Papers by Keyword: Smooth Particle Hydrodynamics

Abstract: Significant research is being conducted in the simulation of fluid flows due to the increase in employing the physics of the fluid flow to either commercial, in-house or open source codes. The analysis of the fluid flow is mainly based on the Lagrangian or the Eulerian approach. Many of the simulation codes employ the Eulerian approach due to its simplicity. These codes are based on several numerical techniques and yet few benchmarks have been conducted. However, the codes which employ the Lagrangian approach seem to be promising and may accurately simulate fluid flow phenomena. In this paper, a comparative analysis of the Lagrangian and Eulerian approach is investigated for a water droplet in a tank. The velocity field and the total pressure of the fluid are generated for the simulation by employing Ansys Fluent for the Eulerian approach and DualPhysics for the Lagrangian approach. The fluid structure and the fluid flow development are compared in order to assess the capability of each approaches in analysing the investigated fluid flow. This study may play a significant role on the importance of employing the Lagrangian approach for fluid flows where complex fluid structure occurs.

Abstract: SPH is a Lagrangian based computational method that can be used for solving fluids and solid mechanics problems. In this work, SPH is utilized to solve the two dimensional Navier’s equation for linear elastodynamics problems. The SPH technique computes the discrete particle properties using a smoothing distribution function, which takes into account the effect of neighboring particles. To investigate the performance of the developed method in solving solid mechanics problems, the problem of plate bending was simulated. The results show good agreement between the simulation and analytical solution. Additionally, the study found an indication that the current method of enforcing boundary conditions produces boundary effects at locations where the plate is attached to the wall and at the end of the plate.

Abstract: This paper presents some experimental results of a bullet impact on composite armor together with numerical modeling approaches. The development of light composite sandwiches for ballistic protection is the target of a project in terms of which the research is being conducted. Traditionally, a vehicle ballistic protection is mainly achieved through metal-based armor which is extremely heavy, hence the increasing popularity of composite sandwiches. Numerical simulations allow for a reduction of the number of experiments needed to obtain appropriate design of ballistic protection, but they require verified modeling approaches and proper material data. Therefore, different modelling approaches for both parts of the composite sandwich have been tested and possibilities to adjust these models to experimental data were investigated.

Abstract: Aircraft structures are frequently subjected to impacts from objects such as runway debris and birds. In new aircraft structural design, Fiber Metal Laminates (FMLs) play a significant role due to their excellent mechanical properties, particularly the impact properties. In this study, the aircraft sandwich wing with FML face-sheets are analyzed by finite element model for simulating the bird strike. The numerical simulations of bird strike impact are performed adopting a lagrangian approach to design the wing by MSC/PATRAN FE code. The numerical obtained results are compared with the results in the literature for validation of the model. The effect of fiber orientations, fiber types, metal types in FML face sheets in sandwich wing on impact responses are investigated. The impact responses are illustrated by displacement history, contact force history and energy absorption. According to these results, the sandwich panel with FML skin is suitable structure for energy absorption (that is the most important factor in impact phenomena). The lay-ups with titanium metal layer with aramid fibers are the best.

Abstract: The paper presents a fluid structure interaction based numerical study of impact loading for a hemispherical structure upon water and a space capsule water landing. The study has a strong relevance in the determination of the crashworthiness of aerospace structures upon water impact loading. Finite element based numerical techniques have been used for the analysis of the underlying transient dynamic and fluid-structure interaction. Smoothed Particle Hydrodynamics (SPH) and Arbitrary Lagrange-Eulerian (ALE) methods have been used to simulate the behaviour of the fluid (water) under impact conditions. The accelerations and velocities of the impacting objects have been validated with by experimental measurements and analytical results. Numerical analyses showed a strong potential for the use of developed computational fluid structure interaction models for analyses of water impact loading related problems.

Abstract: Cutting process of single abrasive grain was simulated by Smoothed Particle Hydrodynamics and Finite Element Method. Chip mechanism of single abrasive grain was analyzed according to the stress variation of grain and workpiece material, and motion situation of smoothed particles in cutting layer. Effects of abrasive grain rake angle and cutting depth on cutting deformation of workpiece material were also analyzed. It is concluded that workpiece material occurs to plastic deformation, flows to the side and front owing to the extrusion of abrasive grain, and finally forms chip in front of abrasive grain; cutting capability increases with the increase of abrasive grain rake angle, it results in the increase of material protrusion in front of abrasive rain and relatively decrease of material protrusion beside abrasive grain; workpiece material deformation and cutting force increase with the increase of cutting depth. Scratching experiment of abrasive grains was carried out by using vitrified bonded CBN block. It is found that deformation laws of workpiece material in the simulation and experiment are consistent. It is proved that the simulation results are correct, and the simulation method is feasible