in iran, for column design, double i shape section is used due to lack of ipb profile. double i shape column performance is ambiguous in existing steel structures, especially when subjected to seismic loading. in this paper, double i shape column behavior is evaluated with 3d nonlinear analyses. monotonic behavior of 6 specimens and hysteretic behavior of other six specimens have been simulated...

Rhythmic activity in complex systems is generated and sustained through interactions among the constituent units. In this paper we study the interplay between topology and dynamics of excitable nodes on random networks. The nodal dynamics are discrete, each node being in three possible states, active, refractory or silent. Loading rules are defined whereby a subset of active nodes may be able t...

Concrete is a material whose performance is governed by the subtle interaction of its cohesive and frictional constituents. Since the theories of plasticity, damage mechanics, and fracture mechanics cannot, by themselves, capture both of these phenomena, a novel constitutive model is proposed which combines the theories of plasticity and damage mechanics in a multi-surface formulation. Synthesi...