No

A fundamental investigation of the use of ultrasonic consolidation (UC) to produce deck panels for small satellites was undertaken. Several fabrication methods for producing structural panels and decking were analyzed. Because of its ability to create aluminum objects in an additive fashion, and at near-room temperatures, UC was found to be a powerful solution for creating highly integrated and modular satellite panels. It also allowed a lightweight and stiff deck to be fabricated without the use of adhesives. A series of experiments were performed to understand the issues associated with creating a sandwich-type structure using UC. The experiments used a peel test apparatus to evaluate the bond strength for various geometric configurations and materials. Aluminum 3003 was chosen as the sole material constituting the deck panel. The honeycomb lattice was found to offer the best core configuration due to its ability to resist vibration from the sonotrode and provide adequate support for pressure induced by the sonotrode. Support materials for enhancing the bonding of the facings to the core were investigated but did not lead to implementation. A CAD model was created to integrate the honeycomb core, facings, and modular bolt pattern into the ultrasonically consolidated structure. The model was used to develop a build procedure for fabricating the deck on the UC machine. A finite element analysis was performed that used an equivalent properties method to represent the deck. The stiffness of a prototype deck was evaluated in a three-point bending test and the results were found to correlate with the finite element model. A sine sweep vibration test was then performed on the prototype deck panel to measure its natural frequencies. Finally, a case study was performed on a deck built for the TOROID spacecraft. A final deck panel was designed using the results from the prototype. The deck included the USUSat bolt pattern, vented honeycomb, and a reinforced rim. The cost and benefits of the final deck panel versus traditional fabrication methods were outlined.

Plank (tongue and groove) wood decking is a product that is commonly used in post and beam timber construction to transfer gravity loads on roofs and floors. In 2010, The National Building Code of Canada changed the application area of the specified concentrated roof live loads from 750 mm x 750 mm to 200 mm x 200 mm. The change was made to better reflect the area which a construction worker with equipment occupies. Preliminary analysis showed that the change in the application area of concentrated loads may have a significant impact on the design of decking systems. Little research or development has been done on plank decking since the 1950’s and 1960’s. An experimental program was undertaken at the University of Ottawa’s structural laboratory to better understand the behaviour of plank decking under uniformly distributed and concentrated loads. Non-destructive and destructive tests were conducted on plank decking systems to investigate their stiffness and failure mode characteristics under uniformly distributed as well as concentrated loads. The experimental test program was complimented with a detailed finite element model in order to predict the behaviour of a plank decking system, especially the force transfer between decks through the tongue and groove joint. The study showed that the published deflection coefficients for uniformly distributed loads can accurately predict the three types of decking layup patterns specified in the Canadian Design Standard (CSA O86, 2009). For unbalanced uniformly distributed loads on two-span continuous layup, it was found that the deflection coefficient of 0.42 was non-conservative. It was also found that under concentrated loads, the stiffness of the decking system increased significantly as more boards were added. A deflection coefficient of 0.40 is appropriate to calculate the deflection for the three types of decking layup patterns specified in the Canadian Design Standard (CSA O86, 2009) under concentrated load on an area of 200 mm by 200 mm. Significant load sharing was observed for plank decking under concentrated loads. An increase in capacity of about 1.5 to 2.5 times the capacity of the loaded boards was found. Furthermore, it was found that placing sheathing on top of a decking system had a significant effect in the case of concentrated load with an increase of over 50% in stiffness and over 100% in ultimate capacity.

Thesis (M.S.)--Oregon State University, 2005. / Printout. Includes bibliographical references (leaves 83-87). Also available on the World Wide Web.

Plank (tongue and groove) wood decking is a product that is commonly used in post and beam timber construction to transfer gravity loads on roofs and floors. In 2010, The National Building Code of Canada changed the application area of the specified concentrated roof live loads from 750 mm x 750 mm to 200 mm x 200 mm. The change was made to better reflect the area which a construction worker with equipment occupies. Preliminary analysis showed that the change in the application area of concentrated loads may have a significant impact on the design of decking systems. Little research or development has been done on plank decking since the 1950’s and 1960’s. An experimental program was undertaken at the University of Ottawa’s structural laboratory to better understand the behaviour of plank decking under uniformly distributed and concentrated loads. Non-destructive and destructive tests were conducted on plank decking systems to investigate their stiffness and failure mode characteristics under uniformly distributed as well as concentrated loads. The experimental test program was complimented with a detailed finite element model in order to predict the behaviour of a plank decking system, especially the force transfer between decks through the tongue and groove joint. The study showed that the published deflection coefficients for uniformly distributed loads can accurately predict the three types of decking layup patterns specified in the Canadian Design Standard (CSA O86, 2009). For unbalanced uniformly distributed loads on two-span continuous layup, it was found that the deflection coefficient of 0.42 was non-conservative. It was also found that under concentrated loads, the stiffness of the decking system increased significantly as more boards were added. A deflection coefficient of 0.40 is appropriate to calculate the deflection for the three types of decking layup patterns specified in the Canadian Design Standard (CSA O86, 2009) under concentrated load on an area of 200 mm by 200 mm. Significant load sharing was observed for plank decking under concentrated loads. An increase in capacity of about 1.5 to 2.5 times the capacity of the loaded boards was found. Furthermore, it was found that placing sheathing on top of a decking system had a significant effect in the case of concentrated load with an increase of over 50% in stiffness and over 100% in ultimate capacity.

No / This paper presents a numerical investigation into the behaviour of headed shear stud in composite beams with profiled metal decking. A three-dimensional finite element model was developed using general purpose finite element program ABAQUS to study the behaviour of through-deck welded shear stud in the composite slabs with trapezoidal deck ribs oriented perpendicular to the beam. Both static and dynamic procedures were investigated using Drucker Prager model and Concrete Damaged Plasticity model respectively. In the dynamic procedure using ABAQUS/Explicit, the push test specimens were loaded slowly to eliminate significant inertia effects to obtain a static solution. The capacity of shear connector, load-slip behaviour and failure modes were predicted and validated against experimental results. The delamination of the profiled decking from concrete slab was captured in the numerical analysis which was observed in the experiments. ABAQUS/Explicit was found to be particularly suitable for modelling post-failure behaviour and the contact interaction between profiled decking and concrete slabs. It is concluded that this model represents the true behaviour of the headed shear stud in composite beams with profiled decking in terms of the shear connection capacity, load-slip behaviour and failure modes.

No / The main objective of this research is to develop an accurate and efficient nonlinear finite element model to study the behaviour headed shear connectors in composite beams with pairs of shear connectors. A numerical model for push test will be prepared to predict capacity, load-slip behaviour and failure modes of headed shear stud. The model will be verified against test results and after validation; it will be used to study the effect of various parameters on the performance of the shear connector.

No

En hållbar samhällsutveckling beror på tre faktorer; naturen, människan och samhället. I dagens läge vill människan minimera de påfrestningarna som miljön och omgivningen utsätts för. Det är därför viktigt att se över hur resurserna utnyttjas. Ett bra exempel på detta är att befintliga trafikleder inom tätbebyggda städer byggs över, sådana projekt kallas överdäckningar. På detta sätt skapas både byggbar yta och negativa effekter av trafikleder minskas inom tätbebyggda områden. Buller, barriärer och luftföroreningar är exempel på negativa effekter. Trots att överdäckningskonstruktioner har många fördelar som exempelvis ökad marktillgång är det många planerade projekt som stoppas. Detta på grund av explosionsrisker som anges i de nya lagarna och rekommendationerna av transport av farligt gods. För att underlätta framtida överdäckningar har författarna analyserat och diskuterat situationen samt klargjort vilka regelverk som gäller. Intervjuer utfördes med olika parter både i den offentliga och i privata sektorn. Detta för att få en bredare uppfattning om hur regelverken bör tolkas. Därefter har diskussioner framförts gällande konstruktionslösningar och åtgärder som kan tillämpas för att minimera konsekvenser av explosioner i en tunnel. I dagens läge finns det inga regelverk specifikt för överdäckning utan det är en sammansättning av regelverk för tunnel och hus. Om ovanliggande konstruktioners laster placeras direkt på tunneltaket finns det stor sannolikhet till att bebyggelsen kollapsar om taket viker sig. Det är då viktigt att jämföra olika olycksscenarior som kan tänkas inträffa för olika farligt godsmängder och transporter. Jämförelserna kan leda till en rimligare konsekvensuppfattning. Resultatet av detta har konstaterats i att det borde finnas specifika riktlinjer för överdäckningar men även att riskanalyser av olyckor bör analyseras på rätt sätt. / A sustainable society depends on three factors; nature, mankind and society. Presently, mankind has a need to minimize the stresses that the environment and our surroundings are exposed to. It is of the utmost importance that we focus on how to use our resources in new efficient ways. A perfect example of this is to build over current highways in urban cities areas. In Sweden this type of method when translated is called overdecking, internationally no collective term has been given. When building a tunnel a top a highway, new area is made available above for construction, and the negative effects caused by these infrastructures are removed. Noise barriers and pollution are examples of these negative effects. Although over decking have many benefits for expanding the society, many of these projects are being stopped. This is due to the risks that occur when dangerous goods are transported and how the laws and regulations govern this matter. To facilitate future projects the writers have analyzed and discussed the situation and clarified which rules apply. Interviews were performed with parties both in public and private sectors. This was done in order to get a broader perspective over how rules should be interpreted. Thereafter discussions were made regarding construction solutions that can be applied to minimize consequences of an explosion event in a tunnel. Presently there are no regulations specifically for over decking, but only a composite of the regulatory framework for tunnels and houses. If building loads are placed directly on the tunnel roof there is a strong likelihood that the house collapses if the roof folds.  It is therefore important to review accident scenarios that might occur with various degrees of dangerous transported goods and transportations. The result of this has led to that there should be specific guidelines for over decking structures, but also how risk assessments of dangerous goods accidents should be handled.

Thesis (Ph.D.)--University of Western Sydney, 2006. / A thesis presented to the University of Western Sydney, College of Health and Science, School of Engineering, in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographies.