Sökning: "Sigurdur Ormarsson"
Visar resultat 1 - 5 av 7 avhandlingar innehållade orden Sigurdur Ormarsson.
Sammanfattning : Shape instability in timber products exposed to moisture variation is a serious problem since it can make wood products unsuitable for construction purposes. In this thesis the finite element method has been used to simulate deformations during the drying process.….…. LÄS MER
Sammanfattning : A 3D theory for the numerical simulation of deformations and stresses in wood during moisture variation is described. The constitutive model employed assumes the total strain rate to be the sum of the elastic strain rate, the moisture-induced strain rate, the mechano-sorption strain rate and the creep strain rate. LÄS MER
3. Moisture-induced stress and distortion of wood : A numerical and experimental study of wood's drying and long-term behaviour
Sammanfattning : With the current advances made in three-dimensional modelling of wood, it is possible to provide an overall picture of moisture flow, and moisture-induced stress and deformations, whereas previously, experiments only provided local measurements. The main aim of the doctoral thesis is to investigate the possibilities of the developed three-dimensional numerical model to predict the behaviour of wood when simultaneously exposed to a mechanical load and a particular climate. LÄS MER
Sammanfattning : Timber has become more popular as a construction material during recent years. Engineered wood products, such as glued laminated timber and cross-laminated timber, have enabled the construction of multi-storey buildings. Tall buildings with many occupants need to resist a disproportional collapse in case of unexpected exposures, e.g. LÄS MER
Sammanfattning : To design safe, reliable and durable timber structures subjected to varying natural outdoor or indoor climates, understanding the long-term behavior of wood when mechanically loaded or restrained to deform is crucial. The present thesis focuses on the numerical modeling of the long-term mechanical behavior of wood. LÄS MER