This research applies SLSV (Single-Loop-Single-Variable) method to reliability-based topology optimization (RBTO) for frame structures to improve computational efficiency. The design problem is formulated to minimize the structural volume of frame structure in terms of crosssectional area of each frame element under the two reliability constraints. The two mode reliability criteria consist of the mean compliance and mean eifenfrequency criterion under variations on applied loads and nonstructural mass. Through numerical examples, higher computational efficiency and accuracy of reliability approximation by the SLSV method are demonstrated in comparison with those by the conventional double loop method that mode reliabilities are evaluated by the first order reliability method (FORM). Additionally, the importance of normalization of the limit state functions that are directly applied as constraint conditions in the SLSV method is also demonstrated.
