Performance control based on green tree behavior

This article presents a realistic analogy, with practical applications, between green trees and manmade moment frames under similar loading conditions. The paper also introduces a new facet of bioinspiration which attempts to benefit from some of the natural design strategies involved in the structural performance of trees, rather than utilizing them as raw materials. The paper suggests that bioinspiration can help transfer and improve basic design concepts from trees to moment frames under seismic as well as gravity loading scenarios. For instance, it has been shown that earthquake resistant systems can best be realized by performing design led analysis rather than investigating analytic results and that structural design should be performance based rather than instruction oriented computations. In other words, it is preferable for earthquake resistant structures to be designed in accordance with observed rather than expected behavior, i.e., desirable response characteristics should be induced rather than investigated. These features constitute the core of the recently developed performance control (PC) methodology that aims at rational design of engineering structures under both service as well as extreme loading conditions. In the interim a number of new design formulae have also been introduced. Two examples have been provided to demonstrate the applications of the conceptual design similarities between green trees and earthquake resisting moment frames.