<p>This report investigates the feasibility and accuracy of determining fastener flexibility with 3D FE and representing fasteners in FE load distribution models with simple elements such as springs or beams. A detailed study of 3D models compared to experimental data is followed by a parametric study of different shell modelling techniques. These are evaluated and compared with industry semi-empirical equations.</p><p>The evaluated 3D models were found to match the experimental values with good precision. Simulations based on these types of 3D models may replace experimental tests. Two different modelling techniques were also evaluated for use in load distribution models. Both were verified to work very well with representing fastener installations in lap-joints using the ABAQUS/Standard solver. Further improvement of one of the models was made through a modification scale factor. Finally, the same modelling technique was verified using the NASTRAN solver.</p><p>To summarize, it is concluded that:</p><p>• Detailed 3D-models with material properties defined from stress-strain curves correspond well to experiments and simulations may replace actual flexibility tests.</p><p>• At mid-surface modelling of the connecting parts, beam elements with a circular cross section as a connector between shell elements is an easy and accurate modelling technique, with the only data input of bolt material and dimension.</p><p>• Using connector elements is accurate only if the connecting parts are modelled in the same plane, i.e. with no offset. Secondary bending due to offset should only be accounted for once and only once throughout the analysis, and it is already included in the flexibility input.</p>

This report investigates the feasibility and accuracy of determining fastener flexibility with 3D FE and representing fasteners in FE load distribution models with simple elements such as springs or beams. A detailed study of 3D models compared to experimental data is followed by a parametric study of different shell modelling techniques. These are evaluated and compared with industry semi-empirical equations. The evaluated 3D models were found to match the experimental values with good precision. Simulations based on these types of 3D models may replace experimental tests. Two different modelling techniques were also evaluated for use in load distribution models. Both were verified to work very well with representing fastener installations in lap-joints using the ABAQUS/Standard solver. Further improvement of one of the models was made through a modification scale factor. Finally, the same modelling technique was verified using the NASTRAN solver. To summarize, it is concluded that: • Detailed 3D-models with material properties defined from stress-strain curves correspond well to experiments and simulations may replace actual flexibility tests. • At mid-surface modelling of the connecting parts, beam elements with a circular cross section as a connector between shell elements is an easy and accurate modelling technique, with the only data input of bolt material and dimension. • Using connector elements is accurate only if the connecting parts are modelled in the same plane, i.e. with no offset. Secondary bending due to offset should only be accounted for once and only once throughout the analysis, and it is already included in the flexibility input.

Devido à evolução e à crescente complexidade dos sistemas computacionais, grandes mudanças ocorreram na área de gerenciamento de redes. Os modelos tradicionais centralizados se mostraram limitados, e novos modelos de gerenciamento de redes estão sendo propostos e investigados. Neste cenário, modelos de comunicação P2P permitem a construção de ambientes dinâmicos e versáteis capazes de resolver problemas de diferentes áreas da computação, entre elas o gerenciamento de redes. O modelo P2P torna-se atrativo porque se encaixa perfeitamente no gerenciamento de redes distribuído atualmente solicitado. A partir da proposta de gerenciamento de redes usando P2P e da apresentação de um novo modelo conceitual usando essa nova perspectiva, foi desenvolvido um projeto de arquiteturas para gerenciamento baseadas em P2P, focando-se em entidades tais como peers de gerenciamento Top-Level (TLM) e Mid-Level (MLM). A fim de efetivamente concretizar o gerenciamento baseado em P2P, foram introduzidas definições de blocos básicos para sistemas de gerenciamento baseados em P2P. A integração desses blocos básicos com soluções tradicionais de gerenciamento, tal como a estrutura SNMP, também foi apresentada. Um dos conceitos centrais da arquitetura apresentada são os Serviços de Gerenciamento, que definem as tarefas básicas de gerenciamento do sistema, e foram inspirados nos conceitos de Web Services e na concepção de serviços das Arquiteturas Orientadas a Serviço (SOA). Para a avaliação desse novo modelo de gerenciamento de redes e da arquitetura associada, surgiu a necessidade do desenvolvimento de um protótipo do sistema, com o intuito de servir como uma plataforma para desenvolvimento e implantação de Serviços de Gerenciamento. Esse protótipo é usado para avaliação e análise de testes e resultados associados. Para preservar as características de disponibilidade e escalabilidade que são inerentes dos sistemas P2P, definiu-se que os Serviços de Gerenciamento devem ser disponibilizados por Grupos de MLMs, organizados de forma a fazer a distribuição de tarefas de gerenciamento entre si. Diversos modelos de distribuição de carga foram investigados, foram realizadas avaliações e gráficos comparativos, e foram estabelecidas diretrizes sobre quando e como deve ser aplicado cada modelo, de modo a alcançar sempre o melhor rendimento e a maximização do aproveitamento dos recursos disponíveis ao sistema. A avaliação realizada consistiu na execução de diversas requisições com diferentes números de MLMs usando diferentes algoritmos de distribuição de carga, e na comparação entre a vazão, os tempos de resposta e o tráfego de rede gerados pelos diferentes casos de uso. A implementação desenvolvida neste trabalho demonstrou ser promissora, apresentando resultados bastante satisfatórios com relação aos parâmetros avaliados. / Due to the increasing complexity of computer systems, deep changes have occurred in network management in the past few years. Traditional centralized models have been proved limited, and new network management models are being proposed and investigated. In this scenery, P2P communication models allow for the creation of dynamic and versatile environments, able to solve problems in various computational areas, one of them being network management. The P2P model fits perfectly in the current demands of distributed network management. Starting from the proposed P2P-based network management model, a new P2P-based network management architecture has been developed, focusing on entities like Top-Level (TLM) and Mid-Level (MLM) management peers. With the purpose of making the P2P-based network management real, new building blocks for P2P-based network management systems have been defined. In the present work, an integration of these new building blocks with traditional network management solutions - like SNMP - is presented. One of the main concepts of the proposed architecture is on Management Services, inspired by Web Services and in the service definition of Service Oriented Architectures (SOA). To evaluate this new network management model and its associated architecture, it was necessary to develop a prototype system to be used as platform for development and deployment of Management Services. This prototype was used for evaluation, testing and result analysis. To hold the characteristics of availability and scalability that are inherent to the P2P systems, the Management Services had to be served by MLM groups, organized in a way to distribute the management tasks between them. Several load distribution models were investigated, with evaluation and comparative graphics fulfilled, and some guidelines were established as to when and how each model should be applied to reach the best performance and the maximization of the computational resources available to the system. The evaluation consisted in the execution of several requests in groups with distinct MLM numbers and using distinct load distribution algorithms. Then, the response time and network traffic generated by use cases were compared. We then showed that the developed implementation of our proposal is promising, and presents good results in relation with the evaluated parameters.

Devido à evolução e à crescente complexidade dos sistemas computacionais, grandes mudanças ocorreram na área de gerenciamento de redes. Os modelos tradicionais centralizados se mostraram limitados, e novos modelos de gerenciamento de redes estão sendo propostos e investigados. Neste cenário, modelos de comunicação P2P permitem a construção de ambientes dinâmicos e versáteis capazes de resolver problemas de diferentes áreas da computação, entre elas o gerenciamento de redes. O modelo P2P torna-se atrativo porque se encaixa perfeitamente no gerenciamento de redes distribuído atualmente solicitado. A partir da proposta de gerenciamento de redes usando P2P e da apresentação de um novo modelo conceitual usando essa nova perspectiva, foi desenvolvido um projeto de arquiteturas para gerenciamento baseadas em P2P, focando-se em entidades tais como peers de gerenciamento Top-Level (TLM) e Mid-Level (MLM). A fim de efetivamente concretizar o gerenciamento baseado em P2P, foram introduzidas definições de blocos básicos para sistemas de gerenciamento baseados em P2P. A integração desses blocos básicos com soluções tradicionais de gerenciamento, tal como a estrutura SNMP, também foi apresentada. Um dos conceitos centrais da arquitetura apresentada são os Serviços de Gerenciamento, que definem as tarefas básicas de gerenciamento do sistema, e foram inspirados nos conceitos de Web Services e na concepção de serviços das Arquiteturas Orientadas a Serviço (SOA). Para a avaliação desse novo modelo de gerenciamento de redes e da arquitetura associada, surgiu a necessidade do desenvolvimento de um protótipo do sistema, com o intuito de servir como uma plataforma para desenvolvimento e implantação de Serviços de Gerenciamento. Esse protótipo é usado para avaliação e análise de testes e resultados associados. Para preservar as características de disponibilidade e escalabilidade que são inerentes dos sistemas P2P, definiu-se que os Serviços de Gerenciamento devem ser disponibilizados por Grupos de MLMs, organizados de forma a fazer a distribuição de tarefas de gerenciamento entre si. Diversos modelos de distribuição de carga foram investigados, foram realizadas avaliações e gráficos comparativos, e foram estabelecidas diretrizes sobre quando e como deve ser aplicado cada modelo, de modo a alcançar sempre o melhor rendimento e a maximização do aproveitamento dos recursos disponíveis ao sistema. A avaliação realizada consistiu na execução de diversas requisições com diferentes números de MLMs usando diferentes algoritmos de distribuição de carga, e na comparação entre a vazão, os tempos de resposta e o tráfego de rede gerados pelos diferentes casos de uso. A implementação desenvolvida neste trabalho demonstrou ser promissora, apresentando resultados bastante satisfatórios com relação aos parâmetros avaliados. / Due to the increasing complexity of computer systems, deep changes have occurred in network management in the past few years. Traditional centralized models have been proved limited, and new network management models are being proposed and investigated. In this scenery, P2P communication models allow for the creation of dynamic and versatile environments, able to solve problems in various computational areas, one of them being network management. The P2P model fits perfectly in the current demands of distributed network management. Starting from the proposed P2P-based network management model, a new P2P-based network management architecture has been developed, focusing on entities like Top-Level (TLM) and Mid-Level (MLM) management peers. With the purpose of making the P2P-based network management real, new building blocks for P2P-based network management systems have been defined. In the present work, an integration of these new building blocks with traditional network management solutions - like SNMP - is presented. One of the main concepts of the proposed architecture is on Management Services, inspired by Web Services and in the service definition of Service Oriented Architectures (SOA). To evaluate this new network management model and its associated architecture, it was necessary to develop a prototype system to be used as platform for development and deployment of Management Services. This prototype was used for evaluation, testing and result analysis. To hold the characteristics of availability and scalability that are inherent to the P2P systems, the Management Services had to be served by MLM groups, organized in a way to distribute the management tasks between them. Several load distribution models were investigated, with evaluation and comparative graphics fulfilled, and some guidelines were established as to when and how each model should be applied to reach the best performance and the maximization of the computational resources available to the system. The evaluation consisted in the execution of several requests in groups with distinct MLM numbers and using distinct load distribution algorithms. Then, the response time and network traffic generated by use cases were compared. We then showed that the developed implementation of our proposal is promising, and presents good results in relation with the evaluated parameters.

Devido à evolução e à crescente complexidade dos sistemas computacionais, grandes mudanças ocorreram na área de gerenciamento de redes. Os modelos tradicionais centralizados se mostraram limitados, e novos modelos de gerenciamento de redes estão sendo propostos e investigados. Neste cenário, modelos de comunicação P2P permitem a construção de ambientes dinâmicos e versáteis capazes de resolver problemas de diferentes áreas da computação, entre elas o gerenciamento de redes. O modelo P2P torna-se atrativo porque se encaixa perfeitamente no gerenciamento de redes distribuído atualmente solicitado. A partir da proposta de gerenciamento de redes usando P2P e da apresentação de um novo modelo conceitual usando essa nova perspectiva, foi desenvolvido um projeto de arquiteturas para gerenciamento baseadas em P2P, focando-se em entidades tais como peers de gerenciamento Top-Level (TLM) e Mid-Level (MLM). A fim de efetivamente concretizar o gerenciamento baseado em P2P, foram introduzidas definições de blocos básicos para sistemas de gerenciamento baseados em P2P. A integração desses blocos básicos com soluções tradicionais de gerenciamento, tal como a estrutura SNMP, também foi apresentada. Um dos conceitos centrais da arquitetura apresentada são os Serviços de Gerenciamento, que definem as tarefas básicas de gerenciamento do sistema, e foram inspirados nos conceitos de Web Services e na concepção de serviços das Arquiteturas Orientadas a Serviço (SOA). Para a avaliação desse novo modelo de gerenciamento de redes e da arquitetura associada, surgiu a necessidade do desenvolvimento de um protótipo do sistema, com o intuito de servir como uma plataforma para desenvolvimento e implantação de Serviços de Gerenciamento. Esse protótipo é usado para avaliação e análise de testes e resultados associados. Para preservar as características de disponibilidade e escalabilidade que são inerentes dos sistemas P2P, definiu-se que os Serviços de Gerenciamento devem ser disponibilizados por Grupos de MLMs, organizados de forma a fazer a distribuição de tarefas de gerenciamento entre si. Diversos modelos de distribuição de carga foram investigados, foram realizadas avaliações e gráficos comparativos, e foram estabelecidas diretrizes sobre quando e como deve ser aplicado cada modelo, de modo a alcançar sempre o melhor rendimento e a maximização do aproveitamento dos recursos disponíveis ao sistema. A avaliação realizada consistiu na execução de diversas requisições com diferentes números de MLMs usando diferentes algoritmos de distribuição de carga, e na comparação entre a vazão, os tempos de resposta e o tráfego de rede gerados pelos diferentes casos de uso. A implementação desenvolvida neste trabalho demonstrou ser promissora, apresentando resultados bastante satisfatórios com relação aos parâmetros avaliados. / Due to the increasing complexity of computer systems, deep changes have occurred in network management in the past few years. Traditional centralized models have been proved limited, and new network management models are being proposed and investigated. In this scenery, P2P communication models allow for the creation of dynamic and versatile environments, able to solve problems in various computational areas, one of them being network management. The P2P model fits perfectly in the current demands of distributed network management. Starting from the proposed P2P-based network management model, a new P2P-based network management architecture has been developed, focusing on entities like Top-Level (TLM) and Mid-Level (MLM) management peers. With the purpose of making the P2P-based network management real, new building blocks for P2P-based network management systems have been defined. In the present work, an integration of these new building blocks with traditional network management solutions - like SNMP - is presented. One of the main concepts of the proposed architecture is on Management Services, inspired by Web Services and in the service definition of Service Oriented Architectures (SOA). To evaluate this new network management model and its associated architecture, it was necessary to develop a prototype system to be used as platform for development and deployment of Management Services. This prototype was used for evaluation, testing and result analysis. To hold the characteristics of availability and scalability that are inherent to the P2P systems, the Management Services had to be served by MLM groups, organized in a way to distribute the management tasks between them. Several load distribution models were investigated, with evaluation and comparative graphics fulfilled, and some guidelines were established as to when and how each model should be applied to reach the best performance and the maximization of the computational resources available to the system. The evaluation consisted in the execution of several requests in groups with distinct MLM numbers and using distinct load distribution algorithms. Then, the response time and network traffic generated by use cases were compared. We then showed that the developed implementation of our proposal is promising, and presents good results in relation with the evaluated parameters.

Vid dimensionering av en byggnad är det viktigt att stabiliteten kan garanteras. För att kunna garantera stabiliteten så måste de krafter som en byggnad kan förväntas utsättas för kännas till. För horisontella laster syftar innebär det till lastfördelningen krafter i det horisontalstabiliserande systemet. Syftet med arbetet var att undersöka om FEM-design fördelar vindlast likt traditionella handberäkningar. Detta genom att jämföra resultaten av lastfördelning för de båda beräkningsmetoderna på ett referenshus. Referenshuset betraktas i fyra olika utföranden där dem varierar beroende på styvheten i skjuvväggar och bjälklag. Det för att beakta olika dimensioneringssituationer. Lastfördelningen för de olika utförandena har klarlagts genom att beräkna reaktionskrafter i grunden samt tvärkrafter i väggar. Styvhetsförhållande mellan skjuvväggar och bjälklag kontrollerades för att undersöka hur lastfördelningen till väggarna skulle ske. För två av referenshusets utföranden var bjälklaget vekt i förhållande till skjuvväggarna, för vilket fall litteraturen föreslår att lasten fördelas som för en kontinuerlig balk på fasta stöd. Vid jämförelse av handberäkningar och FEM-design så visade det sig att dem inte överensstämde speciellt bra. FEM-design gav en jämnare lastfördelning vilket istället påminner om ett utförande som litteraturen föreslår för en konstruktion med samma styvhet i väggar som i bjälklaget. Vidare utredning visar att det sannolikt beror på de olika metodernas sätt att beräkna styvhet för KL-trä. Baserat på de analyser som har gjorts i arbetet så kan det konstateras att lastfördelningen för byggnader bestående av styvt bjälklag med samma styvhet i skjuvväggarna överensstämmer för de olika beräkningsmetoderna. För utförandet med styvt bjälklag och olika styvheter i väggar så avviker resultaten. Sannolikt beroende på de olika metodernas sätt att beräkna styvhet för KL-trä. / The stability of the structure must be ensured when designing a building. To ensure the stability, the forces which a building can be exposed for must be known. In case of wind loads it means forces in the horizontal stabilizing system. The purpose with this project was to examine if FEM-design distribute wind loads like traditional hand calculations. This by comparing the results of load distribution for both calculation methods on a reference building. The reference building is designed in four different versions where the stiffness in the walls and the floor is what separate them. That to observe different design situations. The load distribution has been clarified by calculating reaction forces in the ground and shear forces in the walls. The stiffness ratio between the walls and the floor has been calculated to examine the load distribution on the walls. Calculations showed that the floor was weak in relation to the walls for two of the building’s versions. A ratio which the literature suggests that the load distributes like a continuous beam on fixed support. When hand calculations where compared to FEM-design the results did not agree very well. FEM-design gave a more uniform distribution of the loads, which reminds of a design the literature suggests for a structure with the same stiffness in the walls as in the floor. Further research indicates that it probably due to the different methods way of calculating stiffness for CLT. Based on the research done in this project it can be stated that load distribution for buildings with stiff floors and walls with the same stiffness correspond for the different calculation methods. For buildings with stiff floors and different stiffness in the walls the results do not agree. Probably due to the different methods of calculating stiffness for CLT.

Eurokoderna som utgör svenska normer för verifiering av bärförmåga, stadga och beständighet är i en fortgående utvecklingsfas och är ibland svåra och tidsödande att tillämpa i konstruktionsarbetet. Normerna anpassas kontinuerligt efter att frågor debatteras i branschen och det är viktigt att användarna av Eurokoderna håller sig uppdaterade. Svårtolkade begrepp och definitioner tillsammans med en omständig struktur i Eurokoderna skapar merarbete för användarna. Detta examensarbete sammanställer nödvändig information samt undersöker och utvecklar tillhörande begrepp för två ämnen, lastnedräkning och stomstabilitet. Examensarbetet kommer likt en handbok kunna användas i vardagligt konstruktörsarbete för att snabbt hitta rätt i Eurokoderna och bidra till att reda ut oklarheter kring de två berörda ämnena. Beräkningsexempel är upprättade som praktisk vägledning för respektive ämne där Eurokoderna tillämpas och hänvisas till. Examensarbetet är inriktat på handberäkningar. Dessa handberäkningar kan ligga till grund för initiala bedömningar av ett bärverks dimensioner och övergripande stabilitet men även vara ett stöd i beräkningar i bygghandlingsskeden. / The Eurocodes, which serve as the Swedish standards for verification of mechanical resistance and stability, are in an ongoing development phase and are sometimes difficult and time consuming to apply in the design process. The standards are continuously adapted to issues debated in the industry and it is important that users of the Eurocodes keep themselves up to date. Indistinct terms and definitions in the Eurocodes create, together with an inconvenient structure, extra work for users. This thesis compiles the necessary information and examines and elaborates terms related to two topics, load distribution and structure stability. Similar to a handbook, this thesis can be used in designer’s everyday work to quickly find the right Eurocodes and help sort out the confusion related to the topics in this thesis. Calculation examples are given as a practical guide where Eurocodes are applied and referred to. The thesis is focused on hand calculations. These hand calculations could act as a base for initial assessments concerning structure dimensions and overall stability as well as a guide during final calculations for construction drawings.

No description available.

This article focuses on the distribution of backpack pressure on human body. We have noticed two interesting situations: whether the length of different backpack shoulder straps will change the pressure distribution of the backpack on the human body and whether different positions of the backpack load will change the pressure distribution of the backpack on the human body. To find the answer, we designed a backpack pressure detection system to collect data and use engineering software to analyse the data.We got the range that best fits the human body and the healthiest backpack: when the distance from the top of the backpack to the shoulder is about 1/5 of the length of the shoulder and the weight of the backpack is at the bottom of the backpack. At this time, the force of the three parts of the human body (shoulders, back) is the most uniform and relatively minimal. If the user wants to minimize the pressure on the shoulder, the shoulder strap of the backpack should be as short as possible. If the user only wants the pressure on the back to be minimal, the weight in the backpack is closer to the back, which is better for the back.

No description available.