Our early model for predicting nonwoven fabric stress-strain behavior by the finite element method is generalized to include the effects of fiber curl, which is shown to have a great effect on the tensile behavior of the fabric. A numerical method to characterize the lateral contraction of nonwovens during tensile deformation is presented. The effects of fiber arrangement characteristics on the mechanical properties of nonwovens are studied through laboratory experiments and theoretical analysis. The effects of varying thick nesses within the nonwovens on fabric strength, modulus, and stress-strain distribution are also examined. Tensile testing of several nonwoven fabrics verifies the theoretical results.