The ability to predict whether a given ballistic blunt object will penetrate a composite material structure or not is valuable; and if the penetration occurs, to have the ability to predict the residual velocity of the object is also valuable. Also of interest is the ability to predict the ballistic limit of any ballistic object-composite structure combination. Empirical methods have been employed generally, but the cost and time involved in large test programs is a major concern, and any means to reduce or limit this approach is desirable. Computational methods have been developed previously to determine whether a given ballistic object will penetrate a woven fibrous structure or a composite material structure. These methods showed promise when compared with the test data available and also provided the predicted residual velocity of the object if the structure was penetrated. The procedures model the impacted structure as a conical shell with the same macroscopic properties as the actual structures. The result was that the computational method showed a linear relationship between the maximum strain to failure with the striking velocity of the ballistic object. This was a result that was difficult to predict, but which is very useful. In the present paper these methods have been used, improved, and have been verified by additional test data that has been provided by several sources. The procedures have also been used to predict the ballistic limit for several ballistic object-composite structure combinations for which there is test data. These methods were also compared with the ballistic limit prediction methods of several other research authors and found to be quite adequate. The methods are useful in that only a very limited number of tests are needed to establish the failure strain as a function of the striking velocity for a given target structure. Then those methods can be used to predict whether any other blunt ballistic object of known mass, material shape, and striking velocity will penetrate that structure, and if it does, what the residual velocity will be. The methods will also provide the ballistic limit for any other ballistic object and that composite structure.
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