Finite Element Calculation of the Polymer Stamp Material Redistribution under Restrictions on Fatigue Life

The numerical method of stamp topological optimization taking into account fatigue strength is presented in the work. It is proposed to take into account the restrictions on the stress state in accordance with the curve of the dependence of the maximum stresses on the number of loading cycles in the ESO topological optimization method. An approach to the selection of the evolutionary coefficient with a step-by-step increase in the rejection coefficient is proposed when constructing an iterative scheme for the rejection of elements by the method of topological optimization. The calculation of the stamp optimal topology with a decrease in volume due to the removal and redistribution of material was carried out in the study. The new geometric model of the optimal topology stamp is based on the predicted distribution of elements with a minimum stress level. The verification calculation of the stress state of the stamp of optimal topology with an assessment of fatigue strength was carried out in the work. The numerical calculation was carried out using the finite element method in the Ansys software package. The minimized stamp volume decreased by 35% according to the calculation results. The results of the study can be further applied in the development of topological optimization methods and in the design of stamping tools of optimal topology.

Bacteria Foraging Algorithm for Optimal Topology Construction in Wireless Sensor Networks

Topology control is a significant method to reduce energy consumption and prolong the network lifetime. Connected Dominated Sets (CDS) are the emerging technologies to construct the energy- efficient optimal topology. Traditional topology construction algorithms are not utilized suitable optimization techniques for finding the optimum location of the active nodes in the networks. In this paper, Bacteria Foraging Algorithm (BFA) identifies the optimal location for active nodes to form the virtual backbone of the network. Residual energy and network connectivity are considered to evaluate the fitness function. The performance of the BFA is compared with other algorithms namely A3, A1, Genetic Algorithm (GA), and Gravitational Search Algorithm (GSA) algorithms for considering the performance metrics of the active nodes, residual energy, and connected sensing area coverage. Simulation results show that the proposed methodology performs well for reducing energy consumption and improving the connected sensing coverage area in the wireless sensor network.

Optimizing the Design of Surface-Acoustic-Wave Ring Resonator by Changing the Interdigitated Transducer Topology

Introduction. Previous works considered the frequency characteristics and methods for fixing sensitive elements in the form of a wave ring resonator on surface acoustic waves in a housing made of various materials, as well as the influence of external factors on sensitive elements. It was found that the passband in such a case is sufficiently wide, which can affect adversely signal detection when measuring acceleration using the sensitive element under development. Therefore, it has become relevant to reduce the sensitive element’s bandwidth by changing the design of the interdigitated transducer (IDT).Aim. To demonstrate an optimal topology for an IDT with a low bandwidth, leading to improved signal detection when acceleration affects the sensitive element.Materials and methods. The finite element method and mathematical processing in AutoCAD and in COMSOL Multiphysics.Results. Nine topologies of IDT are proposed. All these types were investigated using the COMSOL Multiphysics software on lithium niobate substrates, which material acts as a sensitive element. The frequency characteristics are presented. The data obtained allowed an optimal design of the ring resonator to be proposed: an IDT with rectangular pins without selective withdrawal.Conclusion. Self-generation in a ring resonator can be performed by withdrawing no more than one pair of IDTs for 10 or more periods. In this case, the withdrawal of IDTs should be uniform. With an increase in the number of IDT withdrawals, the geometry of the ring resonator is violated, and the wave leaves the structure. The presence of a shared bus keeps the surface acoustic wave inside the IDT structure, and the narrowing of the periods towards the inner part of the structure makes it possible to improve the frequency characteristics of the ring resonator on surface acoustic waves.

Parametric analysis of topologically optimized mechanical member considering dynamic loading

The optimal topology and its performance in dynamic loading situations result in discontinue function corresponding to the input factors such as volume fraction, thickness, material property, and loading conditions. In a realist scenario, the performance prediction becomes erroneous and challenging for the components under dynamic loading conditions with uncertainties. The conventional closed-form deterministic approaches are complicated for these problems. Here, a method is presented to establish the relative influence and function relationship of the input factors with the performance values, including controllable and non-controllable uncertainties. The design of experiment approach is used to apply full factorial design with Taguchi’s orthogonal array; performances of the optimal topologies are considered responses. The non-uniform topology generation method is applied based on the deflection threshold value to generate topologies for dynamic conditions. A dynamic model of the manipulator-link is developed to apply boundary conditions and provide performance values: compliance, deflection, Stress, and energy consumption values. Statistical techniques such as the analysis-of-mean (ANOM), analysis-of-variance (ANOVA), signal-to-noise-ratio (SNR), and mean performance values are employed to observe the significance of input factors and generate equivalent preformation relation. From ANOM and ANOVA, all input parameters show mutual interaction; force is observed as the most significant factor. From SNR values, experimental combination number 9,9,6,1 is observed as the most robust for compliance (21.13), deflection (43.93), Stress (−16.64), and energy consumption (12.05). Similarly, at the same combinations, the mean performance values are minimum and coefficient of determination (R2) percentages of the model are 94.64%, 96.93%, 73.69%, and 95.14%.

Novel Step-Up Topologies of Zigzag Autotransformer

Zigzag autotransformer is widely used in multi-pulse rectifier system. However, the traditional zigzag autotransformer does not have the step-up function. Meanwhile, by improving the zigzag autotransformer structure, the output voltage can be increased without additional auxiliary components. Therefore, based on the 12 pulse rectifier system, this paper analyzes and designs three zigzag autotransformer step-up topologies, establishes the corresponding mathematical topology, studies the relationship between the transformation ratio and system main parameters, and deduces the step-up range of the three topologies. When the transformation ratio is greater than or equal to 1.0353 and less than 2.0705 and when the transformation ratio is greater than or equal to 2.0705, the equivalent capacity of the three topologies are compared. Based on the comparison, the optimal topology is obtained in different cases. Finally, according to the theoretical analysis, the simulation parameters are set, the simulation circuit is built, and the results are analyzed combined with corresponding mathematical topologies.

Topology Control for Resource Management in Microwave Backhaul Networks

<p>Microwave backhaul networks are the dominant technology used to connect together access and core networks for their flexibility and cost-effectiveness in deployment. Unfortunately, microwave backhaul networks are susceptible to interference and are statically managed leading to poor Quality of Service (QoS) in the form of high delays and loss as well as being inefficient on energy. The use of Software Defined Networking (SDN) is proposed to address these problems by dynamically managing resources to work around the interference and remove static allocations. Two new algorithms, CUT and OptiCUT were designed to compute an optimal topology, to minimise loss and delay while at the same time reducing power consumption.</p>

Topology Control for Resource Management in Microwave Backhaul Networks

<p>Microwave backhaul networks are the dominant technology used to connect together access and core networks for their flexibility and cost-effectiveness in deployment. Unfortunately, microwave backhaul networks are susceptible to interference and are statically managed leading to poor Quality of Service (QoS) in the form of high delays and loss as well as being inefficient on energy. The use of Software Defined Networking (SDN) is proposed to address these problems by dynamically managing resources to work around the interference and remove static allocations. Two new algorithms, CUT and OptiCUT were designed to compute an optimal topology, to minimise loss and delay while at the same time reducing power consumption.</p>

Structural Analysis And Topology Optimization Design For Bandwidth Extension of Magnetoelectric Seismometer

Magnetoelectric seismometers can measure earthquake information and play an important role in earthquake monitoring. Aiming at the wider effective frequency bandwidth of magnetoelectric seismometers, a novel seismometer based on topology optimization structural pendulum is reported. The topology optimization of leaf spring structure in magnetoelectric seismometer is designed, the natural frequency and spurious frequency characteristics of the novel seismometer are analyzed. Based on variable density theory, the Solid Isotropic Material with Penalization (SIMP) model of the seismometer is established, and the Method of Moving Asymmetric (MMA) is adopted to obtain the optimal topology structure. The finite element analysis using ANSYS shows that novel seismometer after topology optimization structure is characteristic with lower natural frequency and higher spurious frequency than that of before optimization seismometer. The real vibration experimental results indicate that after topology optimization, the effective frequency bandwidth of seismometer is increased by 55.50%, improving from [1s, 51Hz] to [4s, 78Hz].

A Multilevel Inverter Topology Using Diode Half-Bridge Circuit with Reduced Power Component

This paper presents a new multilevel converter with a reduced number of power components for medium voltage applications. Both symmetric and asymmetric structures of the presented multilevel converter are proposed. The symmetric topology requires equal dc source values, whereas the asymmetric topology uses minimum switch count. However, both structures suffer from high blocking voltage across the switches. To reduce the blocking voltage on switches, an optimal topology is presented and analyzed for the selection of the minimum number of switches and dc sources, while maintaining a low blocking voltage across the switches. A comparative analysis with recently published topologies was performed. The simulation results, as well as the comparative analysis, validated the robustness and effectiveness of the proposed topology in terms of the reduced power loss, lowered number of components, and cost. Furthermore, in addition to the simulation results, the performance of the proposed topology was verified using experimental results of 9, 17, and 25 levels.

Topological Optimization of a Complex Shape Forming Stamp

The scientific research is devoted to the mathematical modeling of the optimal topology of stamps with a complex forming surface. Topological optimization is based on the SIMP method by creating a field of pseudo-densities and minimizing the pliability of the structure under the influence of load. When setting the problem, it is proposed to take into account the fatigue strength of polymers, taking into account the restrictions on the stress state. According to the results of the calculation in the ANSYS software package, an optimal redistribution of the stamp material and a reduction in volume due to the removal of elements that have little effect on the rigidity of the structure is obtained. The results of the study can be further applied in the field of hot and cold stamping by creating stamping tools of minimal volume.