A displacement-based Rayleigh-Ritz finite element model is developed to simulate the static and dynamic behavior of stiffened plates. By con1paring natural frequency, time-history, and power density predictions with experimental results, it is shown that the model can be used to predict the vibratory behavior of wood floor systems constructed With either solid-sawn joists, I-Joists, or parallel-chard-trusses. Furthermore. using the model. it is shown that appropriate structural modifications can be used to improve the performance of wood floor systems by increasing natural frequency and reducing peak time-history velocity. Using the techniques described. a design example is included that indicates ho,v floor acceptability can be achieved. / Ph. D.