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The tear opening study is conducted with an example from the Tetra Pak package industry, the Tetra Top package. The top of the package is constructed by a injection molded low density thermoplastic. The package is opened with a tear opening located on the top part. In order to make tear opening more versatile, studies how opening forces reacts upon material modifications and alternative geometry h
Beverage packages made of paper and plastic materials that are stored for a long time, deform due to creep deformations. The phenomena is termed bulging and means that the package changes its shape. Bulging is a major issue for the producers of beverage packages. The purpose of this master’s dissertation, is to develop a Finite Element-model for simulation of bulging of beverage packages at varyi
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
Det har blivit allt vanligare med direkthandel i stora enplansvaruhus, där kunder plockar sina varor direkt från pallställ. Dessa pallställ går ofta från golv till tak och är lastade med varor ända upp till taket. I taket förekommer ofta fackverksbalkar i stål som bär upp stomsystemet. Vid en eventuell brand i ett pallställ kan det bli stor lokal flampåverkan med snabb upphettning i delar av fackve
