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Various generations of scholars have proposed many material removal models for grinding processing. However, the stress conditions of the free surface and regular surface are different. The free-form models will encounter problems in practical application. To refine the stress distribution in the contact area during grinding, it is necessary to construct the elastic contact model for the workpiece profile. This paper uses dimensional reduction to introduce the double curvatures to approximate the varying curvatures of the free surface. So, the conclusions of classical elastic Hertz contacting theory can be applied to the model. We use differential thought to deduce the relation between the normal force and the maximum deformation depth of the contact region. Then, we obtain the boundary of the contact region. After dimensional reduction by Winkler theory, we propose the normal equivalent spring potential energy correction error terms. They compensate for the local stress based on the relationship between stress and deformation of continuous media. According to the boundary of the contact region obtained above, we carry out the differential stress distribution. This accounts for the dispersion effect of the convex surface on the force. Using stress-indicating film to show the local stress distribution, the results revealed that the stress distribution was consistent with that of the simulated contact stress distribution. The error was controlled within 0.078MPa. To verify the practicality of the contact model in grinding experiments, we derived the theoretical grinding depth by combining the Hammann linear grinding model. This paper compares the experimental results with the model results. It demonstrates the proposed algorithm's superior adaptability and practical application ability to the free surface. [ABSTRACT FROM AUTHOR]

Purpose: This paper presents the approximate limit pressure solution for shape-imperfect and through-wall circumferential cracked (TWCC) 90° pipe bends at the intrados region. Finite element (FE) limit analysis was used to estimate the limit pressure by considering the small geometrical change effects. Design/methodology/approach: Three-dimensional (3D) geometric linear FE methodology was implemented to investigate the limit pressure of structurally deformed TWCC 90° pipe bends. The material considered in the analysis is elastic perfectly plastic (EPP). The limit pressure of TWCC shape-distorted pipe bends was predicted from the corresponding internal pressure when von-Mises stress was equal to or just exceeded the material's yield strength for all the models. The theoretical solution which was published in the literature was used to evaluate the current FE approach. Findings: Ovality Co and TWCC at the intrados region caused a considerable impact on pipe bends, while the thinning? Ct produced a negligible effect and hence was not included in the analysis. With the combined effect, the bend portion of pipe bend experiences substantial influence, and the TWCC effect consequently increases with 45o, 60o and 90o crack angles and decreases the limit pressure of pipe bends. An improved closed-form empirical limit pressure solution was proposed for TWCC shape-distorted pipe bends at the intrados region. Originality/value: In the limit pressure analysis of 90° pipe bends, the implications of structural irregularities (ovality and thinning) and TWCC have not been examined and reported. [ABSTRACT FROM AUTHOR]

This paper establishes the exact second-order stiffness matrix of axial-loaded beam–columns on Winkler foundation. This Winkler foundation model has been widely used in engineering applications. The equilibrium analysis of an axial-loaded beam–column on Winkler foundation is conducted, and the element flexural deformations and forces are solved exactly from the governing differential equation. Two dimensionless factors for the axial force and foundation spring stiffness are defined, respectively. The exact second-order element stiffness matrix of the axial-loaded beam–column on Winkler foundation is then formulated, showing the relationship between the element-end deformations (translation and rotation angle) and the corresponding forces (shear force and bending moment). Such an exact second-order stiffness matrix may be used for the buckling and second-order solutions with allowance for the use of one element per member for the exact solution. The classical buckling problem of axial-loaded beam–columns on Winkler foundation with typical element-end boundary conditions is then analyzed by the developed matrix stiffness method. By comparing with classical buckling criterion expressions of axial-loaded beam–columns on Winkler foundation with various boundary conditions, it is demonstrated that the derived exact second-order stiffness matrix can be used to obtain the exact buckling solutions systematically. [ABSTRACT FROM AUTHOR]

To address the conflict between pressure relief and support effectiveness caused by large-diameter boreholes in roadway surrounding rock, this paper proposes a method involving variable-diameter boreholes for pressure relief and energy dissipation. With a typical rock burst coal mine as the engineering context, the study establishes a mechanical model for variable-diameter boreholes through theoretical analysis to examine the elastic stress distribution around boreholes within the coal body. Physical similarity simulation tests are conducted to investigate the influence of conventional borehole and variable diameter borehole on the transmission pattern of dynamic load stress waves. Furthermore, numerical simulations are employed to explore the effects of reaming diameter, depth, and spacing on pressure relief, energy dissipation, and attenuation of dynamic stress wave transmission in roadway surrounding rock. The results demonstrate that stress within the coal surrounding the variable-diameter borehole correlates with the borehole radius, lateral pressure coefficient, and distance from the point to the borehole center, the extent of the plastic zone is influenced by borehole diameter, spacing, and depth. Increased diameter, reduced spacing, and greater depth of deep reaming holes exacerbate the transfer of stress concentration from the surrounding rock of the roadway to the deeper regions, facilitating the formation of stress double peak areas. Moreover, the variable diameter position should be within the original stress peak position of the surrounding rock in the roadway, with deep reaming passing through the stress concentration area for optimal results. This study offers guidance on the prevention and control technology for rock bursts in deep coal mining operations. [ABSTRACT FROM AUTHOR]

Results of the study of symmetrical facing wrinkling of compressed rectangular composite sandwich plates with orthotropic faces and core are presented in the paper. Two parallel edges of the plate facings are simply supported, one edge is clamped, and another edge is free (SSCF). The wrinkling problem is solved using the Ritz method in which the total energy functional of plate faces and core is obtained based on the original model, considering nonlinear variation of the transverse displacement of the core material from the value of facing's deflection to zero. Application of the Ritz method yields formulas for the calculation of critical compressive load. The critical load is found using a minimization with respect to the parameter of the wrinkling waves evolution and the parameter characterizing the rate of fading of the transverse displacement. Based on the derived formulas, the effects of facing and core thicknesses, and modulus elasticity of core material on the critical wrinkling load are studied. The results of calculations are verified using a finite element analysis. It is shown that the value of critical load calculated based on the proposed model is more accurate compared to that calculated using the Winkler-Pasternak model, particularly for the sandwich plates with thin faces and thick core. [ABSTRACT FROM AUTHOR]

To accurately capture crack trajectory and failure morphology with continuum mesoscopic model-based methods in three-dimensional space, conventional global uniform refinement schemes may incur significant computational cost. This paper first presents a three-dimensional structured mesh refinement strategy to achieve the hierarchical discretization for the focused region. To deal with the mismatching problem caused by different-sized meshes, a coupling interface technique based on the discontinuous Galerkin framework is proposed. The validity and advantages of the present strategy are first verified by a benchmark example for elastic analysis. By strongly collaborating with the statistical meso-damage smear method, we further simulate the spatial crack growth (including a through-thickness crack, an embedded crack, and a surface crack) and the local failure process of a D-shaped tunnel. Great agreements between the simulation results and the available experiment or numerical reference results demonstrate that the present method can effectively simulate the rock fracturing process as well as save considerable computational time and memory storage. Highlights: A three-dimensional structured mesh refinement strategy is presented for the geometric and scale restrictions of rock meso-fracturing simulations. An effective coupling interface technique is introduced to accurately capture the interface effects and couple different-sized meshes. Different crack configurations, including a through-thickness crack, an embedded crack, and a surface crack are simulated. The present method can achieve an ideal trade-off between accuracy and computing effort. [ABSTRACT FROM AUTHOR]

Stern tube slide bearing of the shaft line of the ship’s propulsion system causes losses during operation. Friction and material wear of the tribosystem occur. One of the reasons is the different navigating regimes of the ship, which have an influence on the formation of the velocity field on the ship’s propeller. The variable velocity field defines the magnitude and the position of the thrust force. The methodology presented in this paper is based on the fact of the existence of the eccentricity of the thrust force, i.e. loads due to the action of the moment of the eccentric thrust force. Due to the changing position of the thrust force, the curvature of the elastic line of the sleeve inside the stern tube bearing, which is mostly spatial, changes. Spatial elastic line of the sleeve has an influence on the working area of the slide bearing. Therefore, the importance of a sufficient thickness of the lubricant layer for lubrication in relation to these changes was highlighted. In this paper, this is the initial criterion for the selection of materials and lubricants of the stern tube bearing. An equally important criterion would be to define the possible harmful impact of lubricant leakage with particles of bearing bush material on the ecosystem. In order to facilitate the whole process, the simplified analytical model is presented, which can be used in the initial stage of stern tube bearing selection. Such a model allows a simpler analysis of the influence of the elastic line on the condition of the stern tube bearing due to the loading by the weight of the ship’s propeller and by the moment of the eccentric thrust force. The procedure for the initial selection of the stern tube bearing created by this methodological approach could have its practical application. For this reason, the paper analyzed different navigating regimes and their influence on the working area of the stern tube slide bearing. The obtained results can be useful in the selection of materials and lubricants for the stern tube bearing tribosystem. [ABSTRACT FROM AUTHOR]

In the process of designing a marine propeller, hydroelasticity effects are neglected in most cases, due to the negligible influence of the blade's deformation on its hydrodynamic characteristics. However, there are cases where the impact of hydroelasticity is crucial, for example in the case of high skew-back propellers or heavy-loaded composite propellers. Furthermore, the importance of composite propellers is growing due to their wide range of application, for instance in naval ships and unmanned vehicles. Although structural models and two-way fluid-structure interactions are implemented in most commercial CFD solvers, their relevance to the design process is severely limited due to the high computational cost for a single iteration. An effective solution would therefore be to implement a two-way fluid-structure interaction model in the lifting surface software, which is commonly accepted as a design tool due to its relatively low computational time and its applicability to multi-criteria optimisation. This paper presents the results of hydrodynamic analyses of an elastic propeller carried out using in-house software based on the lifting surface flow model, and extended with the FEM model for the blade structure. The results are compared with experimental measurements and computational analyses with the commercial RANS solver STAR-CCM+. [ABSTRACT FROM AUTHOR]

This paper introduces a conceptual framework for finite element analysis of generalized Maxwell viscoelastic materials based on the initial stress approach. The proposed method facilitates the explicit and convenient determination of mechanical parameters for viscoelastic materials by directly utilizing relaxation test data. Each time step's viscoelastic relaxation stress is treated as the initial stress, and a recursive calculation formula for the material's initial stress is established, relying solely on the relaxation stress and strain from the previous time step. Based on this, the study outlines the computational steps for initial-stress-based finite element analysis of elastic materials. The proposed algorithm's accuracy and efficiency are validated through a classical one-dimensional axial rod example. Results demonstrate that the introduced initial stress-type finite element analysis maintains the stiffness matrix equal to the initial stiffness matrix throughout the calculation process, significantly enhancing the efficiency of finite element analysis for viscoelastic materials while reducing the computational resource required. The conceptual framework improves the efficiency and accuracy of analyzing the mechanical parameters of viscoelastic materials using relaxation test data. [ABSTRACT FROM AUTHOR]

Multiphysics models were used to simulate the deformational characteristics experienced by paper under metering blades. Paper is found to slip microscopically at the backing roll interface and subsequently buckle either side of the blade during metering operations. Micro-slippage of the paper at the interface is a linear function of the separation height incurred during buckling. The effects of altering the static coefficient of friction as well as the properties of the backing roll material are studied. Increasing the coefficient of static friction reduces the extent of buckling while a non-linear relationship is found to arise on increasing the elastic modulus of the backing roll material. The mechanisms involved in micro-buckling deformation are explicated herein. [Copyright &y& Elsevier]

The study of multibody systems with elastic elements involves at the moment the reevaluation of the classical methods of analysis offered by analytical mechanics. Modeling this system with the finite element method requires obtaining the motion equation for an element in the circumstances imposed by a multibody system. The paper aims to present the main analysis methods used by researchers, to make a comparative analysis, and to show the advantages or disadvantages offered by different methods. For the presentation of the main methods (namely Lagrange's equations, Gibbs–Appell's equations, Maggi's formalism, Kane's equations, and Hamilton's equations) a unified notation is used. The paper provides a critical evaluation of the studied applications that involved some of these methods, highlighting the reason why it was decided to use them. Also, the paper identifies potential research areas to explore. [ABSTRACT FROM AUTHOR]

With the new architectural trend of designing flat slab floors resting on internal columns, a need arises for an accurate bending solution of thin plates internally supported by flexible column supports that considers all the flexibility parameters of the internal supports (deflection and slopes). This paper presents a boundary point method solution for bending of thin Kirchhoff plates resting on flexible internal column supports. The proposed method is valid for irregular plate shapes and layouts of the internal column supports as well as all possible plate's boundary conditions. The supports are modeled using their real patched areas and the equilibrium of the plate–support interaction involves three generalized internal forces: a force normal to the patched area and two bending moments about the two principal axes of the patched area. The three forces are introduced to the plate in terms of stresses over the patched area by dividing each support into a group of cells. The compatibility condition of the deflection is applied at the center of each cell, while the slopes conditions are applied at the center of each support. The paper is concluded with two application examples to illustrate the accuracy and efficiency of the proposed method. [ABSTRACT FROM AUTHOR]

This paper presents a new accurate method to compute the mechanical response of pavement structures using an Artificial Neural Network (ANN) model coupled with Multi-Layer Elastic Analysis (MLEA). The ANN model is used to improve the numerical integration of the response function used in the MLEA method. It requires four inputs: total pavement thickness, the diameter of the contact area, radial distance, and depth of the response point; and it was trained on one million hypothetical pavement structures. The developed method has been validated by a comparative analysis against boundary conditions, finite element analysis, and available MLEA solutions using various hypothetical pavement structures. The results demonstrate that the developed solution gives excellent response in the vicinity of the pavement surface together with a significant improvement in computational efficiency. [ABSTRACT FROM AUTHOR]

This paper presents a novel plasticity-based formulation for three-dimensional (3D) topology optimization of continuum structures. The proposed formulation addresses the optimization problem by combining mixed rigid-plastic analysis with density-based topology optimization, resulting in a volume minimization approach. Unlike conventional stress-constrained topology optimization methods that rely on linear elastic structural analysis, our developed formulation focuses on enhancing the loading capacity of the designed structures based on the plastic limit theory, leading to more cost-effective designs. To improve computational efficiency, we employ the smoothed finite element technique in our proposed method, enabling the utilization of linear tetrahedral elements for 3D mesh refinement. Moreover, the final formulation of our developed method can be efficiently solved using the advanced primal–dual interior point method, eliminating the need for a separate nonlinear finite element structural analysis. Numerical examples are presented to demonstrate the effectiveness of the proposed approach in offering enhanced design possibilities for continuum structures. [ABSTRACT FROM AUTHOR]

Resonant ultrasound spectroscopy (RUS) is a nondestructive technique, and one of its applications is to determine the elastic constants of a solid by measuring its free-vibration resonant frequencies. For dissipative materials, the vibration spectrum peaks are broad and strongly overlapped, and in some cases, the resonant frequencies extracted by a linear prediction filter are considered to be false positive frequencies that cannot be paired with theoretical resonant frequencies. The inverse identification of elastic constants is also seriously influenced when these false positive frequencies are wrongly paired with theoretical resonant frequencies. In this paper, a new selection index and an extraction process for RUS resonant frequencies are studied to discard false positive frequencies. The change in the relative error between the theoretical and extracted frequencies was employed to update the traditional frequency selection index. An extraction process was proposed by combining a trial-and-error method and a Bayesian method. A bone-mimicking material (quality factor, Q ≈ 30) and the simulated resonant spectra were adopted to validate the proposed method. The performance of identifying false positive frequencies was effectively improved by using the new selection index. Moreover, the proposed process can be applied to enhance the pairing and estimation accuracy for RUS. Calculations of the elastic constants for distinct specimens presented good consistency. The new method proposed in this paper provides a better analysis of the elastic constants in highly dissipative materials and can help to extend the application range of RUS. [ABSTRACT FROM AUTHOR]

This is the second paper of a trilogy intended by the authors in what concerns a unified approach to the stability of thermoelastic arched beams of Bresse type under Fourier's law. Differently of the first one, where the thermal couplings are regarded on the axial and bending displacements, here the thermal couplings are taken over the shear and bending forces. Such thermal effects still result in a new prototype of partially damped Bresse system whose stability results demand a proper approach. Combining a novel path of local estimates by means of the resolvent equation along with a control-observability analysis developed for elastic non-homogeneous systems of Bresse type proposed in trilogy's first paper, we are able to provide a unified methodology of the asymptotic stability results, by proving the pattern of them with respect to boundary conditions and the action of temperature couplings, which is in compliance with our previous and present goal. [ABSTRACT FROM AUTHOR]

The research hypothesis states that the impregnation of the honeycomb paper core of lightweight sandwich panels with modified starch, sodium silicate and epoxy resin (LiquidWood®) resin has a significant effect on its elastic properties. In this study, a recycled paper was used in three thicknesses, seven types of cell shapes, including two after numerical optimization and three types of impregnating agents. The method of digital image analysis determined the elastic constants of manufactured paper cores, which were subjected to axial compression in two directions. Based on the experimental results, elastic constants of the cores were calculated and compared with the results of numerical calculations. It has been shown that each of the impregnating solutions used improved the stiffness of the paper core. The best results were obtained for LiquidWood® epoxy resin and modified starch. An important parameter of cell geometry affecting their rigidity is the angle of the cell wall φ, as well as the arrangement of the common cell wall in relation to the direction of load. The numerical models developed were positively verified. [ABSTRACT FROM AUTHOR]

SiC/SiC composites are candidates of interest for fuel cladding applications in pressurized light-water reactors. In this study, fuel cladding tubes were made by filament winding and the matrix was deposited by CVI (Chemical Vapour Infiltration), which results in surface irregularities and waviness defects. This paper examines the influence of grinding steps on the mechanical behavior of tube specimens. Different depths of inner and outer surface grinding are carried out from a reference grade. Cyclic tensile tests are then performed. Elastic behavior analysis shows that the machining of tubes does not cause pre-damage. Analysis of unload-reload cycles indicates that the internal slippage does not depend on the seal coat thickness and that the surface quality weakly influences damage in the loading direction. Damage in the shear plane and ultimate failure strength strongly depend on the inner seal coat thickness. [ABSTRACT FROM AUTHOR]

This paper investigates the effective elastic constants of the perforated fibre-reinforcement damping membrane, taking into account the variations in perforation array and ply orientation angle using the homogenization method and the off-axis stress-strain relation. The equations for the free vibration of the composite beam with multi-layer perforated fibre-reinforcement damping membranes are derived using the first-order shear deformation theory and the Hamilton principle. These equations are then solved using the Navier method. The novelty of this paper lies in the achievement of an effective elastic constants model and vibration analysis for the multi-layer composite beam under simply supported boundary conditions. The calculated results are then compared with experimental values and finite element results to validate the theoretical model and method. Furthermore, the paper explores the graphical variation of mechanical performance with system parameters, providing a theoretical foundation for future researchers in the composite field. • Analysis of effective elastic constant using homogenization method. • Free vibration response of a multi-layer perforated damping beam is studied. • The fibre angle strongly affects the equivalent elastic constant of perforated beam. • Assessed for mechanical analysis of perforated beam. [ABSTRACT FROM AUTHOR]

The paper develops a stiffness reduction factor to be used in geometric nonlinear beam-element type elastic analysis of cold-formed steel structures. The factor accounts for the reduction in flexural and warping torsion rigidities resulting from local and distortional buckling as well as residual stresses, particular to cold-formed steel structures. The purpose of applying the factor is to accurately account for the geometric second order effects when predicting the internal distributions of moments of cold-formed steel structural frames. The stiffness reduction factor arising from local and distortional buckling is first determined followed by the stiffness reduction factor caused by residual stresses. Subsequently, the two effects are combined in a single expression, which is a format suitable for incorporation in the North American specification for cold-formed steel structures, AISI-S100. [ABSTRACT FROM AUTHOR]

This paper presents a thorough first-principles investigation of the physical attributes of the double perovskite (DP) oxide, Sr2ScBiO6. The calculated lattice constant and the bond lengths adequately reflect the experimental data. In addition, the mBJ exchange potential analysis classified Sr2ScBiO6 as having a p-type semiconducting nature with an indirect bandgap value of 2.765 eV. Moreover, the mechanical properties analysis and the related elastic constants demonstrate the anisotropic nature of the Sr2ScBiO6 with decent mechanical stability. Apart from that, the Sr2ScBiO6 was considered a brittle non-central force solid with dominant covalent bondings. The varying optical parameter evaluations highlighted the potential use of Sr2ScBiO6 in visible-light (VIS) and ultraviolet (UV)-based optoelectronic devices. Furthermore, the semiconducting nature of Sr2ScBiO6 was verified through its thermoelectric response, which revealed that the charge carriers mostly consist of holes. The Sr2ScBiO6 recorded a high figure of merit (ZT) value, confirming that the material would be advantageous in renewable energy and thermoelectric (TE) applications. [ABSTRACT FROM AUTHOR]

Analytical mechanics provides methods for analyzing multibody systems with mathematically equivalent elastic elements. The paper analyzes several of these models, highlighting the advantages and disadvantages offered by each of these methods. The main methods used by the researchers are described in a unitary form, presenting the methods of obtaining the evolution equations in each of these cases, mentioning the strengths and weaknesses of each method. The equations of Lagrange, Gibbs–Appell, Kane, Maggi, and Hamilton are analyzed for the particular case of two-dimensional systems, which present certain particularities that facilitate the analysis. [ABSTRACT FROM AUTHOR]

The paper includes analysis of an elastic chiral waveguide, subjected to gravity, where a coupling between different displacement components is assumed owing to gyroscopic action. The importance of gravity and chirality on the dispersion of waves is demonstrated and behaviour in all regimes, including asymptotic ones, is addressed and linked to the value of the chirality parameter. In the transient regimes, we analyse chiral imperfect temporal interfaces in the waveguide subjected to gravity. [ABSTRACT FROM AUTHOR]

This paper aims at quantifying the uncertainties and their propagation effects in the numerical modelling of a cable-stayed bridge. To this purpose, the uncertainty quantification approach is implemented in a probabilistic finite element geometrically nonlinear elastic analysis performed in ANSYS®. The objective of this paper is to evaluate the impact of statistical treatment of significant parameters on the results and validate a predictive model. Given the uncertainties associated with the input parameters, the propagation of uncertainties of output parameters is evaluated by sampling-based approaches using Monte Carlo method. Finally, the probability density function of outputs is compared with experimental data to extract a measure of confidence in the numerical results. The methodology provides a tool to evaluate the effects of model parameter uncertainty on the modal response of the bridge. Although the results presented in this study are limited to a numerical model of a cable-stayed bridge, this methodology can be readily applied to the different bridges and structural typologies. [ABSTRACT FROM AUTHOR]

A novel quadrature element for performing plane stress elastoplastic analysis is introduced in this paper. Differing from the popular finite-element method, the quadrature-element method (QEM) first evaluates the integration in the weak-form statement of the problem by an integral quadrature scheme, and then approximates the differentiation at the discrete integration points by the differential quadrature analog. As a result, the QEM avoids construction of shape functions and obtains higher-order elements easily by just increasing the order of integration. The usage of higher-order elements leads to more accurate solutions and coarser geometric meshes without detriment to the computational scale because the number of degrees of freedom is maintained. In addition, the element nodes in the QEM are the same as the integration points that possess physical meanings such as strains and stresses, which is crucial in the elastoplastic analysis for determining the elastic/plastic state of the nodes. A straightforward elastoplastic quadrature-element formulation is developed. Incremental-iterative and return mapping solution schemes are adopted to implement the quadrature element for the elastoplastic analysis. Numerical examples are presented to demonstrate the effectiveness and high accuracy of the proposed approach. [ABSTRACT FROM AUTHOR]

The stability issues of the tower column (hereinafter referred to as 'tower') in the cable-stayed bridge are studied in this paper. Two types of cable-stayed bridges are considered, namely inclined tower cable-stayed bridges without backstays and floating single-tower cable-stayed bridges. Based on the structure feature of the inclined tower cable-stayed bridge without backstays, a novel double-beam model with discrete springs is established to facilitate the linear elastic buckling analysis of the tower. To solve the model, the transfer matrix method is applied, and the stability characteristic equation of the system is derived by considering the boundary and continuity conditions. In this way, the effective length factors for the longitudinal stability of the tower are obtained. At the same time, the finite element method is utilized to verify the results obtained by the proposed model and method. Then, the parametric analysis is conducted to explore the effects of some structure parameters on the effective length factor of the tower. In addition, the influence on the effective length factor of the tower is investigated in detail when the steel cables are replaced with CFRP cables for an inclined tower cable-stayed bridge without backstays. Finally, the same processing method is extended to derive the effective length factor of the tower in the floating single-tower cable-stayed bridge. The comparison with the results of the finite element method confirms the feasibility of the present method again. [ABSTRACT FROM AUTHOR]

In this paper, the free vibration behavior of isotropic and orthotropic cylindrical shell panels with variable curvature subjected to certain ends boundary conditions is analyzed by the transfer matrix technique and solved by the Romberg integration approach. Flügge's shell theory is employed to model the governing three-dimensional equations of vibration and Fourier's approach is used to deform the displacement fields as trigonometric functions in the longitudinal direction. As a result of a semi-analytical procedure is conducted, the coupled governing equations of panel problem can be written in a matrix partial differential equation of first order with variable coefficients and reduced from the two-dimensional problem to one-dimensional one which is solved numerically as an initial-value problem. The proposed model is applied to get the natural frequencies and mode shapes for the vibration behavior of two-side simply-supported cylindrical panels with simply-supported, free-free, clamped-free and clamped-clamped ends boundary conditions lying at their curved edges. The sensitivity of the vibration behavior to the variety of curvature, panel parameters and material orthotropy of shell is studied. [ABSTRACT FROM AUTHOR]

The elastic analysis of thick-walled spheres made of functionally graded materials (FGMs) is considered to be one of the most important areas in many engineering designs. This paper presents the stresses and displacement fields in an FGM thick-walled sphere under constant interior and exterior pressure. The investigation was carried out using analytical and numerical methods. Exact and finite element (FE) models of the pressurized spherical vessel were created, assuming and implementing continuous changing of Young modulus along the radial direction. It is considered that the elastic modulus of the FGMs varies with thickness according to the nonlinear generalized formula. For a pressurized FGM sphere, the analytical solutions for displacement and stress distribution were developed and demonstrated in the radial direction. Finally, the analytical results are compared to the results from the FE analysis. [ABSTRACT FROM AUTHOR]

In situ analysis and visualization have grown increasingly popular for enabling direct access to data from high-performance computing (HPC) simulations. As a simulation progresses and interesting physical phenomena emerge, however, the data produced may become increasingly complex, and users may need to dynamically change the type and scale of in situ analysis tasks being carried out and consequently adapt the amount of resources allocated to such tasks. To date, none of the production in situ analysis frameworks offer such an elasticity feature, and for good reason: the assumption that the number of processes could vary during run time would force developers to rethink software and algorithms at every level of the in situ analysis stack. In this paper we present Colza, a data staging service with elastic in situ visualization capabilities. We demonstrate the use of Colza with the Deep Water Impact and the AMR-Wind simulations, coupling them with the ParaView Catalyst and Ascent in situ libraries, and show that Colza enables dynamic rescaling of these widely-used frameworks with no interruption to the simulation or staging service. We highlight the challenges of enabling such elasticity, which requires overcoming these frameworks' reliance on MPI, using distinct engineering approaches, namely dependency injection and dependency overload. To the best of our knowledge, this work is the first to enable elastic in situ visualization capabilities for HPC applications on top of existing production analysis tools. • We introduce Colza, an elastic service for in situ analysis of HPC applications. • We present two methods of integrating Colza with existing in situ frameworks. • We evaluate Colza on ANL's Theta and NERSC's Cori supercomputers. [ABSTRACT FROM AUTHOR]

In this paper, based on the theory of elastic structure analysis, considering the rotational softening and centrifugal stiffening of the blade, the dynamic model of the fir-tree rotating blade and the macroslip hysteresis model of the dry friction on the contact surface of fir-tree tenon are established. Based on elastic mechanics, the pressure distribution model of fir-tree tenon is innovatively established and the relationship between fit clearance and contact pressure has been derived. After the blade is discretized by the finite element method, the dynamic equation of the blade is solved iteratively by the Newmark-β numerical integration method. According to the dynamic equation of the blade, the influence of the change of the tenon angle on the forced response and contact stress of the blade is derived. Finally, some novel conclusions are obtained by analyzing the influence of pressure distribution, tenon angle, friction coefficient, rotational speed, and aerodynamic excitation on blade vibration characteristics. It provides a scheme and relevant basis for the design and development of tenon blades with the most damping effect at different speeds in industrial practice. [ABSTRACT FROM AUTHOR]

This paper reports an assessment of structure damages after the Richter magnitude 6.4 Puerto Rico earthquake that occurred on January 7, 2020. A review of the seismicity of the region and the postdisaster investigation of structural damages is first presented. The paper then focuses on explaining the failure modes of 2-story residential structures with open first story, which demonstrated the classical soft story behavior. The typological characterization of the failure modes is investigated using a nonlinear elastic dynamic analysis with a single degree of freedom model, which illustrates the contributions from partial to full construction of infill walls to the stiffness of the 2-story structures. The results indicate that the completion of the infill walls can significantly improve the stiffness of these structures and reduce damages to the structures. [ABSTRACT FROM AUTHOR]

This paper introduces a set of numerical methods for Riemannian shape analysis of 3D surfaces within the setting of invariant (elastic) second-order Sobolev metrics. More specifically, we address the computation of geodesics and geodesic distances between parametrized or unparametrized immersed surfaces represented as 3D meshes. Building on this, we develop tools for the statistical shape analysis of sets of surfaces, including methods for estimating Karcher means and performing tangent PCA on shape populations, and for computing parallel transport along paths of surfaces. Our proposed approach fundamentally relies on a relaxed variational formulation for the geodesic matching problem via the use of varifold fidelity terms, which enable us to enforce reparametrization independence when computing geodesics between unparametrized surfaces, while also yielding versatile algorithms that allow us to compare surfaces with varying sampling or mesh structures. Importantly, we demonstrate how our relaxed variational framework can be extended to tackle partially observed data. The different benefits of our numerical pipeline are illustrated over various examples, synthetic and real. [ABSTRACT FROM AUTHOR]

Elastic coupling is extensively used for passive control of modern structures. This design philosophy has been extensively explored in composite beams, which are inherently inhomogeneous and anisotropic. Such in-depth investigation is not available for homogeneous-anisotropic beams. This paper investigates elastic coupling in homogeneous-anisotropic beam with elliptical cross section using variational asymptotic method (VAM). It is observed that the mere introduction of anisotropy does not couple the system completely. The coupling is tuneable and tailorable, depending on the material properties, their spatial distribution (homogeneity/inhomogeneity), and the geometrical parameters of the beam. [ABSTRACT FROM AUTHOR]

An improved time-domain spectral element method (ITSEM) is developed for seismic analysis of I-sectioned steel structures in this paper. The developed method considers the effect of section type on spectral stiffness using shear correction coefficient. In the calculation process of the time-domain spectral stiffness and mass matrices, the invariant integral operations of the element matrices are extracted and saved in advance. Thus, the global mass and stiffness matrices of the structures can be obtained only by simple addition, subtraction, multiplication and division operations, which greatly improves computational efficiency. Next, the natural frequencies of a I-sectioned beam are computed and compared with the finite element method (FEM) and analytical results to validate the ITSEM. Then, the seismic responses of a ten-story steel frame using ITSEM are obtained and compared with those by FEM, which proves the effectiveness, accuracy and high efficiency of ITSEM in elastic seismic analysis. [ABSTRACT FROM AUTHOR]

The geometry and mechanical behavior of concrete bridge towers are complex. Hence, it is important to generate a rational mechanical analysis model for structural design. The method of strut‐and‐tie models (STMs) is an effective way to analyze disturbed regions (D‐regions) such as the anchorage zones of cables in bridge towers. This paper provides a detailed analysis of the elastic stress distribution on the bridge tower of a cable‐stayed bridge with two cable planes. The vertical component of the stay cable force was considered for the analysis. Additionally, two different STMs of the bridge tower were developed with the load path method using different horizontal spacings of the stay cables. Based on the minimum energy principle, the optimal STMs of the two different STMs were generated. A detailed calculation method for the configuration of the optimal STMs is presented. In the paper, computational expressions of the internal force for the tie members in the two STMs are also proposed. Overall, this study demonstrated the strong applicability of the proposed STMs for a bridge tower in a cable‐stayed bridge with two cable planes. This can be considered an effective simplified method in the structural design of bridge towers. Furthermore, the study established that the influence of the horizontal distance between stay cables on the mechanical response‐behavior of the structure should be considered in the design of concrete bridge towers. [ABSTRACT FROM AUTHOR]

• The LRBFCM is extended to a 3D dental elastic problem. • The direct method and fictitious node method are used to solve the derivative instability in the LRBFCM. • The maximum von Mises stress of the molar is fully studied by considering different situations. 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 well as the treatments of the boundary conditions are detailed described in this paper. Linear elastic analyses of five different examples are carried out to validate the effectiveness of the proposed approach. The stress difference between a tooth with the dental caries and a healthy tooth is investigated and discussed by the 3D elastic deformation and stress analysis. [ABSTRACT FROM AUTHOR]

With the increasing applications of the planetary roller screw mechanism (PRSM) in mechanical systems particularly machine tools, a comprehensive mathematical model is required to define the kinematic characteristics and relations of the PRSM, such that its performances can be predicted for reliability analysis and design of machine tools. In this paper, the influences of machining and assembly errors on the motion characteristics of the PRSM are analyzed, and the kinematic model of the PRSM is established considering runout errors and elastic deformation. The planetary roller screw mechanism can be considered as a spring-mass system for analysis of the elastic deformation of the ball screw's thread under inertial force. For the spring-mass system, adjacency matrix is introduced to define the relationships between the elastic displacements of the joints and the deformations of the elements. Then, by considering the balance of force and the coordination of deformation, the nonlinear motion model of the double-nut roller screw is established. The effectiveness of the proposed model is verified by comparing the analytical results with the experimental data. [ABSTRACT FROM AUTHOR]

In this paper, an equilibrium problem for two elastic bodies connected by a thin junction (bridge) is analyzed. An existence of solutions is proved. Passages to limits are justified with respect to the rigidity parameter of the junction. In particular, the rigidity parameter tends to infinity and to zero. Limit models are investigated. [ABSTRACT FROM AUTHOR]

In this paper, we study the low-energy d - α elastic scattering within the two-body cluster effective field theory (EFT) framework. The importance of the d (α , α) d scattering in the 6 Li production reaction leads us to study this system in an effective way. In the beginning, the scattering amplitudes of each channel are written in a cluster EFT with two-body formalism. Using the effective range expansion analysis for the elastic scattering phase shift of S, P and D partial waves, the unknown EFT low-energy coupling constants are determined and the leading and next-to-leading orders EFT results for the phase shift in each channel are presented. To verify the accuracy of the results, we compare experimental phase shift and differential cross section data with obtained results. The accuracy of the EFT results and consistency with the experimental data indicate that the EFT is an effective approach for describing low-energy systems. [ABSTRACT FROM AUTHOR]

The Sichuan Basin is a significant region for exploration and development of shale gas in China, and it is essential to clarify the impact of deep shale gas reservoir parameters on cost-effective development at scale to ensure national energy security. Rock physics modeling is a significant means of communicating the physical and elastic parameters of rocks. A rock physics modeling method applicable to fractured shale gas reservoirs is proposed for the current situation of complex fluid relationships in shale gas reservoirs and unclear characteristics of gas identification seismic response. In this paper, based on the Self Consistent Approximation (SCA) model and the differential effective medium (DEM) model, the anisotropic source of shale is used as a starting point to add bound water, kerogen, clay, and brittle minerals, the Schoenberg linear slip theory is used to add fracture disturbance effects, and then the Brown–Korringa model is used to perform fluid replacement under anisotropic conditions. Finally a rock physics model applicable to fractured shale gas reservoirs is obtained, and the established rock physics model is used for analysis of elastic parameters, Thomsen parameters, and fracture weakness parameters. Rock physics tests were performed on shale in southern Sichuan as an example. The experimental results show that the model established by the process can accurately invert the longitudinal and transverse wave velocities of the shale, which can provide a conceptual basis for the study of fractured shale gas reservoirs. [ABSTRACT FROM AUTHOR]

The production of ceramic tiles requires specific technical properties to allow a wide application, including covering floors and walls, building furniture, and decorative items. Current methods of measuring the dimensions of large ceramic tiles seem inadequate for products that exhibit elastic deformation due to their weight affecting the accuracy and precision of measurements. This paper aims to analyze the influence of format, thickness, and typology variables on the elastic deformation of ceramic tiles. Additionally, this study provides an analysis about which products can be measured by the traditional measurement system without compromising the quality of the results. Tests to determine warpage under different support conditions were performed using a laser-equipped coordinate measuring machine. This technology provided typology, thickness and size, and elastic deformation outcomes. In addition, a multilevel factorial design was carried out using analysis of variance (ANOVA) to investigate the influence of the selected variables. The results suggest that all the studied variables affect the elastic deformation due to the weight of ceramic tiles. The effect of interactions between predictor variables is significant mainly for the largest tiles sizes. The results also show that the current measurement method is indicated for tiles smaller than 30 × 30 cm. Further studies will be conducted to develop a new compatible and reliable method to determine the dimensional characteristics of larger ceramic tiles. [ABSTRACT FROM AUTHOR]