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We investigate the contact between a one-dimensional (1D) hexagonal quasi-crystal (QC) half-space and a rigid elliptic indenter. The three-dimensional (3D) phonon–phason fields in the half-space are derived in terms of elementary functions using the generalized potential theory method. Closed-form solutions are obtained for significant physical quantities, including the contact stresses, indentation...
This study contributes to a possibility of evaluating composite structures configuration such as steel and concrete using buckling and volume constraints based on multi-material topology optimization. A Jacobi active-phase algorithm is used to generate multiphase topology optimization. It provides a rational solution appropriated to the topology optimizer, Method of Moving Asymptotes due to the conflict...
The fatigue analysis of linear discretized structures with uncertain axial stiffnesses modeled as interval variables subjected to stationary multi-correlated Gaussian stochastic excitation is addressed. Due to uncertainty, all response quantities, including the expected fatigue life, are described by intervals. The key idea is to extend an empirical spectral approach proposed by Benasciutti and Tovo...
The application of performance-based design (PBD) requires the modeling of the dynamic response of the system beyond the elastic limit. If probabilistic PBD is considered, this implies the need to propagate uncertainties through non-linear dynamic systems. This paper investigates the possibility of using advanced metamodeling techniques in order to define a computationally tractable approach for propagating...
Capacity domains of reinforced concrete elements, computed according to Eurocode 2 provisions, have been investigated from a probabilistic perspective in order to examine the variability of the failure probability over different regions of the domain boundary. To this end, constitutive parameters, such as limit stresses and strains, have been defined as random variables. Discretized ultimate limit...
Strong crosswinds have a great influence on the safety of road vehicles. Different vehicle types may have different behavior under strong crosswinds, thereby leading to different dominant accident modes and accident risks. In order to compare the crosswind stability of road vehicles, a probabilistic method based on reliability analysis has been applied in this paper. The crosswind is simulated as...
The present paper deals with the evaluation of the structural response of single-cracked beam-like structures under deterministic time variant excitations assuming the crack depth as an uncertain parameter. Taking into account the unavoidable uncertainty affecting also the damage characteristics in practical applications, the crack depth is modelled by both a stochastic and an uncertain-but-bounded...
The dynamics of beams equipped with tuned mass dampers is of considerable interest in engineering applications. Here, the purpose is to introduce a comprehensive framework to address the stochastic response of the system under stationary and non-stationary loads, considering inertia effects along the spring of every tuned mass damper applied to the beam. For this, the key step is to show that a tuned...
Numerical modeling of actual structural systems is a very complex task mainly due to the lack of complete knowledge on the involved parameters. Simplified assumptions on the uncertain geometry, material properties and boundary conditions make the numerical model response differ from the actual structural response. Improvements of the finite element (FE) models to obtain accurate response predictions...
In the present paper, the elastic mechanical characteristics of masonry samples, whose texture is not visible due to plaster, are estimated by means of homogenization technique applied through thermographic images. In particular, three masonry samples with different textures have been purposely built. The chosen textures were periodic, quasi-periodic and random. The images, taken with a thermocamera,...
In this paper the nonstationary response of a class of nonlinear systems subject to broad-band stochastic excitations is examined. A version of the Path Integral (PI) approach is developed for determining the evolution of the response probability density function (PDF). Specifically, the PI approach, utilized for evaluating the response PDF in short time steps based on the Chapman–Kolmogorov equation,...
A novel statistical linearization technique is developed for computing stationary response statistics of randomly excited coupled bending-torsional beams resting on non-linear elastic supports. The key point of the proposed technique consists in representing the non-linear coupled response in terms of constrained linear modes. The resulting set of non-linear equations governing the modal amplitudes...
The scope of this paper is to evaluate the performance and computational efficiency of various stochastic simulation methods for a stochastic based reliability assessment of railway bridges subjected to high-speed trains. Depending on the degree of sophistication, application of crude Monte Carlo simulation to a realistic mechanical model of the uncertain bridge-train interacting dynamical system...
Due to the combined effect of the background wind, the translation of the downburst and the radial nature of the downdraft after the touchdown, a peculiar characteristic of a thunderstorm outflow as detected by an anemometer or experienced by a structure is the potential variation of the flow direction. The study of the wind-excited response of structures has habitually neglected this issue because,...
Generalized independent coordinates are typically utilized within an analytical dynamics framework to model the motion of structural and mechanical engineering systems. Nevertheless, for complex systems, such as multi-body structures, an explicit formulation of the equations of motion by utilizing generalized, independent, coordinates can be a daunting task. In this regard, employing a set of redundant...
The tooth profile modification was considered as a part of the static error of a gear transmission system. Subsequently, the thermodynamic equation of the system after the tooth profile modification was derived by introducing the equivalent static transmission error and thermal meshing stiffness. The effect of the tooth profile modification on the dynamic characteristics of the gear transmission system...
We consider an oscillation-based actuator in which directed motion is generated by a spherical contact subjected to superimposed oscillations in vertical and horizontal directions. We consider the full dynamical problem with account of contact forces arising due to the superimposed periodic loading. We find that the system can have two regimes: either motion in one direction or stick–slip motion,...
In previous work in the literature, a kinetic derivation of a logarithmic nonlinear Schrödinger equation incorporating a de Broglie–Bohm term has been obtained in a capillarity context. Here, gausson-type solutions are constructed for such an NLS model. A novel two-parameter class of reciprocal transformations is shown to leave the 1 + 1-dimensional Korteweg capillarity system invariant and is applied...
Shape memory polymers (SMPs) are a class of smart materials which can recover their shape even after many shape changes in application of an external stimulus. In this paper, flexural behavior of a composite beam, constructed of a corrugated part filled with SMPs, is studied. This composite beam is applicable in sensor and actuator applications. Since the corrugated profiles display higher stiffness-to-mass...
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