Hello Miotti

EN 13480-3 does not directly give the 0,2% proof stress of P235GH material. As you point out, we have to go to a specification such as EN 10028. From my copy of that specification, at 20C (room temperature) the value of Rp0,2t is 235 MPa. The value of Rm is 360 MPa. Up to a temperature of 50C the f = min(Rm/2,4; Rp0,2(20C)/1,5) Thus, up to a temperature of 50C, the design stress is min(360/2,4; 235/1,5) = 150 MPa. Once the temperature goes over 50C, the stresses drop. For example, at 100C, Rp0,2%t is 198 MPa, thus f = min(360/2,4; 198/1,5) = 132 MPa. Just remember, up 50C, the design stress is based up the yield at 20C (or room temperature).