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The modeling clay is an oil-based soft, flowable, and pliable material made from waxes and oils. Besides its primary use for making sculptures, the modeling clay is commonly used to evaluate bulletproof vests and simulate metal manufacturing processes by conformation. In ballistic tests, the clay is used to retain the deformation of the rear face of body armors; and in the study of metal forming processes, it is used as a physical model to provide information on the plastic flow. However, its mechanical dynamic behavior is not entirely understood. In this study, Plastilina Roma No. 1 modeling clay was mechanically characterized using the power-law constitutive model at medium strain rates (10 2 s − 1). The material parameters were determined using a penetration model based on the Cavity Expansion Theory and an inverse technique involving the comparison of the model with experimentation. The optimum set of constitutive parameters was found by reducing the difference of the calculated penetration profile and the measurements from a drop test. This optimization process was programmed on the MATLAB–Simulink environment. The determined material parameters were validated by comparing the results from a computational model with three test set-ups. Finite element model results show good concordance with experimental measurements. [ABSTRACT FROM AUTHOR]

In this work a natural fiber composite material, the Guadua Angustifolia Kunth from the family of Bamboo is investigated as a suitable alternative for solutions for impact applications, load-bearing, and other structural applications. Since this type of Bamboo grows faster than wood and requires less water and area to reach maturity and be able to crop, it is a competitive, economically, and environmentally solution when is compared to other construction materials. The Bamboo species of interest is a natural one from Colombia and will be evaluated in flexural behavior and under impact response to understand the material subjected under fast loading. Flexural samples were cut parallel to bamboo axial fibers to obtain the highest impact strength. The flexural tests and scanning electron microscopy characterization were included for microstructure analysis. Additionally, compression at high strain rates was characterized by a split-Hopkinson pressure bar (SHPB). Results show flexural strength of about 70 MPa. The impact analysis showed a tough material with very similar values to Charpy notched and dynamic instrumented impact tests. [ABSTRACT FROM AUTHOR]