Description:
OBJECTIVE: Successful fielding of lightweight composite material components requires dependable material property data early in the design cycle. Full sets of laminate data can be costly and time consuming to generate. The objective is thus to develop the analysis techniques for reliable prediction of fiber reinforced polymer matrix composite material properties based on ply level material property data. DESCRIPTION: Fiber reinforced polymer matrix composite materials continue to rapidly improve in terms of structural performance. After a new material becomes commercially available, however, there is often a significant lapse in time before that material can be successfully integrated into a structure. Large amounts of data must be collected before there is adequate confidence in the material properties to invest in designing hardware with that material system. The laminate level material strength properties are heavily dependent on fiber orientation, and it is necessary to have thorough knowledge of these laminate level material properties for design. These properties are longitudinal and transverse tension and compression, longitudinal and transverse open hole tension and open hole compression, shear, bearing, and compression after impact. Currently available analytical tools have been repeatedly demonstrated to fall short in terms of their ability to reliably predict the aforementioned material properties based on ply level material property data. Having analysis techniques that can reliably predict laminate level material properties based on reduced sets of ply level material property data could prove invaluable early in the design cycle of fiber reinforced composite structures. This could greatly improve the rate at which advanced material systems mature and thus bring benefit to missile and aviation systems in terms of weight and insensitive munitions performance. PHASE I: Develop and demonstrate analytical approaches to predicting laminate level tensile and compressive coupon material strength properties with a limited amount of ply level material property data. Ply level data shall include unidirectional axial and transverse tension and compression material property data. PHASE II: Develop a modeling tool that allows the user to create a set of material property strength data for a pre-defined laminate. This modeling tool should be able to predict a set of material strength property data that includes tension, compression, open hole tension, and open hole compression all in both the axial and transverse directions. This predicted data set shall also include shear and bearing properties. The statistical nature of each of these properties should be able to be predicted using the modeling tool. Understanding the statistical nature of the predictions is key to getting reliable allowable material strengths early in the design cycle. The inputs to the analysis tool should be limited to basic ply level material property data as well as matrix material properties. This phase should successfully demonstrate the accuracy of the predictions across relavent environmental conditions including room temperature/dry, cold temperature/dry, and elevated temperature/wet. International Traffic in Army Regulation (ITAR) control is required. PHASE III: Weight reduction is of great importance in many aviation and missile structures. The ability to reliably predict laminate material properties using ply level material property data and understanding the accuracy of the predictions can drastically reduce the design cycle and allow the use of high performance material systems more quickly as they become commercially available. This technology can be used across a number of applications where weight reduction is important. This is considered pervasive technology and can be applicable to future weight reduction efforts for multiple Army systems including Javelin, JAGM, and TOW. It has the potential to find uses in both military and commercial applications. An example would be to create an analysis code that could be integrated into a commercial finite element analysis code such as Abaqus. This would allow users to quickly evaluate different laminates in their designs prior to committing to a material system early in the design cycle.
