Mechanics of Solids最新文献

For an anisotropic layer with arbitrary elastic anisotropy, dispersion relations for harmonic plane Lamb waves are constructed, and an analysis of solutions for a symmetric fundamental mode at an infinitely small frequency (soliton-like waves) is performed. Dispersion equations for Lamb waves, including the corresponding limiting values, are obtained in explicit form.

In this paper, the principle of obtaining conditions for matching input data is formulated. A set of matching conditions is obtained, failure to fulfill which leads to large unavoidable errors in the corners of the rectangle. The problem is solved in analytical form using the method of universal fast expansions. The obtained approximate analytical solution is compared with the test one, the error in determining the plate deflection, torque and bending moments, shear forces and stress tensor components is investigated. It is found that when using a sixth-order boundary function and only one term in the cosines and one term in the sines in the Fourier series in universal fast expansions, the accuracy of the obtained solution significantly exceeds the accuracy of specifying the input parameters of the problem determined by the concept of a continuous medium. In this case, the approximate analytical solution can formally be considered exact.

To enhance the impact resistance and energy absorption capacity of traditional hexagonal honeycomb (THH) structures, a novel bionic progressive gradient hierarchical (BPGH) honeycomb structure is proposed herein through biomimetic design principles, while systematically considering the influence of hierarchical factors on structural performance. The energy absorption characteristics of the BPGH structure are systematically analyzed through finite element analysis and experimental testing. The results demonstrate that compared with traditional hexagonal honeycomb (THH) structures, the BPGH configuration exhibits significant advantages in reducing peak crash forces and enhancing energy absorption efficiency. Specifically, the BPGH structure demonstrates superior values in maximum crash force (MCF) and specific energy absorption (SEA) when benchmarked against THH counterparts. Moreover, BPGH configurations with higher hierarchical levels exhibit lower peak crash forces (PCF) and reduced load fluctuations, leading to a 23.6% improvement in energy absorption stability and a 17.4% increase in specific energy absorption capacity, thereby significantly enhancing overall energy absorption performance.

This study presents the Improved Modified Extended Tanh Function Method (IMETFM) as an advanced analytical approach to investigate the influence of laser pulse phenomena on thermo-elastic materials exhibiting temperature dependent properties within the framework of coupled thermoelasticity theory. Given the nonlinear nature of thermoelasticity, the research focuses on scenarios where thermal variations induce substantial changes in both the material’s structural form and intrinsic characteristics. Understanding these interactions is crucial for accurately modeling real-world applications, such as the distribution of thermal stresses in large-scale engineering structures, the impact of temperature fluctuations on material performance, and the intricate coupling between mechanical and thermal responses. By employing the proposed analytical method, a diverse set of exact wave solutions has been derived, incorporating multiple free parameters. These solutions include bright soliton solutions, as well as rational, exponential, and hyperbolic function-based solutions. To further elucidate the findings, graphical representations of key physical quantities are provided, suchprovided, such as temperature, displacement fields, and components, offering deeper insight into the underlying thermoelastic behavior and facilitating better interpretation of the results.

With the increasing severity of low-frequency noise and vibration issues, traditional vibration and noise reduction technologies often have limited effectiveness in the low-frequency range. This research proposes a new type of localized resonance periodic structure block (LRPB) and systematically investigates its bandgap characteristics and performance in vibration and acoustics, combining theoretical analysis and finite element simulations. First, based on local resonance theory, the bandgap characteristics of infinite periodic structures were calculated using the plane wave expansion method. Next, a computational model of finite periodic structures was established using COMSOL software, and the accuracy of the bandgap characteristics was verified. In addition, this research also explored the key factors affecting vibration transmission characteristics. The results show that the LRPB exhibits significant vibration attenuation within the bandgap frequency range. Particularly under lateral excitation, increasing the number of periodic units, the thickness-to-span ratio, and the cross-sectional dimensions significantly enhances the vibration reduction effect. Further acoustic performance analysis reveals that, compared to traditional concrete barrier, the LRPB demonstrates superior sound insulation performance in the low-frequency range. Notably, in the 0–200 Hz frequency range, it significantly increases sound transmission loss (STL). Finally, vibration and noise reduction studies on ground-based sound barriers indicate that the LRPB has a remarkable vibration and noise reduction effect in practical engineering applications, effectively improving the acoustic environment.

The article deals with the response of an infinite thermoelastic half-space model. An internal heat source of constant magnitude is acting in the half-space. This study sought to improve the comprehension of wave propagation in thermoelastic materials according to Classical theory of elasticity (CT) by developing precise wave solutions for the governing equations that take into consideration temperature-dependent material features. The analytical expressions of displacement and temperature field are obtained by Lame’s potential method and normal mode analysis technique. The work includes detailed graphical representations of crucial discoveries such as temperature distributions, stress components, and displacement components which provide amazing visual insights into the complex interactions that occur within thermo-elastic systems.

This study examines the dynamic behavior of functionally graded spherical shallow nanoshells with taking into acount the effects of porosity. Eringen’s nonlocal elasticity theory was utilized to adjust for the small-scale effects on the free vibration behaviors of the functionally graded spherical shallow nanoshells. The governing equations are derived from a higher-order shear deformation theory and Hamilton’s preincple. These equations are subsequently solved by Navier’s closed-form method to produce a reliable and accurate model. The present model’s accuracy and dependability are confirmed through in-depth case studies. This work is remarkable in that it presents a thorough understanding of the free vibration responses in functionally graded spherical shallow nanoshells, all while paying close attention to small-scale effects. The subsequent parameter study researches the impacts of some factors on the free vibration characteristics of functionally graded spherical shallow nanoshells, including aspect ratio, thickness ratio, graded index, and nonlocal parameter. This work advances the discipline by providing a unique viewpoint on structural dynamics at the nanoscale. This work is distinguished by the careful considering the impacts of the nonlocal parameter, which advances the understanding of these complex systems and opens up new avenues for future advancements in micro/nanostructure design, testing, analysis, and optimization.

This work presents a novel computational framework for analyzing cavitation phenomena triggered by environmental temperature and humidity in thermo-responsive elastomeric gels. We demonstrate that cavitation instabilities, originating from pre-existing defects, exhibit discontinuous cavity expansion under permeable boundary constraints in swollen gels. Through variational methods, constitutive equations are achieved based on equilibrium thermodynamics of elastomeric gels. Physics-constrained neural network with inverse transform sampling (ITS-PCNN) is developed to approximate the solution to the governing equation, which demonstrates superior stability and accuracy compared to conventional physics-informed neural networks (PINN), achieving consistently lower residual norms for both geometric and equilibrium equations. The ITS-PCNN framework enables comprehensive investigation of the coupling effects of temperature and humidity on cavitation behavior in thermo-responsive elastomeric gels. Our findings establish a robust computational platform for predicting cavitation responses under varying environmental conditions, advancing the design of responsive materials for biomedical and microfluidic applications.

The present research paper investigates the behavior dynamic of a wet bone represented as a crystal class 6 magnetic hollow cylinder. It expresses to solve the problem of the waves propagation concerning a possible function that fulfills partial differential equations whose solutions help derive the wave equation explicit solution. The mechanicaland Maxwell’s boundary circumstances match those of thestress of the lateral surface. The satisfaction of the boundary circumstancesmotivates dispersing the relationshipthatis resolved numerically. The wave frequencies are thus determined as the function of severalparameters. Theyagree well with the results of the literature. The frequencies are calculated using various magnetic field amplitude and porosity bone parameters for poroelastic bone. The results can contribute to the theoretical development of orthopedic research projects concerning poroelastic, long, cylindrical bones. The results obtained compared with the previous results obtained by others indicated to the strong effect for the magnetic field on the propagation waves via poroelastic bone. Theoretical results and invitro practical values recorded by a previously designed non-contacting magnetic field were compared.

This study investigates the reflection and propagation of thermoelastic plane waves in a nonlocal elastic solid with temperature-dependent material properties, using the Lord-Shulman thermoelasticity model and Eringen’s nonlocal elasticity theory. Three wave modes are identified: two coupled longitudinal waves and one shear wave, all of which exhibit dispersion and attenuation due to elastic nonlocality. The shear wave experiences a critical frequency, while the longitudinal waves face conditional critical frequencies. Reflection at a stress-free thermally insulated boundary is analyzed, and amplitude ratios of reflected waves are derived. Numerical results for copper-like materials reveal that nonlocality significantly influences all wave modes, while thermal effects impact only the longitudinal waves. Additionally, nonlocality reduces the shear wave speed compared to classical theory. Additionally, nonlocality reduces the shear wave speed compared to classical theory. The novelty of this work lies in the combined consideration of nonlocal elasticity, temperature-dependent moduli, and Lord-Shulman thermoelasticity, which has not been previously studied for reflection of thermoelastic waves at thermally insulated/isothermal boundaries. This approach provides a more accurate representation of wave behavior in microscale thermoelastic media with varying thermal environments.