Square Steel Tube To Hollow Spherical Steel Welded Joints After Fire Effects

Due to significant importance of joints their use plays an important role as a connection pattern and crucial zone for space lattice structures to transfer the structural load all the way down to the substructure.The concept of hollow spherical steel welded Joints that have been implemented long ago because of its remarkable performance and light in weight.To avoid or minimize the stress concentration of joints the use of steel joints has been increasing in the construction projects of developing countries.From three decades because of innovation in hollow steel joint structure of architecture,the cast steel joint structure becoming complicated day by day.To reduce the rest stress which is generated in the difficult territory by conventional welding technology,and fulfill the criteria of structure stress also structural construction,the hollow spherical steel joint along with a best quality and strength gain attention being a significant portion of huge buildings.The fire damaging effect has been consider one of the most important engineering problems in steel structures more specifically hollow spherical steel welded joints that need to be consider and should be given the priority based on its inheriting performance in steel structures.It is common that recently design codes are reflected during the fire states steel connections which will be frenzied with slow speed as compared with beams or columns,however,minimizing the probability then they will be consider a perilous components in fire safety design.Considering the importance of hollow spherical joints to steel tube in the spatial structures,thirty nine different models of which twenty two without ribs in the interior part of the hollow spherical joints and seventeen with ribs were introduced using finite element software ABAQUS.On the behalf of general static method,Non-linear finite element analysis was carried out to check the performance of hollow spherical joints to square steel tube against different elevated temperatures.Axial load–displacement relationships were generated of the proposed models on two different air and water cooling method.From the results it’s shown that water cooling method on load carrying capacity of the proposed connections produce significant effect after fire effect as compared to air cooling method.Based on parametric analysis it’s determined the load carrying capability of the proposed models later fire effect greatly derived by the thickness parameters of square steel tube,hollow spherical joints,and depth of ribs.With the increasing the thickness parameters of steel joints the performance of spherical joints in terms of axial-displacement significantly increased later fire effect.