Element 1 - Testing & Analysis
Task 1.3.2: Development of Testing Protocols
PI: Helmut Krawinkler (Stanford University)
Common testing protocols must be developed for all testing programs of Task 1 of the Woodframe Project. These testing protocols must reflect the realistic seismic demands expected on woodframe buildings and must consider the dynamic characteristics of these buildings.
The objective of Task 1.3.2 is to establish common testing protocols for all component tests and shake table tests for the Woodframe Project. For shake table testing, single- and multi-axis excitations for different seismic hazard levels should be established. The proposed loading histories for cyclic testing should be representative of the seismic demands imposed on components and structures under the following conditions:
• Ordinary ground motions that represent design events envisioned by present codes.
• Near-fault ground motions.
• Multiple earthquakes occurring in the lifetime of the structure.
The development of loading histories for seismic performance testing requires the execution of time history analysis that captures the demand characteristics peculiar to the wood structures of interest in the Woodframe Project. These demands are evaluated through simulation studies in which representative single and multi degree of freedom systems are subjected to ground motions of various characteristics.
The demands are represented in loading histories that simulate, in a cumulative manner, the damage experienced by the system or component. Representative structures of different periods are subjected to various sets of ground motions, utilizing a versatile hysteresis model capable of representing the stiffness degradation and strength deterioration characteristics of various wood components.