Investigation of the torsional restraint of sandwich panels against lateral torsional buckling of beams

Experimental investigations and parametric FE-analyses show that the torsional restraint of sandwich panels against lateral torsional buckling of beams can be expressed by a tri-linear moment-rotation-relationship. Formulae are given for different profile types combined with sandwich panels for roof and wall for calculation of the parameters of this relationship. From this moment-rotation-relationship, which depends on the lateral load of the beam, the rotational stiffness c(upsilon A) of the connection is obtained as secant stiffness. The rotational stiffness c(upsilon) required for the design against lateral torsional buckling according to DIN 18800 part 2 is governed by c(vA). The rotational stiffness values c(upsilon A) of the connection, which so far were only known for two types of elements, can be calculated with this method for all common types of sandwich panels and different types of constructions.