Simplified Models for Composite Elastic Behavior of Precast Concrete Insulated Wall Panels

This paper outlines a new simplified method for predicting the degree of composite action (percent composite) and thus the elastic moment of inertia and the elastic section modulus for precast concrete insulated wall panels. This simplified approach was developed by using 1 million simulations from the iterative sandwich beam theory method. The overall bias (average ratio) of the linear approximation on the simulated test dataset is 1.0 for both cracking and deflection, and the overall coefficient of variation (COV) is 0.04 for cracking and 0.03 for deflection. When compared with data from previously published experiments, the new method has a bias of 1.02 and COV of 0.32 in cases where the experiment conforms to the assumptions of the new method. By comparison, the reported biases of other available methods, which are more complicated to use, range from 0.97 to 1.06, and the COVs of other available methods range from 0.16 to 0.32. Thus, the level accuracy of the new method to predict the percent composite is similar to the levels of accuracy of the more complicated approaches.