Mi sección está clasificada como clase 4 y no es calculable en RF-/STEEL CSA. However, my manual calculation shows a different class. Why the difference?

Q: Mi sección está clasificada como clase 4 y no es calculable en RF-/STEEL CSA. However, my manual calculation shows a different class. Why the difference?

Las razones máximas b/t y h/w se basan en la tabla 1 o la tabla 2 dependiendo de los esfuerzos internos en las barras. For members subject to pure axial compression, Table 1 is used. For members subject to flexure or flexure+axial (beam-column), Table 2 is used.In RFEM, the preset setting is to neglect the bending moment if the ratio is less than 1%. Therefore, the program shows “Class 4” since the check is based on Table 1.To change this setting, go to Details and set the limit values to zero (as shown in Image 1). By doing so, the program runs the check per Table 2 and no longer ignore the small moments.Note: In the example model, where moments are zero at the support locations, the result is still shown as “Class 4 (non-designable)”.

Question

Mi secci&#243;n est&#225; clasificada como clase 4 y no es calculable en RF-/STEEL CSA. However, my manual calculation shows a different class. Why the difference?

Accepted Answer

Las razones m&#225;ximas b/t y h/w se basan en la tabla 1 o la tabla 2 dependiendo de los esfuerzos internos en las barras. For members subject to pure axial compression, Table 1 is used. For members subject to flexure or flexure+axial (beam-column), Table 2 is used.In RFEM, the preset setting is to neglect the bending moment if the ratio is less than 1%. Therefore, the program shows “Class 4” since the check is based on Table 1.To change this setting, go to Details and set the limit values to zero (as shown in Image 1). By doing so, the program runs the check per Table 2 and no longer ignore the small moments.Note: In the example model, where moments are zero at the support locations, the result is still shown as “Class 4 (non-designable)”.

Sección CSA S16 Clase 4

Mi sección está clasificada como clase 4 y no es calculable en RF-/STEEL CSA. However, my manual calculation shows a different class. Why the difference?