Modelling and Simulation in Engineering

The squeezed multiple-branch pile is a variable section pile that was built by adding a bearing branch cavity to a constant section pile using expansion and extrusion equipment. It is widely used in engineering practice for its high bearing capacity, small settlement deformation, high economic benefits, strong adaptability, and simple pile forming process. In this paper, a new type of squeezed multiple-branch pile is proposed and its forming tool is invented. The forming tool of the pile has applied for an invention patent and is authorized by the China National Intellectual Property Administration. Multiple groups of comparison models of the new squeezed multiple-branch piles are established by using FLAC3D numerical simulation software to investigate the influence of the number and spacing of branches on the bearing mechanism in response to uplift load. The results indicated that the number and spacing of branches have a significant effect on the uplift bearing capacity, load–displacement curves, side friction resistance, and stress distribution law in the new pile and soil around the pile. The suitable number and spacing of branches maximize the uplift bearing capacity and minimize the settlement of a single pile.

With the development of the Internet, traditional platforms have been challenged by competition from participants on the platform. However, it is unclear how these two types of population, which are in competition but also mutually dependent, can co-exist in the new platform ecosystem. This paper sheds light on that key phenomenon by extending the population density logistic model of the e-commerce platform ecosystem between participants and platforms based on the symbiosis theory. By solving the logistic equation, we acquire the evolutionary trajectory and final size of populations under different symbiotic patterns. The results reveal that the cooperative and competitive effect determines the equilibrium outcome of the symbiosis evolution of e-commerce platform ecosystem. In the asymmetric symbiosis mode, only one population is influenced by positive synergy that increases population density and promote evolution. The contribution coefficient of subordinate to the dominant is greater than the feedback coefficient from the dominant; the trends of output value are inconsistent. The symmetric symbiosis mode is the optimal model for participants and platforms. The effect “” can only be achieved under the symmetric symbiosis mode, and the growth of the participants and the platforms is more stable and sufficient than that in other modes. The findings will provide additional perspectives to promote the sustainable development of e-commerce platform ecosystem considering the cooperative and competitive effect.

Recycling and sustainability constitute a major challenge to preserve human life quality and ensure a good standard of living for future generations. Like other recyclable waste products, glass waste can be a major problem if it is not recycled. When glass waste is turned into powder, environmental impacts are minimized by reducing or eliminating the dependency on landfills. Within this context, the objective of this work is to design a low-cost glass crusher machine that can be acquired by individuals. For this purpose, a glass crusher machine based on the ball mill concept is designed to transform glass waste into powder of 2 mm particle size. The main enhanced features of this machine with respect to state-of-the-art designs are the continuous feed aspect and the powder discharge technique. The design methodology consisted of mathematical modeling coupled with numerical simulations to ensure a safe and functioning design. This was achieved via different types of simulations using SolidWorks: static stress analysis, free vibration analysis, and motion study. Finally, a market study shows that a breakeven period is reached after a period of 5 months.

The flow in the bend channel used as spillway chute is complex due to the turbulence, the presence of shock waves, and vibrations. These transverse waves can damage the hydraulic structure. Our aim in this paper is to investigate the distribution of water surface in five curved channels with five relative curvatures , different bottom slopes (1%, 2%, 10%, and 18%) and three different cross-sections. The objective is to give a solution to reduce the height difference between the inner and the outer walls. To achieve this goal, we used physical models to investigate the flow patterns, explore critical zones, and test several solutions to have a better performance. The reliability and accuracy of the numerical results were validated using the physical modelling for each case tested. Moreover, a comparison between the measured data, theoretical calculations, and numerical outcomes was done, to find a fitting law between the maximum wave height and the bend number. Furthermore, an optimal position of the guide wall was identified in real project of a spillway. The results of the physical model and numerical simulation show a good agreement; thus, the numerical model can play a crucial role in order to study hydraulic parameters, pressure, and velocity field and find solutions for hydraulic problems that occur in these structures.

In this paper, a saltwater intrusion model, in view to study the dynamics of the interface between the saltwater and the freshwater in a coastal aquifer, is established. This dynamic is caused by an injection of saltwater and a freshwater pumping through a well located in a given position. From the flow model in each phase, we defined an appropriate hypothesis to obtain our global model based only on the height of the interface. The numerical simulation of our model led us to study the effect of the parameters and obtain some empirical laws of the pollution time versus the distance well-injection area and pollution time versus the pumping flow.

The study presents results of computer simulation by finite elements method of a new metal forming process combining the deformation of a billet with round cross-section on a radial-shear rolling mill and subsequent billet twisting in a forming die with a specific design. To analyze the efficiency of metal processing, the main parameters of the stress–strain state are considered: effective strain, effective stress, average hydrostatic pressure, and Lode–Nadai coefficient. The maximum value of effective strain up to 13.5 is achieved when a screw profile on the billet in the die is forming, which indicates an intensive refinement of the initial structure of the billet. During combined process, the nature of the deformation changes in the transverse direction from the axis of rotation to the surface. The central area of the billet is under the action of tensile stresses. In the peripheral part, compressive stresses grow. In the surface area, Lode–Nadai coefficient is 0.1 approximately, which indicates the high level of shear strain.