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In this paper, experimental investigation and theoretical analysis are carried out in an attempt to study the response of SiC ceramic matrix composite reinforced with three dimensional braided fabric(3D C/SiC) under high velocity impact. The results show that 3D C/SiC composite will be turned into comminution if the pressure of the impact point resulted from the projectile impacting 3D C/SiC composite sample is larger than 780Mpa. Based on the analysis of the mechanism of composite comminution, a theoretical model has been developed.

An adequate ductile fracture locus has to be developed to reasonably model crack initiation and propagation in high velocity impact. Most of the fracture loci in the literature were proposed on the basis of tensile tests while in high velocity impact cracks usually occur in the region where shear and compression are dominant. In this paper, perforation response of a thin beam struck by a rigid, blunt projectile moving at a high velocity is simulated using, respectively, uniform fracture strain, Johnson-Cook's, and Bao-Wierzbicki's fracture locus for 2024-T351 aluminum alloy. The former two predict that materials in the impacted area of the beam beneath the rigid mass fail layer by layer, which is not consistent with experimental observations. By contrary, Bao-Wierzbicki's fracture locus, which was developed from up-setting, shear and tensile tests, and covers the whole range of the stress triaxiality, is capable of capturing all of the features occurring in the whole failure process. Numerical results reveal that the beam would fail by shear plugging at a high impact velocity and by tensile tearing at a velocity near the ballistic limit.

For concrete target penetration and/or perforation simulation, the Holmquist–Johnson–Cook (HJC) material model is widely used as concrete material model. However, the strain rate expression of the model has failed to explain the sudden increase in concrete strength at high strain rates. The pressure-volume relationship of the HJC model is complex and requires a large number of material constants. In this study, a modified Holmquist–Johnson–Cook (HJC) model is proposed for concrete material under high velocity impact. The modification involves simplification and improvement of the strain rate expression and pressure-volume relationship. Material parameters identification procedure for the MHJC model is also elaborated. The numerical simulations using the proposed model show a good agreement with experimental observations, especially, on the residual velocities, penetration depths and failure patterns of the target plates. These validate the applicability of the MHJC model for high velocity projectile impact studies for concrete.

This paper presents the dynamic response of structures under high velocity impact loading using Smooth Particle Hydrodynamics (SPH) approach. The SPH equations governing the elastic and elasto-plastic large deformation dynamic response of solid structure are derived. The proposed additional stress points are introduced in the formulation in order to mitigate the tensile instability inherent in the SPH approach. The incremental rate approach is combined with the leap-frog scheme of time integration forming solution algorithm adopted in present study. Examples on high velocity impact of the solids are presented and results from the proposed SPH approach compared with available finite element solution illustrating that the transient dynamic response under high velocity impact can be effectively solved by the proposed SPH approach.

In this paper, the dynamic responses of structures under high velocity impact using smooth particle hydrodynamics (SPH) approach is presented. The SPH equations, which govern the elastic large deformation dynamic response of solid structure, are derived. The proposed additional stress points are introduced into the formulation to treat tensile instability. Furthermore, in order to increase the accuracy of SPH solutions, the novel incremental rate form approach was proposed by adopting the smoothing particle method. Combining the incremental rate form approach and the leap-frog algorithm for time integration, the new solution algorithm and formulation was developed and implemented. To examine the performance of the proposed algorithm, an example on structure dynamic response under high velocity impact is given. A comparison study on the results obtained from the proposed SPH approach and those obtained from the Finite Element Method (FEM) shows that the high velocity impact problem can be effectively solved by the proposed SPH approach.