Papers by Keyword: Optimal Design

Abstract: Today, there are many different types of shaped steel with different characteristics, designed to meet the different needs of modern buildings. The most common is H-shaped steels, I-shaped steels and V-shaped steel. Shaped steel is hard and durable, with high tensile strength, and can withstand strong vibrations. When subjected to harsh conditions due to the impact of chemicals, the temperature should be kept suitable for industry and construction. Beams are designed for strength, so that they can resist the internal shear and moment developed along their length. To design a beam in this way requires the application of shear and flexure formulas, provided the material is homogeneous and exhibits linear elastic behavior. Although some beams may also be subjected to axial force, the effects of this force are often neglected in design, since it is generally much smaller than the stress developed by shear and bending. To optimize the design of the I-beam, the CAD model was developed in Inventor Professional 2019, and we used the Shape Generator module to determine the best design. In addition, these models also employ finite element analysis to determine whether the designs created are safe. This research also aims to assess long-standing traditional structures.

Abstract: Due to the intensive development of composite materials and technologies for producing parts from them, they are increasingly used in various industries, including the manufacture of products with increased requirements for the characteristics of final products (strength, stiffness, minimum weight, etc.). In this regard, the authors analyzed the possibility to optimize the layered structure of a composite material in order to give it a pronounced predictable anisotropy of properties required for the final product. Thus, the influence of the orientation of the fibers of the reinforcing material in different layers of the package and the number of layers of the package on the physical and mechanical characteristics of the hypothetical product were analyzed. The problem was solved through the example of the development of a wing for a hypothetical UAV.

Abstract: A support vector machine (SVM) is widely used for predicting the properties of fly ash blended concrete. However, the studies about the optimal design of fly ash blended concrete based on SVM are very limit. This study shows an SVM-based optimal design procedure of fly ash blended concrete. First, we built an SVM model and evaluated the compressive strength of fly ash blended concrete considering the effects of water to binder ratio, fly ash replacement ratio, and test ages. Second, we made parameter studies based on the SVM model. The parameter studies show that fly ash can improve the late age strength of concrete. This improvement is obvious for concrete with lower water to binder ratio. The optimal fly ash replacement ratio increases as the water to binder ratio decreases.

Abstract: Hetero-structure of Al_xGa_1-xN/GaN exhibits important applications in high frequency and large power devices. In this paper, AlN/GaN is adopted to optimal design the large power impact avalanche transit time (IMPATT) and mixed tunneling avalanche transit time (MITATT) diodes operating at the atmospheric low loss window frequency of 0.85 THz. The static state and large signal characteristics of the devices are numerically simulated. The values of peak electric field strength, break-down voltage, avalanche voltage, the maximum generation rates of avalanche and tunneling, admittance-frequency relation, output power, conversion efficiency, quality factor of the proposed hetero-structural IMPATT and MITATT diodes are calculated, respectively. Via comparing the obtained results of (n)AlN/(p)GaN and (n)GaN/(p)AlN IMPATT diodes to those of the MITATT counterparts, there exists little performance difference between IMPATT and MITATT devices while implies significant difference between the (n)AlN/(p)GaN and (n)GaN/(p)AlN diodes.

Abstract: The orthogonal experiment method is used in optimal design of laser cladding, such as laser power (P), scanning speed (SS), powder feeding rate (PFR) and shielding gas velocity (SGV) etc. Both the dilution rate and the aspect ratio are investigated by comprehensive scoring method, which transforms multi-index into single index. In view of the nonlinear characteristics of laser cladding process parameters, the optimum level of each factor based on interaction effect is obtained by analyzing binary tables. Finally, the relationship between the laser cladding process parameters and the two indexes (the dilution rate and the ratio of width to height of coating) is obtained. This method has potential applications for the further investigating on the laser cladding process rules.

Abstract: Multiphase transport processes are encountered in many branches of science and engineering. Bubbles can be used, for example, as to cut off the blood flows that feed sick tissue growth and as potential drug delivery systems. This paper addresses the effect of bubbles on the increase of flow resistance within optimized Y-shaped tubes under different size constraints (volume, surface area). Y-shaped constructs of fluid streams can mimic the anatomy of the vascular system, and the results presented in this paper can be used for facilitating the design and analysis of the flow of bubbles through these systems.

Abstract: The solution to the problem of designing rational load-bearing structures should be associated with the direct use of the principles that govern the deformation of a solid. If the functional of the direct problem has as Euler – Lagrange equations and natural boundary conditions the equations and boundary conditions of the accepted deformation theory, then they must correspond to the functional of the design problem, in addition, to additional equations indicating the dependence of the system energy change on the configuration change and the elastic modules of the body material. Possible variations of the configuration functions and modules of elasticity of the material will be infinitely small changes of the functions satisfying the prescriptive requirements to the structure and material; they are continuous and satisfy the requirements of differentiability. Due to the small variations in the functions that determine the configuration, we neglect changes in the arrangement of external forces relative to individual parts of the body and changes in the temperature field.

Abstract: In this research, a new type of magneto-rheological brake (MRB) is proposed for small size motorcycle. The proposed MRB consists of a rotor with multiple trapezoidal teeth acting at multiple magnetic poles of the brake. In order to generate a magnetic field for controlling braking torque, a magnetic coil is placed on each side-housing of the brake. The inner face of each side-housing also has trapezoidal shape mating with the trapezoidal teeth of the rotor via MRF layer. By applying countercurrents to the coils, a magnetic fluid is generated with some magnetic flux going across the MRF layer (MRF duct) between the rotor teeth and their mating poles on the housing. By using multiple poles with trapezoidal shape, a high braking torque of the brake is expected while the size of the brake is still kept to be compacted. After an introduction about the development of MRBs in automotive engineering, the configuration of the proposed MRB is presented and its braking torque is derived based on Bingham rheological model of MRF. The proposed MRB is then optimally designed based on finite element analysis (FEA). Its optimized MRB is then manufactured and its braking performance is experimentally investigated. The MRB is then installed in a prototype motorcycle and the field test of this prototype motorcycle integrated with the MRB is then conducted.

Abstract: Aluminum-plastic composite panel is a kind of new type energy-saving and environmental-friendly curtain wall decorative material, and is widely used in building exterior wall, curtain wall board, old building reconstruction and renovation and other projects. With the development and improvement of production and application technology, the performance and functions of aluminum-plastic composite panel products have been optimized continuously; especially at present, all countries in the world have more and more strict requirements on fire safety, and the fire safety standards of buildings also have been improved continuously. In this context, all the manufacturing enterprises have been actively developing new techniques to produce new type aluminum-plastic composite panels, and have significantly improved the fireproof and flame-retardant properties of the products on the basis of ensuring all the performance levels of the products being acceptable. This paper proposes optimal design suggestions via detection analysis on three groups of aluminum-plastic composite panel samples, and is of important practical significance to the research and development of the aluminum-plastic composite panel with low-combustion-heat and flame-retardant core material.

Abstract: Next generation aircraft rely heavily on lightweight honeycomb composite structures for improved electromagnetic wave scattering and stealth capabilities. This paper investigated the optimal design and analysis methods of multi-layer absorbent honeycomb composite structures. The effective electromagnetic parameters of anisotropic object were calculated accompany with the formulation of reflectivity for incident wave. A genetic algorithm is employed to optimize the RCS of the absorptive honeycomb composite in desired angle range. The thickness and the volume fraction of absorptive materials are adopted to optimize the effective electromagnetic parameters under different polarized modes. Single and multi layer absorptive honeycomb composite were been studied. The results show that the thickness of the first absorptive layer plays a key role on the reflectivity of honeycomb structure. Therefore, it is advised to arrange the absorptive layers such that the EM absorption properties increases from outside to inside.