analytical methods needed to be used to determine the correct material properties for the sand. In addition, studies were conducted to determine the best methods of simulating the boundary conditions present in the test. In “Ballistic Impact Testing of Aluminum 2024 and Titanium 6Al-4V for Material Model Development,” Pereira et al. present asetofballistictestsonaluminumandtitanium flatpanelspecimens. The goal of the experimental program was to develop a set of highquality impact data suitable for use in impact simulations conducted using these materials. The ballistic limit and residual projectile velocity after impact were determined for each of the specimens. Cylindrical projectiles were used for the smaller specimens, whereas projectiles meant to simulate the features of an actual engine fan blade were used for the larger specimens. The effects of parameters suchasfrictionandprojectilehardnessontheimpactresponseofthe panels were also determined. In “Macromechanical Approach to Modeling Barely Visible Damage in Braided Composites,” Blinzler and Binienda describe a computationally efficient methodology developed to analyze the architecturally dependent impact damage in braided polymer composites. The braided composite is simulated as a series of parallel laminated composites. In the presented paper, the application of the method to model barely visible damage under impact conditions is presented. Specifically, the application of cohesive elements between layers of the braid to simulate the damage before penetration in the braided composites is presented. In “Analytical Model and Numerical Analysis of the Elastic Behavior of Triaxial Braided Composites,” Zhang et al. describe the development of a detailed mesomechanical finite-element model of a triaxially braided polymer matrix composite. The procedures used to determine the detailed geometry of the finite-element model based on detailed examination and measurements of micrographs of the actual composites are presented. Methods to determine theeffectiveelasticpropertiesoftheimpregnated fibertows,including the effects of fiber undulation, are described. The effective elastic properties of the braided composite are presented. The effects of factors such as edge effects and fiber tow undulation on the overall elastic response of the braided composites are discussed. In “Enhancements to Modeling Dry Fabrics for Impact Analysis,” Deivanayagam et al. present methods to model aircraft engine fan containment systems composed of dry Kevlar fabric. A constitutive model is described, and the coupon level tests required to characterize the constitutive model are discussed. Furthermore, the simulation of large-scale ballistic impact tests of structures composedoftheKevlarfabricarepresented,andcomparisonsbetweenthe experimental results and the analytical simulations are presented.