Transient Response of a Circular Nanoplate Subjected to Low Velocity Impact

2017 ◽  
Vol 09 (08) ◽  
pp. 1750114 ◽  
Author(s):  
Jie Liu ◽  
Hua Liu ◽  
Jia-Ling Yang ◽  
Xi-Qiao Feng
Keyword(s):  
Transient Response ◽  
Plate Theory ◽  
Surface Elasticity ◽  
Expansion Method ◽  
Surface Effects ◽  
Dynamic Responses ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Surface Residual Stress ◽  
Impact Problems

The transient response of a circular nanoplate subjected to the normal impact by a nanosphere (e.g., C[Formula: see text]) is investigated theoretically. The nanoplate is modeled by the Kirchhoff thin plate theory. Gurtin–Murdoch’s theory is employed to account for the surface effects of the nanoplate with surface elasticity and surface residual stress. The van der Waals interaction between the nanosphere and the nanoplate is also taken into account. The governing equations for the vibration of the nanoplate impinged by a rigid nanosphere are established by using the Hamilton’s principle. The displacement field in the circular nanoplate is obtained by using the Fourier–Bessel expansion method. We reveal some physical mechanisms in the nanoimpact problem that are different from those in macroscopic impact problems, and surface effects have pronounced influences on the dynamic responses of a plate when its thickness shrinks to a few nanometers.

Analysis of Residual Stresses on the Vibration of a Circular Sensor Diaphragm with Surface Effects

2016 ◽  
Vol 33 (3) ◽  
pp. 323-329 ◽  
Author(s):  
S.-S. Zhou ◽  
S.-J. Zhou ◽  
A.-Q. Li ◽  
B.-L. Wang
Keyword(s):  
Residual Stresses ◽  
Natural Frequency ◽  
Flexural Rigidity ◽  
Plate Theory ◽  
Surface Elasticity ◽  
Surface Effects ◽  
Transition Range ◽  
Biochemical Sensors ◽  
Tension Parameter ◽  
Wide Range

AbstractResonant micro-biochemical sensors play important roles in a wide range of emerging applications to detect biochemical molecules. As the resonators of micro-biochemical sensors, the vibration characteristics of circular sensor diaphragms are important for the design of diaphragm-based resonant micro-biochemical sensors. In this paper, the influence of residual stresses on the vibration of a circular sensor diaphragm with surface effects is analyzed. Based on the Kirchhoff's plate theory and surface elasticity theory, the governing equation is presented. The material characteristic lengths for different surface effects are obtained. The influences of residual stresses on the effective flexural rigidity and natural frequency of the diaphragm with surface effects are discussed. Results show that the influence of residual stresses on the effective flexural rigidity becomes obvious with the increasing of residual stresses. The first order natural frequency increases rapidly when the tension parameter is larger than 30 for the stiffened surfaces, while for the softened surfaces the value is 10. Moreover, surface effects can influence the transition range of diaphragm from the plate behavior to membrane behavior in terms of the tension parameter. The transition range can be enlarged by the stiffened surface and be shortened by the softened surface. The analysis and results are helpful for the design of sensor diaphragm-based resonant micro-biochemical sensors and some related researches.

Low-Velocity Impact on a Functionally Graded Circular Thin Plate

2006 ◽  
Author(s):  
Pantele Chelu ◽  
Liviu Librescu
Keyword(s):  
Plate Theory ◽  
Equation System ◽  
Functionally Graded ◽  
Low Velocity Impact ◽  
Thin Plates ◽  
Low Velocity ◽  
Alternative Analysis ◽  
Velocity Impact ◽  
Graded Material ◽  
The Impact

In this paper, an alternative analysis strategy based on a Wavelet-Galerkin scheme specially tailored to solve impact problems of functionally graded orthotropic thin plates subjected to low-velocity impact is presented. The plate considered to be circular, is assumed to be clamped on its lateral edge and has internal supports of rigid, elastic and viscoelastic types. The material properties of the plate are represented in the form of exponential functions of the thickness coordinate. A rigid spherical indenter impacts the plate. The study is based on the classical lamination plate theory (CLT). An advanced contact law of the Hertzian type is adopted. A nonlinear Volterra integral equation system is obtained in the following unknown functions: the impact force and the dynamic reaction forces at the rigid, elastic and viscoelastic internal point supports. Numerical simulations displaying the contact force, the transversal displacement and the penetration depth are graphically presented, and pertinent conclusions regarding the implications of incorporation of graded material systems are outlined.

Surface Effects on Large Deflection of Nanobeams Subjected to a Follower Load

2020 ◽  
Vol 12 (06) ◽  
pp. 2050067
Author(s):  
Yun Xing ◽  
Yi Han ◽  
Hua Liu ◽  
Jialing Yang
Keyword(s):  
Large Deformation ◽  
Surface Stress ◽  
Large Deflection ◽  
Surface Effect ◽  
Surface Elasticity ◽  
Surface Effects ◽  
Surface Residual Stress ◽  
Residual Surface Stress ◽  
Deformation Problem ◽  
Cross Sectional Dimension

As a basic element of the micro/nanodevices, nanobeams have remarkable physical properties and have attracted considerable attention in the previous studies. However, previous publications did not study the large deformation problem of nanobeams under follower loading when the surface effect becomes significant and especially for the influence of surface effect on mechanical behaviors of the nanobeams under follower loading remains unclear. In this paper, we investigated the large deformation behavior of nanobeams subjected to follower loads in consideration of the surface effects. The mechanical model of large deflection of extensible cantilever nanobeams under follower loading is presented in combination with the surface elasticity and residual surface stress, and then a MATLAB program of shooting method with a technique for determining the initial value was developed to solve the problems. The results indicate that the surface effects have an important influence on the large deflection of nanobeams under follower loading: when the surface residual stress is positive, the maximums of displacement in horizontal and vertical directions and the rotation angle of the free end become lager, but the corresponding follower force related to those maximums becomes smaller. When the residual surface stress is negative, the results are the opposite. In addition, the influence of the cross-sectional dimension of the nanobeams under follower loading on surface effects was discussed. This work is beneficial to understand the mechanism of large deformation of nanobeams with surface effects subjected to follower loads, and can also provide inspirations to design advanced nanomaterials and nanoscaled devices.

Dynamic responses of corrugated cylindrical shells subjected to nonlinear low-velocity impact

2022 ◽  
pp. 107321
Author(s):  
Yunfei Liu ◽  
Wenyang Hu ◽  
Runze Zhu ◽  
Babak Safaei ◽  
Zhaoye Qin ◽  
...  
Keyword(s):  
Cylindrical Shells ◽  
Dynamic Responses ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact

scholarly journals Dynamic responses of reinforced concrete slabs under sudden impact loading

2021 ◽  
Vol 20 (2) ◽  
pp. 346-358
Author(s):  
Recep Tuğrul Erdem ◽  
Keyword(s):  
Reinforced Concrete ◽  
Impact Loading ◽  
Experimental Results ◽  
Dynamic Responses ◽  
Low Velocity Impact ◽  
Experimental Program ◽  
Low Velocity ◽  
Velocity Impact ◽  
Impact Effect ◽  
Rc Slabs

Reinforced concrete (RC) slabs may be subjected to low-velocity impact effect in their service lives. In this study, it is aimed to investigate dynamic responses of two-way rc slabs. So, a total of 6 slabs with 500x500, 550x550 and 600x600 mm side lengths and having same thickness are both experimentally and numerically investigated under low velocity impact loading. Two different reinforcement configurations are used in the production of each slab. A drop test setup is designed for the experimental study. Besides, measurement devices such as accelerometer, lvdt, dynamic load cell, data logger and optic photocells are used in the experimental program. Experiments on the specimens are carried out for the same level of impact energy. Acceleration, displacement and impact load values of slabs are presented by time dependent graphs. In addition, cracks and deformations are observed during tests. In the numerical part of this study, a detailed finite element procedure where explicit dynamic analysis is performed by Abaqus finite elements software is established. The simulations are performed for each test specimen under impact effect and analysis results are used in the verification of experimental results. The relationship between experimental and numerical studies is comparatively examined in terms of crack patterns and average ratios of accelerations, displacements, impact loads. Finally, it is considered that the proposed numerical model could be used in the evaluation of experimental results under impact loading.

Peridynamic Analysis of Cracked Beam Under Impact

2020 ◽  
Vol 36 (4) ◽  
pp. 451-463
Author(s):  
M. J. Akbari ◽  
S. R. Kazemi
Keyword(s):  
Crack Growth ◽  
Initial Crack ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Peridynamic Theory ◽  
Analysis Process ◽  
Non Local ◽  
Impact Problems ◽  
Material Points ◽  
The Impact

ABSTRACTSpecific conditions at the tip of a crack and discontinuities in a material are the challenges in analyzing the growth of cracks using conventional methods. In recent years, a method has been developed based on the non-local mechanics, called peridynamic theory, which has improved the analysis process of such structures. In this theory, the points of matter whose displacement or displacement derivatives are discontinuous are not distinguished from other material points. In this paper, we employed the bond-based peridynamic theory to investigate the rate of crack propagation and the path of crack growth in a beam with an initial crack due to low velocity impact. Two beams made of polymethyl-methacrylate (PMMA) and steel alloy with different projectile shapes were considered. The effects of changes in the impact velocity and the fracture toughness were studied and the obtained results were validated with other conducted studies. The crack path was predicted successfully and the branching of the crack was captured. The results confirm the ability of the peridynamic theory to model the crack growth in impact problems.

Analytical Solution for Buckling Behavior of FGM Plate Considering Surface Effect Based on General Third-Order Plate Theory and Non-local Theory

2020 ◽  
Vol 20 (11) ◽  
pp. 2050125
Author(s):  
J. R. Zhong
Keyword(s):  
Surface Effect ◽  
Plate Theory ◽  
Plate Thickness ◽  
Surface Elasticity ◽  
Local Theory ◽  
Solution Technique ◽  
Surface Residual Stress ◽  
Third Order ◽  
Stress Surface ◽  
Non Local

In this paper, the buckling characteristic of FGM plate considering the surface effect is studied based on general third-order plate theory and non-local theory. The surface effect of FGM plate is captured by the surface elasticity theory. The Kirchhoff hypothesis is released by employing parabolic variation of transverse shear strains. By using Navier solution technique, analytical solutions of buckling loads of FGM plate with surface effect are given, and detailed parametric studies are presented to show the relationship between surface effects and the plate thickness, power-law index, surface residual stress, surface moduli and non-local parameter. Furthermore, the surface effect on the buckling characteristic of FGM plate is also discussed.

Thermoelastoplastic Behavior of a HSLA Steel Plate Subjected to Low-Velocity Impact

2015 ◽  
Vol 15 (03) ◽  
pp. 1450056 ◽  
Author(s):  
Hao-Jie Jiang ◽  
Hong-Liang Dai ◽  
Kai Zhu ◽  
Yi-Ming Fu
Keyword(s):  
Steel Plate ◽  
Plate Theory ◽  
Yield Criterion ◽  
Hsla Steel ◽  
Contact Process ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact ◽  
Mixed Hardening ◽  
Environment Temperature

The thermoelastoplastic behavior of a high strength low alloy (HSLA) steel plate subjected to low-velocity impact is investigated in this paper. A yield criterion related to the spherical tensor of stress is proposed to describe the mixed hardening of the orthotropic material. Based on the classical nonlinear thin plate theory, the incremental nonlinear motion equations are obtained, and are solved by the combination of finite difference method and Newmark method with iterations. To explain the contact process, a thermoelastoplastic contact criterion is developed, of which the validity has been proved. Numerical results show that the radius of the impactor, initial impact velocity, environment temperature, and the thickness of the HSLA steel plate all have great influences on the thermoelastoplastic behavior of the HSLA steel plate subjected to low-velocity impact.

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