Ch. Zhang

Ch. Zhang
Universität Siegen

Prof. Dr.-Ing. habil. Dr. h.c.

About

712
Publications
91,231
Reads
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14,813
Citations
Introduction
Structural Mechanics, Computational Mechanics, Acoustic and elastic metamaterials, Wave propagation
Additional affiliations
January 2014 - present
Universität Siegen
Position
  • Professor
January 2014 - present
Universität Siegen
Position
  • Professor

Publications

Publications (712)
Article
Full-text available
By the stiffness matrix method based on the nonlocal elastic continuum theory, the transmission spectra of the transverse elastic waves propagating normally in nanoscaled periodic piezoelectric laminates with defects are investigated in detail in this paper. Defect is introduced by replacing a constituent layer or inserting another layer in a unit-...
Article
In this paper, the photo-thermoelastic wave propagation analysis in a semiconductor nanorod resonator under laser excitation employing the strain-gradient Moore–Gibson–Thompson (MGT) and Love–Bishop theories is presented, which is for the first time to the authors’ knowledge. The governing equations of the photo-thermoelastic wave propagation are d...
Article
Full-text available
Conventional two-dimensional (2D) re-entrant auxetic honeycomb is one of the earliest examples of auxetic metamaterials. Recently, plenty of 2D re-entrant honeycomb variants are developed to enhance their stiffness. However, the stiffness enhancement for most of the existing designs is generally obtained with compromising the conjugated auxeticity....
Article
Time fractional differential model is an effective tool to characterize anomalous diffusion phenomena in hydrology and environmental science. Efficient numerical method is necessary to overcome the bottleneck of expensive computational cost for real-world application. Therefore, this paper proposes a scale-dependent hybrid algorithm to numerically...
Article
This paper proposes a new method based on the polynomial expansions for structural uncertainty analysis. A generalized finite difference method (GFDM) based on the Taylor expansion is adopted to compute the structural responses, which has good adaptabilities to the analysis domains due to its meshless property. With the help of the polynomial chaos...
Article
Full-text available
A Lagrangian–Eulerian stabilized collocation method (LESCM) for the fluid–structure interaction problems involving free surface flow is presented in this work, in which the structure is modeled by a rigid body. This method is an evolution of the material point method and particle-in-cell methods which are based on the hybrid Lagrangian–Eulerian des...
Article
Representative of the advanced engineering designs, hierarchical structures have attracted particular attention in academia and engineering. This study proposed a novel design strategy to obtain hierarchical structures with three layers. The macroscopic layer contained the structures to be optimized, which were periodically fashioned by multi-phase...
Article
Stress concentration caused by reinforcements has very unfavorable effects on the metal matrix composites, which will inevitably induce localized strains and crack initiation. In this paper, an effective approach is presented to relieve stress concentrations near the reinforcements in metallic composites. The Ag-SnO2 contact materials with CuO addi...
Preprint
Study on artificial structured-materials to control waves is a lasting hot topic due to their unprecedented properties. However, the narrow working frequency range highly hinders their applications. In this work, a tunable zigzag metamaterial beam with a wider working frequency range is proposed through incorporation of springs and damping elements...
Article
In this paper, the general equations of plane strain problems are first summarized for three typical couple stress theories. Based on the constitutive relations, the general traction boundary integral equations (TBIEs) are then derived from the displacement BIEs (DBIEs) along with the explicit high-order fundamental solutions for the plane couple-s...
Article
In this paper, a novel design concept for active auto-adaptive metamaterial (AAAMM) plates is proposed based on an active auto-adaptive (AAA) control strategy guided by the particle swarm optimization (PSO) technique. The AAAMM plates consist of an elastic base plate and two periodic arrays of piezoelectric patches. The periodic piezoelectric patch...
Preprint
Full-text available
In this paper, a method based on the physics-informed neural networks (PINNs) is presented to model in-plane crack problems in the linear elastic fracture mechanics. Instead of forming a mesh, the PINNs is meshless and can be trained on batches of randomly sampled collocation points. In order to capture the theoretical singular behavior of the near...
Article
Full-text available
In this work, we propose a method to design subwavelength metasurfaces for flexural waves in thin plates based on sinusoidally-shaped phononic beam structures. In the proposed method, the effective bending stiffness of sinusoidally-shaped phononic beam structures is tuned, and the effective phase velocity of the flexural waves is modulated subseque...
Article
In this paper, a phononic crystal (PnC) Luneburg lens is designed for harvesting the mechanical energy of Rayleigh surface waves. The square-latticed PnC is formed by drilling holes periodically in an aluminum matrix. The PnC Luneburg lens for Rayleigh surface waves is constructed by spatially modulating the hole radius of each PnC unit-cell accord...
Article
In this study, we propose the three-dimensional (3D) phononic crystal-based coupled resonator waveguides (PnCCRWs) for the guidance of acoustic waves along complex routes. The proposed 3D PnC exhibits a complete acoustic band-gap. The point defect mode with a frequency in the band-gap is achieved via the introduction of a point defect into the perf...
Article
Sandwich structures (SSs) are widely deployed in engineering applications, such as for the low-frequency vibration or acoustic mitigation and isolation. However, it is challenging to enhance their low-frequency vibration mitigation and isolation performance while maintaining their multi-functionalities, such as lightweight, high bending stiffness,...
Article
This study proposes a new method for the topological design of hierarchical structures with high performance in thermal insulation. Firstly, a three-layer design strategy including macro-, meso- and micro-layers is presented. The macroscopic structures are formed by periodically arranged mesoscopic structures, whose topological configurations are d...
Article
Composite materials with multiple properties are important for a range of engineering applications. Hence, this study focuses on topological design of hierarchical materials with multiple performance in both thermal insulation and mechanics. First, a novel multi-objective optimization function is defined to find a solution from the Pareto frontier,...
Article
Most existing mixed-mode I/II delamination growth criteria are purely empirical or semi-empirical fitting functions of the experimental fracture toughness, which limit their wide range applications. In this work, a novel delamination growth criterion is proposed for mixed-mode I/II delamination predictions considering the significant R-curve effect...
Article
Unidirectional nonreciprocal wave propagation is an unprecedented phenomenon, which has attracted much research interest. Connecting a phononic crystal with an asymmetric structure to break the spatial inversion symmetry is a popular manner to realize this phenomenon using the wave mode transformation. In this paper, a new model is proposed based o...
Article
Purpose: Flexural wave propagation in non-homogeneous plates has wide engineering backgrounds, such as the out-of-plane vibration of the decks in buildings, and so on, and the corresponding research will provide some useful suggestions for the vibration control of the associated structures. Method: Taking the out-of-plane vibration of the basal pla...
Article
Unlike their electromagnetic and acoustic counterparts, elastic waves involve different wave modes. The interplay and the coupling among them increase the complexity of the problem while also offering a larger space for wave manipulation. Elastic bulk wave conversion in an elastic metamaterial has recently shown great promise in medical ultrasound...
Article
Full-text available
In this paper, we propose a kind of reflection-type broadband acoustic coding metasurfaces (BACMs), which are composed of two square helical channels and the connected air cavity at the end of the channels. This helical-cavity coupled structure is selected as a logical unit “1,” the pure air hole is set as a logical unit “0,” and the reflective pha...
Article
Full-text available
Unlike conventional metamaterials with a periodic array of identical resonators, rainbow metamaterials consist of an array of discrete resonators with a spatially varying parameter, yielding a wide attenuation band gap. In this research, a particular kind of gradient zigzag metamaterial beam with rainbow effects is proposed with the gradual height...
Article
Full-text available
The miniaturization of electronic devices is an important trend in the development of modern microelectronics information technology. However, when the size of the component or the material is reduced to the micro/nano scale, some size-dependent effects have to be taken into account. In this paper, the wave propagation in nano phononic crystals is...
Article
Due to their limited number of units but outstanding ability to control rather complex wave-propagation phenomena, acoustic coding metasurfaces (ACMs) as two-dimensional metamaterials show a stronger competitiveness in metamaterial applications. However, hindered by their narrow-band modulation capability, the previously reported ACMs do not exhibi...
Article
Full-text available
Metasurfaces, the ultrathin media with extraordinary wavefront modulation ability, have shown great promise for many potential applications. However, most of the existing metasurfaces are limited by narrow-band and strong dispersive modulation, which complicates their real-world applications, which usually require strict customized dispersion. To a...
Article
Full-text available
Inspired by the electronic demultiplexer, acoustic/elastic demultiplexers have received much attention in recent years. An acoustic/elastic demultiplexer can split one input wave signal into several output wave signals based on their frequencies. However, little to no work has been reported on the acoustic/elastic demultiplexers by considering the...
Article
Micro- and mesostructures of multiphase materials obtained from tomography and image acquisition are an ever more important database for simulation analyses. Huge data sets for reconstructed 3d volumes typically as voxel grids call for criteria and measures to find an affordable balance of accuracy and efficiency. The present work shows for a 3d me...
Article
Full-text available
Pre-stresses or axial loadings induced by deformations of adjacent structures, edge constraints or mounting inaccuracies and elastic supporting components attached to one side of the sandwich structures may affect the aerothermoelastic stability, which is an important subject in the design of supersonic aircraft. Therefore, the nonlinear flutter an...
Article
Full-text available
The coupling effect between the vibration of the electric components and the wave propagation is the critical factor that should be considered in the optimization on the layout of the electric components in the spacecrafts. Different from the case considered in our previous job, the layout of the electronic components on the spacecraft is always as...
Article
In this study, we design the 3D-printed phononic crystal (PnC) beam with the topological interface state for harvesting the mechanical energy of flexural waves. The PnC beam is formed by arranging periodic grooves on its surface. The PnC beam with either topologically trivial or non-trivial phase can be achieved via changing the distance between th...
Article
Digital building data models are increasingly employed in the design and construction planning of buildings, so that almost the entire planning process is covered with three-dimensional (3D) models. Starting with available detailed CAD data it is easy to generate 3D models for the design analysis. However, this comes with a price since the complexi...
Article
Full-text available
Flutter is a self-excited vibration under the interaction of the inertial force, aerodynamic force, and elastic force of the structure. After the flutter occurs, the aircraft structures will exhibit limit cycle oscillation, which will cause catastrophic accidents or fatigue damage to the structures. Therefore, it is of great theoretical and practic...
Article
Analogy with the standard anti-tri-chiral auxetic structure, a novel anti-tri-missing rib structure is proposed in this work. Finite element (FE) analyses (on one unit-cell) were carried out first to investigate the auxeticity and the underlying deformation mechanisms of the proposed structure with linear elastic base material. FE results show that...
Preprint
Phononic crystals (PCs) and metamaterials are artificially structured materials with the unprecedented property of the existence of complete stop-bands. However, the generally narrow width of the stop-bands in such materials severely limits their applicability. Here, a particular kind of gradient zigzag metamaterial beams exclusively with flat band...
Article
In this paper, the local radial basis function collocation method (LRBFCM) is presented to analyze 3D elastic problems of complex geometries. In particular, a real tooth domain built by cone beam computer tomography (CBCT) data is considered. The reconstruction process of a tooth shape, the choice of the local influence domain in the LRBFCM, as wel...
Article
Based on a consistent couple stress elasticity theory, a two-dimensional (2D) boundary element method (BEM) is developed to solve the boundary value problems in the couple stress elastic materials. The displacement boundary integral equations (BIEs) are applied to compute the mechanical quantities on the boundary. The integral representations for t...
Article
We study the electromechanical and piezotronic behaviors of a composite piezoelectric semiconductor cylindrical shell (CPCS), which consists of a piezoelectric dielectric layer and a non-piezoelectric semiconductor layer, under a uniform temperature loading. A simplified one-dimensional (1D) multi-field coupling model for the CPCS structure is esta...
Preprint
Full-text available
Phononic crystals (PCs) and metamaterials are artificially structured materials with the unprecedented property of the existence of complete stop-bands. However, the generally narrow width of the stop-bands in such materials severely limits their applicability. Here, a particular kind of gradient zigzag metamaterial beams exclusively with flat band...
Article
Full-text available
In this paper, the viscoelastic effect on the topologically protected interface states in two-dimensional (2D) solid phononic crystals (PnCs) is investigated. The valley topological interface states for the 2D in-plane and out-of-plane modes are generated on the interfaces between two PnCs with opposite topological phases. The complex band structur...
Preprint
In this study, we design the 3D-printed phononic crystal (PnC) beam with the topological interface state for harvesting the mechanical energy of flexural waves. The PnC beam is formed by arranging periodic grooves on its surface. The PnC beam with either topologically trivial or non-trivial phase can be achieved via changing the distance between th...
Article
A boundary element method (BEM) is implemented and applied to compute the band structures of phononic crystals taking account of three different kinds of imperfect interface layers. By using the Bloch theorem and the interface conditions the eigenvalue equations related to the wave vector are derived. The influences of the spring-interface model, m...
Article
This paper presents a novel localized collocation Trefftz method (LCTM) for heat conduction analysis in two kinds of heterogeneous materials (functionally graded materials and multi-medium materials) under temperature loading. In contrast to the conventional collocation Trefftz method (CTM), the proposed LCTM divides the whole domain into many sten...
Article
Efficient acoustic communication across the water-air interface remains a great challenge owing to the extreme acoustic impedance mismatch. Few present acoustic metamaterials can be constructed on the free air-water interface for enhancing the acoustic transmission because of the interface instability. Previous strategies overcoming this difficulty...
Article
A theoretical model and a finite element (FE) model are proposed to evaluate the effect of high temperature on the sound absorption performance of cylindrically perforated porous materials. The theoretical model is established by applying the double porosity theory, in which the perforated porous material is considered as a combination of the porou...
Article
In this paper, an effective theoretical method is developed and experimentally validated for investigating the vibration behaviors of the simply supported sandwich plates with a pyramidal truss core on elastic foundation. An adjustable sliding support frame that can adapt to variations in the plate length and width is designed to realize the simply...
Article
Background The elastic wave propagation characteristics, especially the local plus resonance phenomenon, affect the stability and the accuracy of the electronic components mounted on the spacecrafts significantly, which implies that the layout of the electronic components in the spacecrafts should be away from the plus resonance domains. Thus, cons...
Preprint
Full-text available
In this paper, a novel design concept for active self-adaptive metamaterial (ASAMM) plates is proposed based on an active self-adaptive (ASA) control strategy guided by the particle swarm optimization (PSO) technique. The ASAMM plates consist of an elastic base plate and two periodic arrays of piezoelectric patches. The periodic piezoelectric patch...
Article
In this paper, a meshless collocation method based on the generalized finite difference (GFD) method is employed for the band structure analysis of thermoelastic waves propagating in the cylindrical phononic crystal (PC). The Green-Naghdi (GN) theory of the generalized coupled thermoelasticity with energy dissipation and the Bloch's theorem are ado...
Article
A novel multiscale porous composite structure is proposed in this paper, which combines the advantages of two different micro-porous materials and distributed meso-pores to enhance the sound absorption performance. The proposed porous composite structure consists of a micro-porous material matrix with periodically distributed meso-pores, in which a...
Article
Full-text available
The paper presents an extended and advanced boundary integral equation method (BIEM) for simulating the elastic wave excitation and propagation in a layered piezoelectric phononic crystal with a strip-like crack or electrode. The method is based on the integral representation in terms of the Fourier transform of the Green's matrix for the whole pie...
Preprint
Full-text available
In this paper, we present an analysis of the guided circumferential elastic waves in soft EA tube actuators, which has potential applications in the in-situ non-destructive evaluation or online structural health monitoring (SHM) to detect structural defects or fatigue cracks in soft EA tube actuators and in the self-sensing of soft EA tube actuator...
Preprint
Material surface may have a remarkable effect on the mechanical behavior of magneto-electro-elastic (or multiferroic) structures at nano-scale. In this paper, a surface magneto-electro-elasticity theory (or effective boundary condition formulation), which governs the motion of the material surface of magneto-electro-elastic nano-plates, is establis...
Preprint
Surface effect responsible for some size-dependent characteristics can become distinctly important for piezoelectric nanomaterials with inherent large surface-to-volume ratio. In this paper, we investigate the surface effect on the free vibration behavior of a spherically isotropic piezoelectric nanosphere. Instead of directly using the well-known...
Preprint
Soft materials can be designed with a functionally graded (FG) property for specific applications. In this paper, we analyze the axisymmetric guided wave propagation in a pressurized FG elastomeric hollow cylinder. The cylinder is subjected to a combined action of axial pre-stretch and pressure difference applied to the inner and outer cylindrical...
Article
Full-text available
In this paper, we propose a novel porous metamaterial structure with an improved acoustic energy absorption performance at high-temperature and in the low-frequency range. In the proposed novel porous metamaterial structure, a porous material matrix containing periodically perforated cylindrical holes arranged in a triangular lattice pattern is app...
Article
Precise and target-oriented control of acoustic/elastic wave bandgaps in phononic crystals or acoustic metamaterials according to particular requirements is of both theoretical and practical importance. A very challenging and also interesting task is to tune the widths and the overall positions of the bandgaps of interest independently and arbitrar...
Preprint
As a representative of the lightweight designs, hierarchical structures are attracting widespread attentions in academia and engineering. This study proposes a novel two-stage design strategy to obtain hierarchical structures with three levels or layers. The macroscopic level is the structures to be optimized, which are periodically formed by mesos...
Article
Full-text available
This paper investigates the axisymmetric thermoelastic contact of a functionally graded material (FGM) coated half-space. A rigid insulated punch rotates on the surface of the FGM coating with a constant angular velocity. The frictional heating is generated within the contact region. The thermoelastic properties of the coating vary exponentially al...
Article
Based on the hyperbolic tangent shear deformation theory, free vibration and sound insulation of two different types of functionally graded (FG) honeycomb sandwich plates with negative Poisson’s ratio are studied in this paper. Using Hamilton’s principle, the vibration and vibro-acoustic coupling dynamic equations for FG honeycomb sandwich plates w...
Article
An acoustic labyrinthine porous metamaterial (ALPM) or the so-called acoustic labyrinthine metaporous surface is designed for the subwavelength sound absorption by perforating folded slits in a porous material matrix. A theoretical model is developed to study the sound absorption of the ALPM by combining the acoustic properties of two components: t...
Article
This paper presents a fracture analysis of ultra-thin coating/substrate structures with interface cracks. For this purpose, an advanced boundary element method (BEM) is adopted. To correctly describe the oscillatory displacement and stress fields near the interfacial crack-tip, a new set of novel special crack-tip elements are implemented. The comp...
Article
In this paper, we investigate the acoustic flatbands (FBs) in phononic crystal (PnC) defect lattices. The defects are introduced into a PnC composed of periodic rigid rods in the air background. Since the acoustic energy is highly confined inside the PnC defects, the interaction between the defects can be described by the tight-binding model. We co...
Article
This paper reports the first attempt to extend a novel localized boundary knot method to the 2D and 3D acoustic problems with complicated geometry. The solution of original partial differential equation with inhomogeneous term is firstly described as a sum of a particular solution and a homogeneous one. Secondly, the Chebyshev interpolation techniq...
Article
The effects of viscosity on the band-baps of two-dimensional (2D) viscoelastic phononic crystals are studied by the Dirichlet-to-Neumann (DtN) map method. The viscoelastic phononic crystals are composed of square or triangular lattices of elastic circular solid cylinders in a viscoelastic solid matrix. Time-harmonic anti-plane transverse (SH) waves...
Article
In this paper, a meshless Chebyshev collocation method (CCM) for the numerical solution of the eigenvalue problems of the Helmholtz equation is presented. The Chebyshev polynomials are employed for the efficient and accurate approximation of the eigenfunctions to ensure the pseudo-spectral convergence of the CCM. Two different approaches, namely th...
Article
The effects of the disordered local resonators on the vibration band-gap characteristics of the elastic metamaterial multi-span beams are investigated and validated by the vibration experiments. Compared with the complete periodic elastic metamaterial multi-span beams, it is demonstrated that the disordered periodic ones can broaden the band-gaps a...
Article
The lowest order shear horizontal wave (SH0 wave) is of great importance in structural health monitoring (SHM) and nondestructive testing (NDT), since it is the only non-dispersive guided wave mode in elastic plates. However, SH0 wave is less used than Lamb waves in the past decades, which is mainly attributed to the fact that controllable excitati...
Article
Pentamode metamaterials (PMs), a kind of metafluids composed of complex solid medium, have shown enormous potential for both elastic wave and underwater acoustic wave manipulation. However, due to the lack of thorough understanding of the formation mechanism, most reported artificial and empirical PMs share very similar topological features, thus d...
Preprint
Full-text available
Micro- and mesostructures of multiphase materials obtained from tomography and image acquisition are an ever more important database for simulation analyses. Huge data sets for reconstructed 3d volumes typically as voxel grids call for criteria and measures to find an affordable balance of accuracy and efficiency. The present work shows for a 3d me...