Papers by Keyword: Topology

Abstract: Footsteps are a foothold for motorbike riders and passengers; they also play a role in maintaining stability when driving. Footsteps must have a solid and lightweight material to support the load from the feet and body of the rider and passengers. In this study, the footstep with the material made from the waste drum brake shoe varied by reducing mass through the static structural simulation process and topology optimization process using Ansys Workbench to get optimal mass, total deformation, equivalent stress, maximum principal stress, and safety factor from each variation. The footstep geometry will be subjected to a load of 1000N and provided with the necessary support. Based on the data obtained during this study, the initial footstep geometry produces data in the form of total deformation (1.383 mm), equivalent stress (21.013 MPa), and safety factor (1.227). The 10% variation produces data in the form of total deformation (1.4368 mm), equivalent stress (20,564 MPa), ,and safety factor ( 1.2538). The 20% variation yields data in the form of total deformation (0.98037 mm), equivalent stress (18.111 MPa), maximum principal stress (18.41 MPa), and safety factor (yield strength: 1.4236,. At the same time, the 25% variation produces data in the form of total deformation (1.3058 mm), equivalent stress (22.27 MPa), and safety factor (1.1577).

Abstract: Fused deposition modelling (FDM) is a spectrum of techniques that enables the fabrication of objects from diverse materials, layer-by-layer, and directly from a CAD file. With the advancement of technology, the procedure has grown more adaptable and swifter. In this study, the mechanical performance and topology optimization of the polylactic acid (PLA) 3D printed hollow and thin-walled structures produced by FDM was investigated via integration of Taguchi method and Principal Component Analysis (PCA). Eleven factors namely topology design (square), wall thickness (1 mm), layer height (0.3 mm), infill density (20%), infill layer thickness (0.6 mm), infill flow (80%), infill pattern (Octet), print speed (80 mm/s), printing temperature (210°C), bed temperature (65°C), and orientation direction (flat along the y-axis) were identified as the optimal factors for the 3D printed part. The integration approach concurrently solves the problem in particular for numerous quality criteria, especially in 3D printing. Integrating the Taguchi method with PCA can help to improve the quality of the final product or process, and enhance the understanding of the underlying relationships between variables.

Abstract: Trabecular bone, widely presented in the ends of long bones and chine, is a typically porous structure which provides a multifunction such as light weight, undertaking load, impact energy buffer and hosting marrow cells. The structure of trabecular is a dominant factor for the strength of cancellous bone. The prediction of the trabecular bone’s mechanical properties depending on the trabecular structure is very useful for the diagnosis and treatment of osteoporosis. The object of this study is to establish a relationship between the mechanical properties and topological, morphological parameters of trabecular bone. The 50 3-D data of cancellous bone are selected from the CT images of three caput femurs and disposed in BoneJ, through which the BV/TV, SMI and genus parameters of each samples are obtained. The deformation behaviors of trabecular bone are simulated in ABAQUS through uniaxial compression on the 3-D model derived from stack images. Then linear-regression analyses are conducted on the BV/TV, genus, SMI and apparent Young’s modulus, resulting a high correlation (R^2=0.84) between the Young’s modulus and the hybrid parameter derived from SMI and normalized genus, corresponding to morphological and topological parameter of the samples respectively. The result indicates that it’s promising to establish the relationship between mechanical properties of trabecular bone and their topological and morphological parameters.

Abstract: This paper addresses the development of a foot structure for 22-Degree of Freedom (DoF) humanoid robot. The goal of this research is to reduce the weight of the foot and enable the robot to walk steadily. The proposed foot structure is based on the consideration of cases where the ground reaction forces are set up in different situations. The optimal foot structure is a combination of all the topology optimization results. Additionally, a gait pattern is generated by an approximated optimization method based on Response Surface Model (RSM) and Improved Self-Adaptive Differential Evolution Algorithm (ISADE). The result is validated through dynamic simulation by a commercially available software called Adams (MSC software, USA) with the humanoid robot named KHR-3HV belonging to Kondo Kagaku company.

Abstract: Proved the possibility of using amorphous aluminosilicate as a modifying agent for the adhesive dry mixes. The presented the technology of preparation of the additive based on amorphous aluminosilicates. Presents data on the influence of additives on the basis of amorphous aluminosilicates change the topological structure of cement stone.

Abstract: The present paper investigates the evolution of the WC grain size and morphology with the number of produced parts. Four reduction dies used in cold forward extrusion of steel are taken from the production line: a brand new die and three dies which have respectively produced 100.000, 150.000 and 220.000 parts. 3D roughness measurements and SEM micrographs are performed on the contact surface of each die. Results of these analyses highlight that WC grains are subject to plastic strain and are removed from the surface as the number of produced parts increase, leading to a growth of WC free areas where steel adhesion may occur. When analyzing the size of the WC grains, it appears that the population of small grains increases with the number of produced parts until 150.000. Then the population of small grains decreases. A wear mechanism is proposed to explain this variation of WC grains size with the number of extruded parts.

Abstract: The topology of electron density is a sketch that gives a clear picture about electronic distribution and details information of natural molecular bonding. In quantum mechanics or particularly in quantum chemistry, the electron density is a measure of the probability of an electron occupying at any infinitesimal element of space surrounding at any given point.Studies about the topology of electron density in Cd_0.5Zn_0.5S at plane (101) were conducted by the application of density functional theory (DFT) within linear augmented plane wave (LAPW) by using the WIEN2k software. In this calculation, generalized gradient approximation (GGA) methods were used to calculate the exchange-correlation potential of the electrons. Based on this calculation, the topology of electron density were presented in a contour plot (2D) and also inarelief map plot (3D) in order to see the way electron density, ρ of Cd_0.5Zn_0.5S defines the gradient field and hence the bonding type. From these plots, we identified the bond paths that coincide with the contours of electron to suggest that Cd_0.5Zn_0.5S exhibited characteristics of covalent and a slightly ionic bond character.

Abstract: With the further development of power electronic devices, matrix converter has many excellent properties. As high power factor converter equipment, matrix converter will have a great potential for its development. After reviewing the current situation from both domestic and abroad, this paper describes the key technology of Matrix Converter, including topology, modulation strategy and commutation problems. Finally make a summary of matrix converter operation’s enhancement and improvement of the ability of the method in abnormal conditions.

Abstract: The distributed renewable energy sources as wind, photovoltaic, fuel cell, wave are getting more and more attention and research due to the continuous deterioration of environment and constant stress of energy crisis. In this paper, several widely used topologies in transformerless PV inverter are introduced at the beginning. Then, the pros and cons of various topologies are discussed and evaluated in detail with respect to leakage current, efficiency and cost. The final conclusions derived can be regarded as references for design of highly efficient single-phase photovoltaic generation system.

Abstract: For awareness of the network situation, this paper proposes a set of indicators that can assess the importance of nodes and links combining with network topology and traffic information, their generating algorithm is given at the same time. Under the premise of determined network routing protocols, this algorithm is capable of assessing the importance of nodes and links based on the structure and operation state of network. In this way, it can show the special property of the unit position in the network, and can reflect the impact to each part due to the network state change so that network administrators can manage network reasonably.