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Methods for integrating Fortran based finite element applications in a scripting environment

The course Software Development for Technical Systems at the division of Structural Mechanics teaches students techniques for implementing finite element applications with both user interface and computational code. Currently Borland Delphi environment is used for the user interface and Fortran is used for the computational part. This master’s thesis is an effort to study methods of integrating Fort

Optimering av balktvärsnitt med avseende på bärförmåga

SSAB Tunnplåt AB manufactures high strength steel to e.g. beams to trailers, containers, trucks and cars. In high strength steel designs the ratio width to thickness is also high and therefore the risk for local buckling is high. When buckling occurs the stress will re-distribute and large deformation will occur. It is therefore important to take buckling into consideration when dimensioning high

Analysis and Measurements of Vehicle Door Structural Dynamic Response

In order to reduce lead time and cost in the product development of vehicles more development will be made virtually. However, the predictability capability of simulation models is questioned and the simulation models need to be correlated versus hardware measurements and modeling techniques improved. As part of the process of vehicle system model capability improvements the main objective of thi

Dynamic Behaviour of Footbridges Subjected to Pedestrian-Induced Vibrations Studies

Over the last years, the trend in footbridge design has been towards greater spans and increased flexibility and lightness. As a consequence, stiffness and mass have decreased which has lead to smaller natural frequencies and more sensitivity to dynamic loads. Many footbridges have natural frequencies that coincide with the dominant frequencies of the pedestrian-induced load and therefore they have

Longitudinal Sealings in Beverage Packages - Experimental Testing and Numerical Parameter Studies

In this work, the mechanical behavior of longitudinal sealings in paper based beverage packages have been investigated trough experimental tests and Finite Element simulations. The mechanical performance of the longitudinal sealing is of great interest when developing and improving beverage packages. Choosing a suitable sealing type is both a performance and cost issue, therefore is better knowled

Windloads and Buildingaerodynamics

Today there exists standards which describes how wind-loads, statical and dynamical, can be treated for different kinds of buildings. In some cases these standards are to coarse which might result in results that aren’t precise enough. This might be the case when structures interact with the wind and creates resonance phenomenons between the structure and the wind. Accurate calculations of the airfl

Bolt fixings in toughened glass

Research needs: Glass has been used for a long time, mostly in the window and packaging industry, but lately architects and design engineers have become more and more interested in glass as a load-bearing (building) material. It has become a challenge to use less other materials in the glass-structures or at least not to let it show too much. One area of big interest is bolt fixings. Design engine

Strength and Creep Analysis of Glued Rubber Foil Timber Joints

In this master’s thesis, the possibility of increasing the load bearing capacity of glued timber joints by the use of a rubber foil was investigated. A rubber foil is believed to ensure a more uniform distribution of stresses and thereby greater load bearing capacity. The work within this master’s thesis consisted of developing material models for rubber based on experimental tests in order to en

Strength Analyses of Wooden I-Beams with a Hole in the Web

Wood-based light-weight I-beams are today widely used in the construction industry. An important feature of these beams is that the user can make holes in the web where needed. Today there is no general method used to calculate the reduced strength of these beams with a hole in the web. The calculation methods vary between the manufacturers and are commonly based on empirical results. The aim of t

A New H-Adaptive Method for Shell Elements in LS-Dyna

This thesis describes the development of a new h-adaptive method for shell elements in the explicit FE-code LS-DYNA. Adaptivity is used to obtain accurate results for large deformation analyses to a low computational effort. However, the present adaptive method available in LS-DYNA is based on a geometrical simplification. When the mesh is refined, the bending deformation of the shell is not consi

Acoustic Analysis of Loudspeakers Cavity Including Viscothermal Effects

The geometry of a loud speaker cavity often gets a complicated geometry with sharp corners and narrow ducts. For this kind of shape the internal energy losses caused by viscosity and thermal conduction play an important role in the acoustic behavior. Today there is no method that sufficiently predict these effects. In this report the analogy between the loudspeaker cavity, a simple mass and spring sy

Moisture Induced Stresses and Deformations in Parquet Floors - an Experimental and Numerical Study

The indoor climate conditions in buildings have changed in the last decade due to more efficient climatic systems, floor heating systems and larger open floor areas with more natural light. These factors all give increased annual variations in the humidity and the temperature in parquet floors. Such variations can result in troublesome deformations, glue line delamination and development of cracks

A finite element based design tool for point fixed laminated glass

In this master’s project, a design tool for bolt fixed laminated glass was developed, based on linear-elastic finite element theory. The program produces images of the deflections and stress distributions in bolted glass panes. A two-dimensional triangular mesh, created by an external mesh generator, was extended to a three-dimensional mesh comprising 15-node wedge elements. A least-square method was

Analys av jord och konstruktion i samverkan - Utvärdering av olika FE-program

When building below ground level in cities the regulations regarding deformations of surrounding soil are very strict. When using conventional methods of calculation it is difficult to predict the occurring deformations. This is why it has become more common to use FE-modeling to determine deformations. With FE-modelling it is possible to take the interactions between soil and construction into co

Simulering av betong under härdning

Concrete hardens as a result of chemical reactions between water and cement. Cement is a hydraulic binder, in the reaction the cement binds water-molecules. This is an exoterm process, heat is produced during the reactions. How fast this process proceeds is much depending of the temperature. The amount of heat produced during the hardening of the concrete is also depending on the thickness of the

Sömn och sömnvanor hos personer med schizofreni

Studier visar att sömnbesvär vid psykiska besvär förekommer relativt ofta. Undersökningar visar även samband mellan schizofrenisjukdom och sömnproblem. Det råder brist på studier där man undersökt personer med schizofreni gällande deras erfarenheter kring sin sömn och sina sömnvanor. Syftet med studien var att undersöka hur dessa personer upplever sin sömn. Tio personer med schizofreni inom rättsp

Licensavtalsautonomi – Om licensavtalets bestånd vid felaktiga förutsättningar

Licensavtal spelar en betydelsefull roll för att olika typer av immateriella rättigheter ska kunna utnyttjas på ett ekonomiskt effektivt och ändamålsenligt sätt. Istället för att behöva investera stora mängder kapital för att kunna omsätta sina idéer eller sin framtagna design till faktiska produkter, kan en rättighetsinnehavare erhålla relativt snabb och säker avkastning genom att någon annan – eLicensing agreements play a critical role in the enabling of economically efficient and purposeful ways to exploit intellectual property rights. Instead of having to invest large amounts of money, time and energy to turn one’s ideas, designs or creative expression into actual products, an intellectual property owner can obtain a reasonably swift and reliable return by letting somebody else – a lic

When is hearing believing: The effects of professional experience on voice identification accuracy

The purpose of the study was to examine differences in the accuracy of voice identification tasks between an experimental group (N = 56) consisting of security personal, and a control group (N = 44). In addition, calibration methodology was employed in order to examine if the experimental group exhibited a higher confidence level in their identifications than the control group. No significant diff