An analytical model for dynamic response of geosynthetic reinforced embankment system under traffic load

2022 ◽  
Vol 142 ◽  
pp. 104555
Author(s):  
Ru-Yi Hou ◽  
Jun-Jie Zheng ◽  
Hao Fang ◽  
Lingyun You
Keyword(s):  
Dynamic Response ◽  
Analytical Model ◽  
Traffic Load

DYNAMIC BEHAVIOR OF TELESCOPIC CRANES BOOM

2013 ◽  
Vol 13 (01) ◽  
pp. 1350010 ◽  
Author(s):  
IOANNIS G. RAFTOYIANNIS ◽  
GEORGE T. MICHALTSOS
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Dynamic Behavior ◽  
Analytical Model ◽  
Constant Velocity ◽  
Steel Beam ◽  
Continuum Approach ◽  
Theoretical Formulation ◽  
Modal Superposition ◽  
Superposition Technique

Telescopic cranes are usually steel beam systems carrying a load at the tip while comprising at least one constant and one moving part. In this work, an analytical model suitable for the dynamic analysis of telescopic cranes boom is presented. The system considered herein is composed — without losing generality — of two beams. The first one is a jut-out beam on which a variable in time force is moving with constant velocity and the second one is a cantilever with length varying in time that is subjected to its self-weight and a force at the tip also changing with time. As a result, the eigenfrequencies and modal shapes of the second beam are also varying in time. The theoretical formulation is based on a continuum approach employing the modal superposition technique. Various cases of telescopic cranes boom are studied and the analytical results obtained in this work are tabulated in the form of dynamic response diagrams.

Automated structural assessment of existing reinforced concrete underpasses

2021 ◽  
Author(s):  
Danny Jilissen ◽  
Rob Vergoossen ◽  
Yuguang Yang ◽  
Eva Lantsoght
Keyword(s):  
Reinforced Concrete ◽  
The Netherlands ◽  
Analytical Model ◽  
Load Distribution ◽  
Traffic Load ◽  
Sensitivity Analyses ◽  
Fem Model ◽  
Structural Assessment ◽  
Model Code ◽  
Model Code 2010

<p>Due to the large number of underpasses in the Netherlands that have to be assessed, a project at the Delft University of Technology in cooperation with Royal HaskoningDHV was started. Research was conducted into the automation of the structural assessment of existing reinforced concrete underpasses in the Netherlands. The developed Automated Structural Assessment Tool (ASA Tool) consists of an analytical model and a 2.5D FEM model. The analytical model uses traffic load distribution following the Guyon-Massonnet-Bares method for bending and a method based on <i>fib </i>Model Code 2010 for shear. The script-based 2.5D FEM model uses 2D shell elements and performs a linear elastic analysis. The input and output can be linked to a database for assessment of large batches. Sensitivity analyses showed that in-plane load distribution following <i>fib </i>Model Code 2010 combined with vertical load distribution according to EN 1991-2:2003 results in underestimated shear forces.</p>

scholarly journals 4D Printing of NiTi Auxetic Structure with Improved Ballistic Performance

Micromachines ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 745
Author(s):  
Hany Hassanin ◽  
Alessandro Abena ◽  
Mahmoud Ahmed Elsayed ◽  
Khamis Essa
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Analytical Model ◽  
Poisson’S Ratio ◽  
Poisson's Ratio ◽  
4D Printing ◽  
Auxetic Structures ◽  
Negative Poisson's Ratio ◽  
The Impact ◽  
Auxetic Structure

Auxetic structures have attracted attention in energy absorption applications owing to their improved shear modulus and enhanced resistance to indentation. On the other hand, four-dimensional (4D) printing is an emerging technology that is capable of 3D printing smart materials with additional functionality. This paper introduces the development of a NiTi negative-Poisson’s-ratio structure with superelasticity/shape memory capabilities for improved ballistic applications. An analytical model was initially used to optimize the geometrical parameters of a re-entrant auxetic structure. It was found that the re-entrant auxetic structure with a cell angle of −30° produced the highest Poisson’s ratio of −2.089. The 4D printing process using a powder bed fusion system was used to fabricate the optimized NiTi auxetic structure. The measured negative Poisson’s ratio of the fabricated auxetic structure was found in agreement with both the analytical model and the finite element simulation. A finite element model was developed to simulate the dynamic response of the optimized auxetic NiTi structure subjected to different projectile speeds. Three stages of the impact process describing the penetration of the top plate, auxetic structure, and bottom plate have been identified. The results show that the optimized auxetic structures affect the dynamic response of the projectile by getting denser toward the impact location. This helped to improve the energy absorbed per unit mass of the NiTi auxetic structure to about two times higher than that of the solid NiTi plate and five times higher than that of the solid conventional steel plate.

Nonlinear Dynamic Response and Active Control of Piezoelastic Laminated Shallow Spherical Shells with Damage

2011 ◽  
Vol 21 (6) ◽  
pp. 783-809 ◽  
Author(s):  
Mao Yiqi ◽  
Fu Yiming ◽  
Tian Yanping
Keyword(s):  
Dynamic Response ◽  
Spherical Shell ◽  
Vibration Control ◽  
Analytical Model ◽  
Constitutive Relations ◽  
Collocation Point ◽  
Shallow Spherical Shell ◽  
Geometrical Parameters ◽  
Orthogonal Collocation ◽  
Spherical Shells

Based on Talreja’s damage model with tensor valued internal state variables and geometric nonlinear theory, the constitutive relations for a moderately thick shallow spherical shell with damage are derived. The distribution of electric potential along the thickness direction in the piezoelectric layer is simulated by a sinusoidal function, and accordingly the dynamic analytical model for the cross-ply laminated moderately thick piezoelectric shallow spherical shell is established. Using the negative velocity feedback control algorithm, an analytical model for active vibration control of the piezoelectric laminated moderately thick piezoelectric shallow spherical shell is built when the damage effect is considered. And the solutions to the whole problem are obtained with synthetical utilization of the orthogonal collocation point method and the Newark method. In numerical examples, the effects of damage, piezoelectric effect, and the structure’s geometrical parameters on the dynamic response and vibration control of the piezoelastic laminated shallow spherical shells with damage are investigated.

Soil–Structure–Wave Interaction of Gravity-Based Offshore Wind Turbines: An Analytical Model

2020 ◽  
Vol 143 (3) ◽  
Author(s):  
Dimitrios G. Pavlou
Keyword(s):  
Dynamic Response ◽  
Analytical Model ◽  
Wind Turbines ◽  
Initial Conditions ◽  
Offshore Wind ◽  
Design Parameters ◽  
Wave Loads ◽  
Wave Load ◽  
Offshore Wind Turbines ◽  
Dynamic Phenomena

Abstract The structural design of offshore wind turbines is based on the consideration of coupled dynamic phenomena. Wave loads cause the dynamic oscillation of the monopile, and the dynamic oscillation of the monopile affects the wave loads. The boundary conditions of the gravity-based foundation-monopile-turbine system are mostly affected by the flexural stiffness of the foundation plate, the elastic and creep behavior of the soil, and the inertia (translational and rotational) of the wind turbine mass. The design of the foundation should consider the dynamic response of the soil and the monopile, and the dynamic response of the soil and the monopile is affected by the design parameters of the foundation. The initial conditions of the system yield transient dynamic phenomena. A braking wave at t = 0 causes different dynamic response than the steady-state conditions due to a harmonic wave load. In the present work, an integrated analytical model simulating the above dynamic phenomena is proposed. With the aid of double integral transforms and generalized function properties, a solution of the corresponding differential equations for the monopile-soil-foundation system and the boundary and initial conditions is derived. A parametric study is carried out, and results of the effect of the design parameters and soil properties are presented and discussed.

scholarly journals A Simulation-Based Analysis of the Loss Process of Broadcast Packets in WAVE Vehicular Networks

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Salvador Gonzalez ◽  
Victor Ramos
Keyword(s):  
Analytical Model ◽  
Vehicular Networks ◽  
Loss Rate ◽  
Traffic Load ◽  
Analytical Models ◽  
Ieee 802.11P ◽  
Control Channel ◽  
Channel Switching ◽  
Loss Process ◽  
Hidden Terminal

The IEEE 802.11p standard operates with the WAVE (Wireless Access in Vehicular Environments) system in vehicular ad hoc networks (VANETs). The broadcast process is used to send messages for safety and non-safety applications. A previous work on broadcast packets over the control channel proposes an analytical model to study the loss process. Even if such work does not consider all of the phenomena affecting the operation of vehicular networks, we can obtain a very good approximation of the performance that VANETs may exhibit. Regardless of its importance, this subject has been barely studied. Moreover, there is in the literature only a couple of contributions on this subject, being both analytical models. Therefore, we present in this paper an analysis of the loss process of broadcast packets on the control channel of VANETs over different scenarios. First, we consider a typical two-way scenario and then we analyze a scenario with intersections, both for different vehicle densities. We conduct a campaign of extensive simulations with the NS-3 simulator to study the average loss rate of broadcast packets, and then we compare our results with an analytical model proposed by Campolo et al. We prove the relationship among the contention window, the packet size, and the number of vehicles with the loss rate, including losses caused by noise, collisions, hidden terminal, and channel switching. Thus, we analyze the loss process validating the results obtained by Campolo et al. We find that there are additional factors affecting the loss rate, which cannot be captured with the analytical model. One key finding in this work is that the loss rate due to channel switching differs between both approaches. Also, we find bounds on the use of the control channel, with the loss rate and the traffic load in the network as parameters.

Intelligent dynamic response of Guangxi marine soft foundation under traffic load

2019 ◽  
Vol 37 (4) ◽  
pp. 4811-4818
Author(s):  
Junhui Luo ◽  
Xianlin Liu ◽  
Decai Mi ◽  
Deqiang Chen ◽  
Zhifen He ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Traffic Load ◽  
Soft Foundation

Dynamic Characteristics of a Hydraulic Damper

2002 ◽  
Author(s):  
Vishnu Verma ◽  
A. K. Ghosh ◽  
H. S. Kushwaha
Keyword(s):  
Pressure Drop ◽  
Dynamic Response ◽  
Analytical Model ◽  
Dynamic Characteristics ◽  
System Parameters ◽  
Hydraulic Damper ◽  
Dynamic Excitation ◽  
Sinusoidal Motion ◽  
Bypass Line

The response of a structure to earthquake or any other dynamic excitation can be brought down by using a suitable damper such as a hydraulic damper. An analytical model has been developed for hydraulic damper, which consists of a cylinder and piston arrangement with a bypass pipeline. The stiffness of the system is primarily due to the compressibility of the fluid and the damping is largely due to the pressure drop in the bypass line. The dynamic response of the hydraulic damper has been evaluated for an assumed sinusoidal motion of the piston. The paper presents detailed results of the study of the dynamic response of the damper to variations in input and system parameters. The characteristics of the damper, thus obtained, will be useful in determining the dynamic response of the whole system to which this damper will be attached.

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