EFFECT OF DEFLECTION SPEED ON RACKING RES ISTANCE OF BRACED AND PLYWOOD SEATHED WALLS

A fast speed racking test was condusted on plywood sheathed walls and braced walls. The walls were subjected to +/-100 mm deflection cycles of sine waves, and triangle waves. The frequencies were 0.125. 0.25. 0 .50, 0.75, and 1 Hz, of which deflection speeds corresponds to 5, 10, 20, 30, and 40 cm/sec. in the cases of triangle waves, and pi/2 times these speeds in the cases of sine waves. No effect of the deflection s peed on the racking resistance was observed, The deflection speeds of wood structures subjected to powerful seismic forces is in the above r anges. From these results, it can be said that the damping resistance which is proportional to the deflection speed of a structure should be ignored in seismic response analyses.