Contact Dynamics and Stress Field of Fluid-Conveying GRC Nanotubes

Abstract Fluid-conveying nanotubes play key roles in micro-nano electromechanical systems. The contact dynamic response and stress field of the fluid-conveying graphene reinforced composite (GRC) nanotube under lateral low-velocity impact are studied. The size-dependent models considering slip flow, nonlocal stress and strain gradient effect are established. The governing equations of flow-inducing post buckling and contact vibration are derived based on a refined beam theory, in which the post-buckling equilibrium provides the initial configuration for the impact vibration analysis. A computation mode of two-step perturbation-Galerkin truncation-Runge-Kutta method is developed to study the contact dynamic responses. Through the convergence analysis, the truncation terms required to ensure the accuracy are obtained. The contact force curves and the midspan displacement time history curves are acquired, and the dynamic snap-through instability behaviors of the nanotube in the flow-inducing post-buckling state are revealed. Also, the stress field in the impact process is obtained to provide theoretical results to guide the strength design. Numerical results reveal the dual influence law of nonlocal stress and strain gradient on the contact dynamic response and stress field and provide the flow velocity range sensitive to the nano effects.

ANALYSIS OF ELASTIC IMPACT ON THIN SHELL STRUCTURES

International Journal of Modern Physics B ◽

10.1142/s0217979208046761 ◽

2008 ◽

Vol 22 (09n11) ◽

pp. 1349-1354 ◽

Cited By ~ 2

Author(s):

SHIUH-CHUAN HER ◽

CHING-CHUAN LIAO

Keyword(s):

Differential Equation ◽

Contact Force ◽

Thin Shell ◽

Time History ◽

Dynamic Responses ◽

Low Velocity Impact ◽

Integro Differential Equation ◽

Impact Process ◽

Non Linear ◽

In this paper, a solution method for the response of a thin shell structure subjected to low velocity impact by a sphere is presented. The governing equation of the impact process is obtained by simultaneously solving the equations of motions for the sphere and shell. The derivation is based on the explicit expression of the displacement of the mid-surface of the shell under a single impulse load acting normal to apex of the shell. Incorporating the theory of convolution and Hertz contact law, a non-linear integro-differential equation in terms of the indentation of the contact, for the impact process is derived. The non-linear integro-differential equation is solved by the numerical scheme of Runge-Kutta method to obtain the time history of the contact force at the impact point of the shell. The contact force is then applied on the apex of the shell, the dynamic responses of the shell including the displacement and stress are obtained by the finite element method. The results are validated with the experimental test and numerical calculation published in the literatures. The effects of the radius and velocity of the impactor on the impact response is investigated through parametric study.

Finite Element Analysis of a Single-Layer Reticulated Dome under Impact Loading

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.163-167.327 ◽

2010 ◽

Vol 163-167 ◽

pp. 327-331 ◽

Cited By ~ 1

Author(s):

Liang Zheng ◽

Zhi Hua Chen

Keyword(s):

Finite Element ◽

Dynamic Response ◽

Impact Force ◽

Impact Load ◽

Residual Deformation ◽

Time History ◽

Single Layer ◽

Element Analysis ◽

Deformation Stage ◽

Finite element model of both the single-layer Schwedler reticulated dome with the span of 50m and a Cuboid impactor were developed, incorporating ANSYS/LS-DYNA. PLASTIC_KINEMATIC (MAT_003) material model which takes stain rate into account was used to simulate steel under impact load. The automatic point to surface contact (NODES TO SURFACE) was applied between the dome and impact block. Three stages of time history curve of the impact force on the apex of the single-layer Scheduler reticulated dome including the impact stage, stable stalemate stage, the decaying stage were generalized according to its dynamic response. It must be pointed out that the peak of the impact force of the single-layer reticulated dome increase with the increase of the weight and the velocity of the impact block, but the change of the velocity of the impact block is more sensitive than the change of weight of the impact block for the effect of the peak of the impact force, and a platform value of the impact force of the single-layer reticulated dome change near a certain value, and the duration time of the impact gradually increase. Then four stages of time history curve of the impact displacement were proposed according to the dynamic response of impact on the apex of the single-layer reticulated dome based on numerical analysis. Four stages include in elastic deformation stage, plastic deformation stage, elastic rebound stage, free vibration stage in the position of the residual deformation.

Numerical Simulation and Experimental Study on Fluid-Filled Hemispherical Shell under Impact

10.4028/www.scientific.net/amm.364.172 ◽

2013 ◽

Vol 364 ◽

pp. 172-176

Author(s):

Hui Wei Yang ◽

Bin Qin ◽

Zhi Jun Han ◽

Guo Yun Lu

Keyword(s):

Numerical Simulation ◽

Dynamic Response ◽

Impact Load ◽

Elastic Recovery ◽

Plastic Hinge ◽

Time History ◽

Hemispherical Shell ◽

History Of ◽

Local Impact ◽

The dynamic response of fluid-filled hemispherical shell in mass impact is studied by experiment using DHR9401. Combining the time history of impact force with experimental observation of the deformation process, it can be seen that the dynamic response can be divided into four stages: the flattening around the impact point, the forming and expanding outward of shell plastic hinge, the plastic edge region flatten by the punch, and elastic recovery. The experimental results show that: Because the shell filled with liquid, the local impact load that the shell suffered is translated into area load and loads on the inner shell uniformly, so that it has a high carrying capacity. Numerical simulation is used to study the time history of energy absorption of different shell structures. The result shows that the crashworthiness of sandwich fluid-filled shell is improved greatly. Under the certain impact energy, deformation of its inner shell is very small, which can provide effective security space.

Analysis of Seismic Dynamic Response of Tunnel in Karst Areas

10.4028/www.scientific.net/amm.90-93.2108 ◽

2011 ◽

Vol 90-93 ◽

pp. 2108-2111

Author(s):

Lin Jie Chen ◽

Bo Liang ◽

Zhi Yong Wang

Keyword(s):

Dynamic Response ◽

Soil Structure ◽

Interaction Model ◽

Time History ◽

Side Wall ◽

Internal Force ◽

Dynamic Responses ◽

Karst Caves ◽

History Analysis ◽

Karst Areas

Based on soil-structure interaction model, the seismic dynamic response of tunnel in karst areas were performed by using viscous-spring artificial boundary and time history analysis method. In combination with the Menglian tunnel engineering on the Bao-Teng Highway in Yunnan, in different sizes and sites karst caves conditions, the dynamic responses of displacement and internal force on control points of the tunnel structure were obtained. The results show that comparatively large interal forces, under the high-intensity earthquake conditions, will appear on the side wall of the tunnel which through karst areas, less ones on arch crown and inverted arch parts, and the differential displacements of arch crown reach to the maximum. When the karst caves are located in the side of the tunnel, it make the seismic dynamic response get more large, which make the surrounding rock must be strengthened treatment. The results provide useful reference for the aseismatic design of tunnel.

Experiment and Simulation Study on the Dynamic Response of RC Slab under Impact Loading

Shock and Vibration ◽

10.1155/2021/7127793 ◽

2021 ◽

Vol 2021 ◽

pp. 1-15

Author(s):

Yue Wang ◽

Jun Liu ◽

Zhimin Xiao ◽

Futian Zhao ◽

Yi Cheng

Keyword(s):

Dynamic Response ◽

Impact Loading ◽

Impact Resistance ◽

Great Influence ◽

Time History ◽

Reinforcement Ratio ◽

Slab Thickness ◽

Drop Hammer ◽

Rc Slab ◽

Reinforced concrete (RC) slab is an important component in civil construction and protection engineering, and its dynamic response under impact loading is a complex mechanical problem, especially for two or multiple continuous impact loads. In this paper, a series of drop hammer impact tests were carried out to investigate the dynamic response of RC slabs with two successive impacts. The time history of impact force and the failure characteristic of the slab surface were recorded. Moreover, four influence factors, including slab thickness, reinforcement ratio, impact location, and drop hammer height have been discussed. Besides, a 3D numerical model based on the finite element method (FEM) was established to expand the research of constrained force, deflection, and vertical stress of an RC slab. The results show that increasing the slab thickness and reinforcement ratio can improve the impact resistance of an RC slab. The impact point location and drop hammer height have a great influence on the dynamic response of the RC slab. In addition, the RC slab will have more obvious damage under the second impact, but the dynamic response becomes weaker. It may be because of the local damage in the concrete caused by the first impact that would weaken the propagation of vibration.

Dynamic Response Analysis of Retaining Dam under the Impact of Solid-Liquid Two-Phase Debris Flow Based on the Coupled SPH-DEM-FEM Method

Geofluids ◽

10.1155/2020/6635378 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Bailong Li ◽

Changming Wang ◽

Yanying Li ◽

Yiao Liu ◽

Nan Jiang ◽

...

Keyword(s):

Dynamic Response ◽

Debris Flow ◽

Impact Force ◽

Time History ◽

Impact Behavior ◽

Response Analysis ◽

Two Phase ◽

Fem Method ◽

Solid Liquid ◽

Based on the coupled SPH-DEM-FEM numerical method, this paper analyzes the dynamic interaction of solid debris flow particle-liquid debris flow slurry-retaining dam in order to explore the dynamic response of retaining dam under the impact of the solid-liquid two-phase debris flow and delves into the process of the debris flow impact on the dam, the impact force of debris flow, and the elastic-plastic time-history characteristics of the dam under different slopes of trapezoidal grooves. The calculation results show that the coupled SPH-DEM-FEM method can vividly simulate the impact behavior of the solid-liquid two-phase debris flow on the dam, reproduce the impact, climbing, and siltation in the process of the debris flow impact; the dynamic time-history curve of the retaining dam is consistent with the law of the literature, and the result of the debris flow impact force obtained is close to that of the empirical formula. Moreover, this paper studies the impact force distribution of the debris flow impact process. The results have a certain reference value for the study of the dynamic response of the retaining dam under the impact of the solid-liquid two-phase debris flow and the engineering design of the debris flow-retaining dam.

Hailstone-induced dynamic responses of pretensioned umbrella membrane structure

Advances in Structural Engineering ◽

10.1177/1369433220940149 ◽

2020 ◽

Vol 24 (1) ◽

pp. 3-16 ◽

Cited By ~ 5

Author(s):

Changjiang Liu ◽

Fan Wang ◽

Xiaowei Deng ◽

Song Pang ◽

Jian Liu ◽

...

Keyword(s):

Dynamic Response ◽

Membrane Structure ◽

Impact Analysis ◽

Impact Load ◽

Dynamic Responses ◽

Flexible Structure ◽

Membrane Material ◽

Membrane Structures ◽

Characteristic Points ◽

The membrane structure is a flexible structure, which is easy to vibrate or even relax under dynamic load. Engineering accident analysis shows that the relaxation of membrane structure is more likely to lead to structural failure. In this article, the impact load problem is combined with the flexible structure to analyze the impact of hailstone impact load on the dynamic response of membrane structure. First, the umbrella membrane stretching device was designed and manufactured, and the hailstone impact test was carried out on the umbrella membrane structure with polyvinyl chloride membrane material. Dynamic response data, tension relaxation of side cables and vibration deformation of umbrella membrane structures impacted by hailstones with different sizes and different characteristic points were obtained. In the numerical analysis, the form-finding analysis of umbrella membrane structure is carried out by finite element method, and the transient impact analysis is conducted in LS-DYNA. Finally, the reliability of the research results is verified by comparing the numerical and experimental results. The general laws and conclusions are drawn and the disaster-causing mechanism of membrane structure impacted by hailstone is revealed. On the whole, although the probability of hailstone destroying the membrane material directly is very small, it will relax the membrane structure and affect the safety of membrane structure. The conclusions of this article provide a theoretical basis for the design and maintenance of membrane structures.

Dynamic Response Analysis under the Metro-Vibration Loading of Xi'an Bell Tower Timber Structure

10.4028/www.scientific.net/amm.170-173.1361 ◽

2012 ◽

Vol 170-173 ◽

pp. 1361-1366 ◽

Cited By ~ 2

Author(s):

Zhao Bo Meng ◽

Teng Fei Zhao ◽

Shi Cai Cui ◽

Jie Jin

Keyword(s):

Dynamic Response ◽

Technical Specification ◽

Time History ◽

Response Analysis ◽

Winkler Foundation ◽

Analysis Model ◽

Time Dynamic ◽

Bell Tower ◽

Vibration Loading ◽

Taking Xi’an Bell Tower and metro line 2 as research background, at first, according to the theory of Euler-Bernoulli beam in Winkler foundation, the analysis model of train-track-foundation system was established, and then, time-history curve of metro-induced loading acts on tunnel structure is obtained by using Matlab produce platform. Secondly, two-dimensional finite element model of the structure-soil-tunnel interaction model was established using ANSYS. Taken loading time delay into consideration for the first time, dynamic response law of the bell tower under the metro-vibration loading is obtained. Finally, the impact of metro line 2 on Xi’an Bell Tower was evaluated according to the Technical specification for protection of historic buildings against man-made vibration.

Analysis of Solid T-Pier Dynamic Response to Debris Flow

10.4028/www.scientific.net/amm.744-746.739 ◽

2015 ◽

Vol 744-746 ◽

pp. 739-743

Author(s):

Zhen Yu Xiu ◽

Ming Jie Zhang ◽

Chen Zhang ◽

Yu Hong

Keyword(s):

Finite Element Method ◽

Finite Element ◽

Dynamic Response ◽

Debris Flow ◽

Stress And Strain ◽

Impact Action ◽

The Impact ◽

Element Method

In recent years, traffic lines are rapidly thrusting into the hilly regions[1]. It’s not hard to list such cases that bridges have been damaged by mud-rock flow. In this paper, it is studied that the dynamic response of the solid T-pier to mud-rock flow. a finite element method is applied to analyse the effects of the stress and strain of an T-pier under the impact action of mud-rock flow with different velocity.

Study on the Dynamic Response Characteristics of Cylindrical Coal-Rock Samples under Dynamic Loads

Shock and Vibration ◽

10.1155/2020/8820316 ◽

2020 ◽

Vol 2020 ◽

pp. 1-12

Author(s):

Hongqing Zhu ◽

Shuhao Fang ◽

Yilong Zhang ◽

Yan Wu

Keyword(s):

Dynamic Response ◽

Linear Relationship ◽

Rock Sample ◽

Axial Stress ◽

Stress And Strain ◽

Rock Samples ◽

Response Characteristics ◽

Coal Rock ◽

Dynamic Response Characteristics ◽

To research the dynamic response characteristics of cylindrical coal-rock samples under impact loads, the impact of rigid bars on cylindrical coal-rock samples is simulated under different speed conditions, based on LS-DYNA software, and the dynamic distribution characteristics of the stress, strain, and energy of cylindrical coal-rock samples are analyzed. The results demonstrated the following: (1) the cylindrical coal-rock sample failed at the center first, and the damage developed downward along the axial direction. (2) The critical effective stress and strain have an exponential function relationship with the velocity, and the critical time has a linear relationship with the velocity. (3) The energy change law of the cylindrical coal-rock sample is consistent with the destruction morphology. (4) The axial stress peaks in the severe damage part have a linear relationship with the speed, the axial stress attenuates rapidly after passing the stress yield point, and the axial strain does not increase continuously. (5) The peaks stress and strain on the central axis and the radial line obey the power function distribution, the axial stress produces tensile stress in the axial propagation direction, and the axial stress and strain peaks at the same position are larger than those of the radial stress and strain peaks. This research provides a reference for studying coal and rock dynamic disasters.