Unbraced Length

Software analyzes a member based on a beam stability factor of 1.0; where the member has adequate lateral bracing such that there is no reduction to the allowed moment capacity. To determine the unbraced length, software effectively works backward by first calculating the beam stability factor as a ratio of the actual moment applied and the allowed moment capacity. This ratio value is then used to solve for the maximum unbraced length required to maintain that beam stability factor. Ultimately, if the member was braced at ONLY the defined maximum unbraced length, it would be fully stressed because the allowed moment capacity should be reduced by the beam stability factor. If the user makes any changes to the applied load, software reanalyzes the member to provide a new unbraced length.