Fatigue damage on steel space truss systems

Searching of light, practical, fast and industrial solutions in structure technology produces the space truss systems.Space truss systems are formed by steel bars which are under axial tension or compression loads connected each other with nodes.These systems provide constructing wide span structures by light structural elements and also make buildings more powerful and useful.Space truss system elements must be dimensioned due to the loads they carry as dead, live, wind and earthquake loads.As other structural materials, space truss system materials which are subjected to cyclic loads can be damaged because of fatigue effect.And also if truss system is not protected from corrosion effect, the ratio of fatigue crack growth increases.In this paper; fatigue damage of a steel space truss system is studied under snow and thermal loads.Results are compared to four space truss systems which are collapsed from snow loads and it is seen that collapsing mechanism of these space truss systems and calculation results match.And also it is observed that; corrosion and structural irregularities are effective in failure of these systems.Precautions are given for preventing fatigue failure of space truss systems.