Strain gradient

The authors propose a novel BCMO-DNN algorithm for vibration optimization of functionally graded porous microplates. The theory is based on a unified framework of higher-order shear deformation theory and modified strain gradient theory. A hybrid combination of deep learning neural network and balancing composite motion optimization is developed to solve the optimization problems and predict stochastic vibration behaviors of functionally graded porous microplates with uncertainties of material properties.

12p dathienlang1012 03-05-2024 3 0   Download

The paper "Nonlinear vibration of functionally graded porous micro-beams resting on elastic foundation" presents the analysis of nonlinear vibration of functionally graded porous (FGP) micro-beams resting on an elastic foundation. The Euler-Bernoulli beam theory (EBT) and the nonlocal strain gradient theory (NSGT) are considered to establish the equations of motion of the micro-beam. The material properties of the micro-beam are assumed to be changed continuously along thickness direction according to simple power-law distribution.

9p dathienlang1012 03-05-2024 1 0   Download

In this paper, we considered the propagation wave in transversely isotropic piezoelastic medium based on the nonlocal strain gradient theory. Two kinds of scale parameters, namely, the nonlocal parameter and the strain gradient parameter are introduced to account for the size effect of mechanical properties of nanostructures.

18p dianmotminh02 03-05-2024 6 2   Download

A damage diagnosis method for trusses based on incomplete free vibration properties utilizing ensemble learning, e.g. Extreme gradient boosting (XGBoost), is presented in this work. Owing to the lack of measurement sensors, modal features are only measured at master degrees of freedom (DOFs) of a few first models instead of all DOFs of a structural system.

12p viohoyo 25-04-2024 3 2   Download

This paper investigates the bending behavior of beams by considering: (1) the EulerBernoulli beam model, (2) Mindlin’s strain gradient elasticity theory, (3) the von Kármán strain assumptions. The principle of virtual work is used to derive the non-linear governing equations in form of a six-order partial differential equation.

7p viohoyo 25-04-2024 5 2   Download

Based on fundamental equations of the elasticity theory, a unified higher-order shear deformation theory is developed for bending and free vibration analysis of functionally graded (FG) microplates with porosities. The modified strain gradient theory is employed to capture the size effects.

24p viwolverine 11-07-2023 3 2   Download

Bài viết Chẩn đoán hư hỏng kết cấu dàn chịu nhiệt độ và tải trọng động dùng tối ưu hóa ngược và học sâu đề xuất một phương pháp chẩn đoán hư hỏng kết cấu dàn chịu tải trọng động và tải nhiệt độ đồng thời theo ba bước. Trong đó, bước thứ nhất áp dụng Chỉ số năng lượng biến dạng dựa trên đáp ứng gia tốc theo thời gian (Acceleration-based Strain Energy Indicator – ASEI) để chẩn đoán sơ bộ các vị trí có khả năng xảy ra hư hỏng.

13p vihawkeye 26-05-2023 5 3   Download

Based on nonlocal strain gradient theory approach, we have analyzed the nonlinear dynamic response and vibration of sandwich thick plates with functionally graded (FG) face sheets and FG porous core subjected to mechanical, thermal and blast loads on elastic foundations.

15p vimelindagates 18-07-2022 12 3   Download

In this paper, we present detail data of Pliocene - present tectonics and strain rate from GPS measurement and seismic interpretation. Using international reference frame ITRF08, we revealed absolute tectonic velocities of GPS sites with the slip rate to the east between 22 to 25 mm/year, to the south between 4 to 8 mm/year. The present strain rate was determined from present tectonic velocities that were consistent with the recent strain rates determined from seismic profiles, thickness of Pliocene - Quaternary sediments.

24p nguaconbaynhay11 07-04-2021 11 2   Download

The nonlinear free vibration of embedded nanotubes under longitudinal magnetic field is studied in this paper. The governing equation for the nanotube is formulated by employing Euler–Bernoulli beam model and the nonlocal strain gradient theory. The analytical expression of the nonlinear frequency of the nanotube is obtained by using Galerkin method and the equivalent linearization method with the weighted averaging value. The accuracy of the obtained solution has been verified by comparison with the published solutions and the exact solution.

23p nguaconbaynhay11 07-04-2021 19 2   Download

In this study, a simple size-dependent isogeometric approach for bending analysis of functionally graded (FG) microplates using the modified strain gradient theory (MSGT), simple first-order shear deformation theory (sFSDT) and isogeometric analysis is presented for the first time. The present approach reduces one variable when comparing with the original first-order shear deformation theory (FSDT) within five variables and only considers three material length scale parameters (MLSPs) to capture size effects.

13p trinhthamhodang9 10-12-2020 15 0   Download

Foot-and-mouth disease [FMD] is a highly infectious and contagious viral disease of domestic and wild cloven hoofed animals. The disease is controlled by vaccination using inactivated vaccine as one of the important options. The integrity of 146S plays an important role in the efficacy of the vaccine. The currently applied methods like density gradient to check the integrity of the 146S particles are besotted with certain disadvantages. Therefore, we generated monoclonal antibodies (mAbs) specific to 146S of FMDV serotype A [Indian strain].

11p chauchaungayxua4 18-03-2020 14 0   Download

An inspection of a tidal river concrete bridge in the Mekong River Delta discovered a large number of map cracks in most piers within the tidal range. These map cracks distribute nearly vertically and horizontally with a distance of about 15 and 20 cm. Many of them have a width over 1 mm and a depth exceeding the thickness of the reinforcement protection concrete layer. Considering the location and the pattern of cracks, the most acceptable hypothesis on their cause was the strain gradient in concrete induced by the change of moisture content during tide rise and fall, i.e.

11p thayboitinhyeu 02-03-2020 32 1   Download

The paper develops a general framework to derive the effective properties of quasi-periodic elastic medium. By using the asymptotic expansion method, the solution is expanded to the second order by solving a sequence of minimization problems.

24p danhdanh11 09-01-2019 22 1   Download

This work is devoted to the analysis of the stability of the homogeneous states of a bar made of a brittle strain softening material submitted to a tensile loading. We distinguish two types of damage models: local damage models and gradient damage models. We show that a local damage model necessarily leads to the unstability of the homogeneous response once the first damage threshold is reached. On the contrary, in the case of a gradient damage model, viewed as a regularization of the underlying local model, the homogeneous damage states of “sufficiently small" bars are stable.

12p thienthanquydu 21-10-2018 28 0   Download

The interest of gradient models is then discussed in the context of damage mechanics and crack simulation. The phenomenon of strain localization in a time-dependent or timeindependent process of damage is explored as a convenient numerical method to simulate the propagation of cracks, in relation with some recent works of the literature, cf. Bourdin & Marigo [3], Lorentz & al [5], Henry & al [12].

9p thienthanquydu 17-10-2018 19 1   Download