Monotonic Tests of Wood-frame Shear Walls with Various Openings and Base Restraint Configurations
This report aims to quantify the effects of overturning restraint on full-size wood frame shear walls with and without openings tested monotonically and to determine the applicability of the empirical perforated shear wall design approach to conventionally built walls without considering overturning restraint provided by hold-down devices or gravity loads. It provides information useful in determining at what wind and seismic force level the different amounts of overturning restraints are required for a given wall configuration. The authors performed monotonic tests to determine the performance under static or wind loading. Findings of the report include: 1) A shear wall containing the maximum amount of tie-down anchors utilizes overall material strength most efficiently, but the performance improvements may not be justified, depending on construction costs and design criteria. 2) For walls with overturning restraint at the ends of the wall and walls with maximum overturning restraint, ultimate capacity was reached when sheathing nails of both, OSB and gypsum wallboard started to tear through, and when the panel edges started to fail in compression. 3) Walls with no overturning restraint failed due to nail tear through and stud separation along the bottom plate and these walls had the lowest stiffness and capacity. However, the performance appears adequate for many design conditions where the expected lateral loads are low to moderate in magnitude. This is especially evident if smaller structures are considered along with the effects of gravity loads and restraint from corner framing. 4) The data suggest that the empirical perforated shear wall design approach gives conservative design values for all wall configurations. The amount of conservatism increased with increasing opening size in the wall.