Papers by Keyword: Parameter Optimization

Abstract: This study presents the characterization of 316L stainless steels fabricated by selective laser melting (SLM), focusing on the influence of printing parameters on microstructure and mechanical properties. The choice of process parameters is crucial for achieving desired material properties, as it directly affects the microstructure and mechanical behavior, which is important when optimizing for potential applications in several fields, such as aerospace and automotive. In this study, different scanning speeds were tested to identify optimal settings, followed by the evaluation of the effects of orientation relative to the build plate and hatching strategies to enhance performance. To assess the impact of these factors, tensile tests, microhardness measurements, and X-ray diffraction (XRD) analyses were conducted. Tensile tests revealed that higher laser scanning speed generally reduces ultimate tensile strength and elongation, likely due to an increase in porosity and a less homogeneous fusion of layers. The analysis of samples printed with different orientation relative to the build plate highlighted a strong mechanical anisotropy, with the samples printed vertically exhibiting lower tensile strength and ductility compared to horizontally printed samples. Microhardness testing further confirmed an anisotropy in material properties. XRD analysis reveals a preferential orientation of austenitic grains depending on building direction. This, in turn, influences the anisotropic behavior. These findings highlight the critical role of process parameters in tailoring the microstructure and mechanical performance of SLM-produced parts, thereby providing insights into the optimization of additive manufacturing for specific applications.

Abstract: The present work aims to understand the effect of drilling parameters (drill speed and feed rate) during the drilling of saffil fiber-reinforced Al metal matrix composite (MMC) under dry conditions. The effect of drilling parameters on individual response characteristics is evaluated and the optimum drilling parameters are also investigated using a multi-response optimization technique known as Entropy Weighted Grey Relational Analysis (EWGRA). The drilling parameter optimization has been performed with aim of minimizing the surface roughness of drilled hole, roundness error in drilled hole and feed force during drilling. Weights were assigned to individual responses with the Entropy weight method and Grey relational grades were calculated to obtain the optimal level for drilling parameters. To achieve the minimum values for all output responses the optimal value of drill speed is 22 m/min and the feed rate is 0.075 mm/rev.

Abstract: The bottom hole opening method is generally used to rescue the people trapped inside the capsized vessels. In this paper, a new sealed cabin with flexible cabin shell and rigid pedestal was proposed to rescue people in distress through the inner hole cut on the bottom hull. The parameters of the cabin pedestal and the sealed pedestal are optimized respectively to reduce the weight of the whole cabin. According to response surface methodology to analysis the relationship between the tress and the structural parameters. The maximum equivalent stress and maximum deformation are the constraint conditions and the total mass of the structure is the objective function, and the multi-island genetic algorithm is used to optimize the model, and the approximate optimal solution was finally obtained. The results show that the strength of cabin pedestal and sealing pedestal meet the application requirements.

Abstract: In this work, Sn₄P₃ powders were successfully synthesized by mechanical alloying route and the relative processing parameters were optimized in details, including the weight ratio of Sn/P, milling duration, Al powders doping and sintering treatment. Based on the microstructure analysis of products, the optimal weight ratio of Sn/P was determined as 5:1, closing to the stoichiometric ratio of Sn₄P₃. After milling for 30h, Sn₄P₃wires with large specific surface were obtained. It is worth noting that after doping with 5 wt.% Al powders, more quantity of Sn₄P₃ wires with multi-directional bending were observed, which would improve the application of phosphides due to the larger surface area. Furthermore, it was found that the sintering process would improve the formation of Sn₄P₃according to the increasing intensity of diffraction peaks. Meanwhile, the quantity of Sn₄P₃ wires was found to decrease, which might result from the merging behavior of powders during the sintering process.

Abstract: In order to reduce the variation of suspension parameters during wheel runout, andimprove the handling stability of the whole vehicle, a method for optimal design of Torsional beamsuspension structural parameters based on Multi-island genetic algorithm is proposed. Study on theMacpherson Front suspension of a car, based on the Euler's four-element method of multi-bodydynamics and the spatial analytic geometric transformation formula, the mathematical model ofTorsional beam suspension is derived in this paper, the reliability of the mathematical model isverified by the simulation analysis of the corresponding Adams model. On this basis, the degree ofsuspension performance affected by structure parameters is obtained by Sensitivity analysis. Finally,the optimization of suspension performance is realized by modifying the parameters by usingMulti-island genetic algorithm, which plays an important role in the stability and safety of thewhole vehicle.

Abstract: Application of radiation defects for lifetime control in contemporary SiC PiN diodes was investigated using the calibrated device simulator ATLAS from Silvaco, Inc. Recombination models accounting for the effect of deep levels introduced by the irradiation were set according to experimental results obtained by C-V and DLTS measurements performed on low-doped n-type SiC epilayers irradiated with 4.5 MeV electrons and 670 keV protons. Global (4.5 MeV electron irradiation) and local (700 keV proton irradiation) lifetime reduction was then applied on the 2A/10kV SiC PiN diode and the ON-state and reverse recovery characteristics were simulated and compared. Results show that the proton irradiation can substantially improve the trade‑off between the diode ON‑state and turn‑OFF losses. Compared to the electron irradiation, the local lifetime killing by protons allows achieving better trade-off and softer recovery curves.

Abstract: This paper explores the optimization cases for overcritical Organic Rankine Cycle (ORC) in various situations. First the ORC optimization in terms of working fluid selection is discussed. In this case, thermal efficiencies for 10 different working fluids have been calculated under certain temperature frames and the results are compared. Second, overcritical optimization case in terms of variation of hot temperature and evaporation pressure is presented. In this overcritical ORC case, the influence of evaporation pressure on ORC thermal efficiency is studied by conducting a case study of R234a, and first 1-D freedom optimization case is discussed within the variation of evaporation pressure. 2-D freedom optimization is also considered, in which the two independent variables, hot temperature and evaporation pressure, are both varied within certain boundaries. This study employs numerical method for this 2-D problem and it is also presented in detail in the case study.

Abstract: The three dimensional model of the bar bending mechanism was carried out by using the software Solidegde in this article,and then,import it into the multi-body dynamics simulation software Adams for the dynamic simulation and parameter optimization. Analysis results show that: The non-uniform stress phenomenon on the institutions must be effectively reduce under a appropriate damping ratio coefficient .

Abstract: The damper parameter of a concrete-filled steel tube arch bridge is optimized. Random Fourier spectrum based on physical model is used to synthesis the random time-domain excitation. Four evaluation functions have been constructed as optimization of the objective functions based on energy dissipation and structural control indexes. Comparing two energy evaluation function combinations and traditional control evaluation functions, the damper optimization parameters have been obtained. Result shows that: Optimized damper parameters of concrete-filled steel tubular arch bridge under various seismic waves have high damping effect. After introducing the energy dissipation indexes, evaluation functions avoided the extreme value disadvantages of the traditional target, the final optimization results could be more economical and practical.

Abstract: This study presents a soft computing based technique in the deposition parameters optimization of RF Magnetron Sputtering process. Particle Swarm Optimization (PSO) has been chosen due to its good performance in solving various optimization problems. The material used in this study was zinc oxide (ZnO) and there were four deposition parameters involved the optimization process. The deposition parameters were RF power, deposition time, oxygen flow rate and substrate temperature. The aim of the study was to obtain the optimal combination for the selected deposition parameters in order to produce the desirable ZnO thin film properties. In this study, the Desirability Function had been adapted as the fitness function for PSO. Desirability function is one of the commonly used statistical method for obtaining optimal process parameter design. The result from the PSO based optimization technique was then compared with actual laboratory result. Based on the observation made, the PSO based technique has been proven to be reliable and satisfactory in obtaining the optimal deposition parameters of ZnO thin film. It is expected that this soft computing based technique for optimizing the deposition parameters could reduce the trial and error method before the experiment is conducted in the fabrication process.