The design of building structures requires consideration of both strength and stiffness. For strength design, methods that permit the use of K=1 are very convenient. This engaging session introduces the Indirect Analysis Method, a simplified form of the Direct Analysis Method (DM) that substitutes an amplifier on lateral loads for the DM modeling requirements. Many structures are drift-controlled, meaning that the design process is intended to result in (or approach) a known second-order drift: the drift limit. Methods of determining force and displacement amplifiers based on first-order drift may give very approximate results or require iteration if a target second-order drift is used. This session develops equations based on second-order drift for amplifiers on first-order analysis quantities used for approximate second-order analysis and for the design for stability. Handouts can be found here.
Source: NASCC Year: 2020 Speaker(s): Rafael Sabelli; Larry Griffis