4 research outputs found
Enhancement in thermal and mechanical properties of bricks
A new type of porous brick is proposed. Sawdust is initially well mixed with
wet clay in order to create voids inside the brick during the firing process.
The voids will enhance the total performance of the brick due to the
reduction of its density and thermal conductivity and a minor reduction of
its compressive stress. All these properties have been measured
experimentally and good performance has been obtained. Although a minor
reduction in compressive stress has been observed with increased porosity,
this property has still been larger than that of the common used hollow
brick. Data obtained by this work lead to a new type of effective brick
having a good performance with no possibility that mortar enters inside the
holes which is the case with the common used hollow bricks. The mortar has a
determent effect on thermal properties of the wall since it has some higher
thermal conductivity and density than that of brick which increases the wall
overall density and thermal conductivity of the wall
Finite element analysis of spot laser of steel welding temperature history
Laser welding process reduces the heat input to the work-piece which is the main goal in aerospace and electronics industries. A finite element model for axi-symmetric transient heat conduction has been used to predict temperature distribution through a steel cylinder subjected to CW laser beam of rectangular beam profile. Many numerical improvements had been used to reduce time of calculation and size of the program so as to achieve the task with minimum time required. An experimental determined absorptivity has been used to determine heat induced when laser interact with material. The heat affected zone and welding zone have been estimated to determine the effect of welding on material. The ratio of depth to width of the welding zone can be changed by proper selection of beam power to meet the specific production requirement. The temperature history obtained numerically has been compared with experimental data indicating good agreement