Abstract in English:

Abstract To evaluate the residual strength of the ship after explosion, the Explosion Smith Method (ESM) is proposed. The innovation of the ESM lies in two aspects: firstly, based on the Baker shock wave and quasi-static pressure model, Jones critical velocity model, propose a method for assessing the range of explosion damage of cabin and validated through referenced experiments. Secondly, proposes the strain-stress relationship of the deformation element. To verify the feasibility of the ESM and study the influence of TNT location and mass,16 simulations and EMS calculations were conducted. The results showed that the residual strength is most impacted when the TNT in top deck. For side cabin, the explosion products discharged and impact reduced. The trend of the ESM and simulation were consistent, but the result of ESM was more severe. The reason that strain-stress relationship of the deformation element more stringent, resulting in the ESM smaller than the simulation. However, as the TNT increases the error decreases. In the future, more research can be conducted on the deformed structures to enhance the accuracy of the ESM.

Abstract in English:

Abstract In the classical literature devoted to the study of orthotropic materials under large strains, a lot of emphasis is given to strain invariants, obscuring the association of finite strain constitutive relations with well-established small strains constitutive relations. In this work, this association is established through the comparison of 8 orthotropic models (3 classical and 5 new) for hyperelastic orthotropic materials using the Flory’s decomposition. This is done transforming the initial formalism of different models into complete quadratic polynomials written in terms of the Right-Cauchy-Green stretch and a volumetric control that guaranties the growth condition. A tailoring fiber-reinforced solid model - in which discrete fibers are immersed into continuous matrix - is also presented and used to establish numerical tests, generating basic elastic constants for comparisons. The 5 proposed models are implemented in an in-house FEM code and comparisons among their mechanical behavior are presented. From these comparisons one of the proposed models is selected to successfully simulate a biological tissue, opening the possibilities for future studies.

Abstract in English:

Abstract The mathematical modeling of the dynamics of a two-layer shallow pipeline under the influence of transport load (the load created by an object moving along the pipeline) has been successfully resolved. The pipeline is represented as an extended circular cylindrical two-layer shell with a thin inner (bearing) layer and a thick outer (enclosing) layer situated in an elastic half-space. Dynamic equations of elasticity theory using Lamé potentials are utilized to describe the motion of the half-space and the enclosing layer of the shell. The vibrations of the bearing layer of the shell are described by the classical equations of the theory of shells. Numerical experiments have considered the case of a moving axisymmetric cylindrical normal load applied to a pipeline (without an enclosing layer and with an enclosing layer of varying thickness and material stiffness). It was demonstrated that if the material of the enclosing layer of the pipeline is more rigid than that of the rock mass, the dynamic effect of the moving load on the rock mass is reduced.