ON THE INFLUENCE OF A FREE SUPPORT RAKE ON THE RIGIDITY OF A GIRDER BEAM
Pages 35-44
Analytical solutions have definite advantages over numerical ones. It is quite complicated to find solutions for a whole class of structures different in the number of bars or panels if we speak about girder trusses. The solutions obtained in a symbol form may be analytically investigated depending on all the parameters characterizing the structure. This allows educing the distinctive features of the systems and finding possibilities for optimization in terms of mass, strength and rigidity. At the present time the induction method is the most efficient to obtain analytical solutions for a number of trusses. Using computer mathematics system Maple the author obtained analytical expressions for deflection of a flat statically determinate parallel-flanged elastic truss depending on the number of panels at uniform and concentrated load. It is shown that the rake angle of a free support greatly influences the stiffness of a structure. The graphic charts of the dependence of deflection from the number of panels at a fixed span length and a given load show extremum. The author obtains asymptotic characteristics of the deflection and expressions for stresses in the most compressed and tension bars. It is also shown that the solution type for a deflection isn’t changed in case of different loading types and has a form of a polynomial of not more than third degree in correspondence with the number of panels in half of a span.
DOI: 10.22227/1997-0935.2016.10.35-44