Sökning: "Materialmekanik"

Visar resultat 21 - 25 av 41 avhandlingar innehållade ordet Materialmekanik.

1. 21. The silicon nitride reaction-bonding process

   Författare :Bingqiang Lei; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : The so called Reaction-Bonded Silicon Nitride (RBSN) materials are usually produced through the chemical reaction of silicon powder compacts in a nitriding atmosphere. This nitriding reaction is strongly exothermic and much heat is generated, which may cause to overheating, even melting of the powder compacts so to hinder the further reaction due to the reduction of specific area of the powder compacts, especially when the nitridation involves a rather large mass of silicon. LÄS MER

3. 22. Deformations and stresses in butt-welding of plates : numerical simulation and experimental verification

   Författare :Lars-Erik Lindgren; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : Deformation and stresses in butt-welding of plates were studied. The work includes numerical simulation and experimental verification. The simulations were performed by use of the finite element method. Temperature dependence of material properties and phase transformations were considered. LÄS MER

4. 23. Experimental and computational investigation of the roll forming process

   Författare :Michael Lindgren; J Huetink; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : One of the first questions to consider when designing a new roll forming line is the number of forming steps required to produce a profile. The number depends on material properties, the cross-section geometry and tolerance requirements, but the tool designer also wants to minimize the number of forming steps in order to reduce the investment costs for the customer. LÄS MER

5. 24. Modelling and simulation of the roll forming process

   Författare :Michael Lindgren; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : One of the first decisions to make when a new roll forming line is designed is the number of forming steps needed to produce a profile. This is dependent on the material properties, the cross-section geometry and the tolerance requirements. LÄS MER

7. 25. Modelling of Bulk Metallic Glass formation in Powder Bed Fusion

   Författare :Johan Lindwall; Andreas Lundbäck; Mattias Unosson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Material Mechanics; Materialmekanik;

   Sammanfattning : This thesis discusses a model for simulation of the Powder Bed Fusion (PBF) process of metallic powder with the capability to become amorphous. The temperature field in the PBF process is predicted by a three-dimensional thermal finite element model in three dimensions using a layer-by-layer approach, meaning that the scanning strategy of the moving laser spot is consolidated into a single heat source acting on the entire layer momentarily. LÄS MER