Gnuplot Helper – a new Utility for gnuplot Graph Plotting Software

The gnuplot is a well known software for graph plotting in the field of science andengineering. It is a command based software originally built for Linuxenvironment, however now it’s available for other operating systems too. Thepresent review discusses overview of a utility software namely Gnuplot Helper tobe used with gnuplot. This utility can generate and run gnuplot scripts in GraphicalUser Interface mode very easily and can save the output as an image file which canbe used in research papers or other purposes. This paper also discusses how to usethe software.

Enhancing Adaptable Topological Wave Bandwidth in Piezoelectric Metamaterials via Circuitry and Lattice Symmetry Control

Recently, an electromechanical metamaterial with integrated resonant circuit elements was developed that enables on-demand tailoring of the operating frequency and interface routes for topological wave transmission. However, limitations to the operating frequency region still exist, and a full exploration of the adaptive characteristics of the topological electromechanical metamaterial has yet to be undertaken. To advance the state of the art, this study investigates the ability to enhance the range of operating frequencies for topological wave transmission in a piezoelectric metamaterial by the reconfiguration of lattice symmetries and connection of negative capacitance circuitry. In addition, the capability to modify the interface mode localization is analyzed. The plane wave expansion method is utilized to define a working frequency region for protected topological wave transmission by evaluating a local topological charge. Numerical simulations verify the existence of topologically protected interface modes and illuminate how the localization and shape of these modes can be altered via external circuit parameters. Results show that the reconfiguration of the lattice structure and connection to negative capacitance circuity enhances the operating frequency bandwidth and interface mode localization control, greatly expanding the adaptive metamaterial capabilities.

Method Prediction for the Environment of Vibration Structure in Consideration with Elastic Joint

In order to accurately and efficiently predict the environment of vibration structures with elastic joints, the BUSH equivalent elastic joints unit of MSC. Nastran software was used to deduce the natural frequencies of structures with elastic joints by using the Fixed Interface Mode Synthesis Method (FIMSM).An example structure with elastic joint is designed, and both FIMSM and traditional FEM are used to calculate the first 30 order natural frequencies of the example structure. The results show that, compared with FEM, the relative calculation error of FIMSM is within ±1.31%. Consequently, via using BUSH element to simulate the elastic joint, FIMSM possesses the ability to predict the Environment of Vibration Structure considering elastic joint precisely and efficiently.

Numerical factorization of a matrix-function with exponential factors in an anti-plane problem for a crack with process zone

In this paper, we consider an interface mode III crack with a process zone located in front of the fracture tip. The zone is described by imperfect transmission conditions. After application of the Fourier transform, the original problem is reduced to a vectorial Wiener–Hopf equation whose kernel contains oscillatory factors. We perform the factorization numerically using an iterative algorithm and discuss convergence of the method depending on the problem parameters. In the analysis of the solution, special attention is paid to its behaviour near both ends of the process zone. Qualitative analysis was performed to determine admissible values of the process zone's length for which equilibrium cracks exist. This article is part of the theme issue ‘Modelling of dynamic phenomena and localization in structured media (part 1)’.

Wave Dynamics in Reconfigurable Tristable Mechanical Metamaterials

We explore unique wave dynamics in a chain of tristable structures, inspired by multistable origami. We specifically focus on the frequency band structure of the chain, and conduct numerical and theoretical analysis. The band gap of the chain can be controlled by switching the stable state of each tristable structure. We also show that if two regions of the chain have different topological properties then wave localization can occur at the interface of the two regions. Interestingly, this interface mode is observed within the band gap. We demonstrate that the interface mode can be altered by leveraging the reconfigurable nature of the tristable structure. Our findings suggest a new strategy for controlling wave propagation in reconfigurable structures, which could be relevant for engineering applications such as energy harvesting.

Topological Phase Transition in a One-Dimensional Elastic String System

We show that topological interface mode can emerge in a one-dimensional elastic string system which consists of two periodic strings with different band topologies. To verify their topological features, Zak-phase of each band is calculated and reveals the condition of topological phase transition accordingly. Apart from that, the transmittance spectrum illustrates that topological interface mode arises when two topologically distinct structures are connected. The vibration profile further exhibits the non-trivial interface mode in the domain wall between two periodic string composites.