properties may change with time or due to material processing. Therefore the right way of prediction and modelling of SCC is still a vital research area. In this article the different type of SCC mechanisms are presented, the ones used in the nuclear industry in more details.","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125694192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fogyatékosság és az információs társadalom - jogi aspektusok","authors":"Erika Csemáné Váradi","doi":"10.26649/musci.2019.102","DOIUrl":"https://doi.org/10.26649/musci.2019.102","url":null,"abstract":"","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129445400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The world of the workers is changing. In Europe, the national social protection systems have been developed basically to protect the workers in standard employment.[2] But, this protecting system based on the old dogmatic framework of the labour law can’t handle those persons, who are the so called employee-like persons, or globally, the new forms of employment. “People in non-standard employment have always been in a more insecure and precarious situation regarding access to schemes and receipt of insurance-based benefits.”[3] The non-standard employment is a big category, it includes a lot of relationships, such as selfemployment, freelance work and temporary agency work. These are a really high part of the workers in some sectors, such as construction, tourism, media, entertainment, etc.[4] The employee-like persons, which also is a form of nonstandard work, is a category of the new working structures, because these workers are working in similar conditions to the traditional employees, but are only in economic dependence, not in personal dependence. The lack of personal dependence occurs in a lot of creative professions, but also by those relationships, that are based on the modern techniques, for example in the IT-sector. This difference from the traditional employee-status means, that these workers are not protected by the labour law. They aren’t the part of the employee-definition in the traditional labour law, so they can’t use the rights of the labour law, despite the fact, that they are economically dependent from their one, or small number of costumer. In order to summarise, what does this category “employee-like person” mean, we have to list the main factors, that are characterising these people: they are working under a contract, which is not a labour contract, but mainly an engagement contract, special-order contract, or mandate; they have to work personally, they are not
{"title":"Reflections on the Employee-Like Persons and on Their (Non-)Regulation in Hungary","authors":"B. Szekeres","doi":"10.26649/musci.2019.064","DOIUrl":"https://doi.org/10.26649/musci.2019.064","url":null,"abstract":"The world of the workers is changing. In Europe, the national social protection systems have been developed basically to protect the workers in standard employment.[2] But, this protecting system based on the old dogmatic framework of the labour law can’t handle those persons, who are the so called employee-like persons, or globally, the new forms of employment. “People in non-standard employment have always been in a more insecure and precarious situation regarding access to schemes and receipt of insurance-based benefits.”[3] The non-standard employment is a big category, it includes a lot of relationships, such as selfemployment, freelance work and temporary agency work. These are a really high part of the workers in some sectors, such as construction, tourism, media, entertainment, etc.[4] The employee-like persons, which also is a form of nonstandard work, is a category of the new working structures, because these workers are working in similar conditions to the traditional employees, but are only in economic dependence, not in personal dependence. The lack of personal dependence occurs in a lot of creative professions, but also by those relationships, that are based on the modern techniques, for example in the IT-sector. This difference from the traditional employee-status means, that these workers are not protected by the labour law. They aren’t the part of the employee-definition in the traditional labour law, so they can’t use the rights of the labour law, despite the fact, that they are economically dependent from their one, or small number of costumer. In order to summarise, what does this category “employee-like person” mean, we have to list the main factors, that are characterising these people: they are working under a contract, which is not a labour contract, but mainly an engagement contract, special-order contract, or mandate; they have to work personally, they are not","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130851035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The material quality, the deformation rate, the temperature and the stress state influence mechanical behaviour and properties of different materials. Due to this great variety of the influencing factors we do not have one general model describing the behaviour of materials; then again we have to use a great number of material constants in order to characterize the material properties. The exponents of the Manson-Coffin, the Basquin and the Paris-Erdogan laws were applied for the verification of the connection among the fatigue fracture types. Own measured values and test results that can be found in the literature were used for the illustration of the connections. “Fracture surface”-s can be determined for characterizing the behaviour of different steel and aluminium grades and their welded joints, under cyclic loading conditions. It can be concluded that “fracture surface”-s are suitable for describing the fracture behaviour and the conversion of different fracture parameters of different steels and aluminium alloys.
{"title":"Connection Among the Parameters of the Manson-Coffin, the Basquin and the Paris-Erdogan Equations","authors":"H. Mobark, J. Lukács","doi":"10.26649/musci.2019.041","DOIUrl":"https://doi.org/10.26649/musci.2019.041","url":null,"abstract":"The material quality, the deformation rate, the temperature and the stress state influence mechanical behaviour and properties of different materials. Due to this great variety of the influencing factors we do not have one general model describing the behaviour of materials; then again we have to use a great number of material constants in order to characterize the material properties. The exponents of the Manson-Coffin, the Basquin and the Paris-Erdogan laws were applied for the verification of the connection among the fatigue fracture types. Own measured values and test results that can be found in the literature were used for the illustration of the connections. “Fracture surface”-s can be determined for characterizing the behaviour of different steel and aluminium grades and their welded joints, under cyclic loading conditions. It can be concluded that “fracture surface”-s are suitable for describing the fracture behaviour and the conversion of different fracture parameters of different steels and aluminium alloys.","PeriodicalId":340250,"journal":{"name":"MultiScience - XXXIII. microCAD International Multidisciplinary Scientific Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122630919","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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