STUDY ON THE ASSESSMENT OF IMPACT FORCE BETWEEN SHIP AND BRIDGE PIER

2021 ◽  
Vol 161 (A4) ◽  
Author(s):  
J Pan ◽  
S W Huang ◽  
Y F Huang ◽  
M C Xu
Keyword(s):  
Impact Force ◽  
Bridge Pier ◽  
Bulk Carrier ◽  
Explicit Finite Element ◽  
Collision Response ◽  
The Difference ◽  
Bridge Crossing ◽  
Collision Force ◽  
Comparison Of The Results ◽  
The Impact

The bridge crossing water way is in the risk of impact by vessel, and thus it is very important to estimate the collision force for the safety of bridge. The impact force between bridge pier and vessel is investigated by numerical simulation and various empirical formulae. The collision response between a 5000t DWT bulk carrier with bulb bow and rigid bridge pier is simulated in the explicit finite element code of ANSYS LS-DYNA. The difference of the impact force between the empirical formulae and FE analysis are discussed. Based on the comparison of the results, the coefficient in the formulae is suggested for obtaining more accurate assessment of impact force.

Study on the Assessment of Impact Force Between Ship and Bridge Pier

2019 ◽  
Vol 161 (A4) ◽  
Keyword(s):  
Impact Force ◽  
Bridge Pier ◽  
Bulk Carrier ◽  
Explicit Finite Element ◽  
Collision Response ◽  
The Difference ◽  
Bridge Crossing ◽  
Collision Force ◽  
Comparison Of The Results ◽  
The Impact

The bridge crossing water way is in the risk of impact by vessel, and thus it is very important to estimate the collision force for the safety of bridge. The impact force between bridge pier and vessel is investigated by numerical simulation and various empirical formulae. The collision response between a 5000t DWT bulk carrier with bulb bow and rigid bridge pier is simulated in the explicit finite element code of ANSYS LS-DYNA. The difference of the impact force between the empirical formulae and FE analysis are discussed. Based on the comparison of the results, the coefficient in the formulae is suggested for obtaining more accurate assessment of impact force.

Numerical Study on the Dynamical Characteristic and Impact Force Between Vessel With Rake Bow and Bridge Pier

2019 ◽  
Author(s):  
Ming Cai Xu ◽  
Zi Xuan Zhang ◽  
Xiao Qiang Zhang ◽  
Jin Pan ◽  
Yi Fei Huang
Keyword(s):  
Impact Force ◽  
Numerical Study ◽  
Structural Response ◽  
Bridge Pier ◽  
Quadratic Growth ◽  
Economic Losses ◽  
Dynamical Characteristic ◽  
Growth Trend ◽  
Collision Force ◽  
The Impact

Abstract The possibility of collisions between vessels and bridges has an unavoidable increase, which may cause significant economic losses and sometimes even casualties. The finite element method is used to simulate the impact process between the vessel with raked bow and bridge pier. The influence of parameter on the structural response and impact force is discussed, including the impact velocity, angle, mass of vessel, and the shape of bridge. The relationship of collision force and energy of impact vessel is investigated. It is found that the collision energy shows a quadratic growth trend with the increase of vessel velocity.

Analysis on the Impact Force of a Ship Colliding with a Bridge Pier

2012 ◽  
Vol 193-194 ◽  
pp. 693-701
Author(s):  
Jian Guo Ding ◽  
Zhi Qiao
Keyword(s):  
Mechanical Model ◽  
Mass Velocity ◽  
Impact Force ◽  
Impact Angle ◽  
Bridge Pier ◽  
Velocity Coefficient ◽  
The Impact

Because many accidents in China involve a ship in a barge fleet colliding with a bridge pier, determining the impact force of the ship is important. To obtain an equation that describes the impact force of a ship colliding with a bridge pier, a mechanical model of the collision is simplified, and the results from other researchers are applied. Based on the equation, it is found that the impact force of a ship colliding with a bridge pier is not only relevant to the mass，velocity, board thicknesses of the ship, and the impact angle, but also to the remaining velocity coefficient. It has been demonstrated that the result from the proposed equation in this paper is in accordance with that of Gkss’s test in Wosin G theory.

Numerical Simulations of the Drifting Ice Sheets Collision with the Bridge Pier

2013 ◽  
Vol 368-370 ◽  
pp. 1383-1386
Author(s):  
Lian Zhen Zhang ◽  
Wei Xiong
Keyword(s):  
Numerical Simulations ◽  
Ice Sheets ◽  
Ice Sheet ◽  
Time History ◽  
Material Model ◽  
Bridge Pier ◽  
Bridge Design ◽  
Drifting Ice ◽  
Collision Force ◽  
The Impact

The drifting ice sheets impact with the bridge pier and other hydraulic structures in the rivers, which may damage even cause collapse of the structures. In this paper, the FEM software package LS-DYNA was used to performed the numerical simulations of the collision process of the ice sheets and the bridge piers to make clear the interaction between them and to understand the failure mechanism of the ice sheet. The elastic strain-stress model with von mises failure criterion was used to describe the ice material. The brittle damage material model was used to describe the concrete pier. Three types thickness of ice sheets were performed at various velocity of the ice sheet respectively. The impact process of every case were displayed and the time history curve of the collision force were given out. The simulations results show that the peak value of the collision force time history curve increases with the velocity of the sheet firstly and then decreases with the velocity of the ice sheet. There is one critical velocity which relate to the compressive strength of the ice sheet. The simulation result were also compared with the different bridge design code, which show that the code result is more conservative in bridge design.

Initial response mechanism and local contact stiffness analysis of the floating two-stage buffer collision-prevention system under ship colliding

2021 ◽  
pp. 136943322098610
Author(s):  
Kai Lu ◽  
Xu-Jun Chen ◽  
Zhen Gao ◽  
Liang-Yu Cheng ◽  
Guang-Huai Wu
Keyword(s):  
Kinetic Energy ◽  
Impact Force ◽  
Contact Stiffness ◽  
Impact Angle ◽  
Bridge Pier ◽  
Two Stage ◽  
Collision Prevention ◽  
Prevention System ◽  
The Impact ◽  
Depth Curves

A floating two-stage buffer collision-prevention system (FTBCPS) has been proposed to reduce the impact loads on the bridge pier in this paper. The anti-collision process can be mainly divided into two stages. First, reduce the ship velocity and change the ship initial moving direction with the stretching and fracture of the polyester ropes. Second, consume the ship kinetic energy with the huge damage and deformation of the FTBCPS and the ship. The main feature of the FTBCPS lies in the first stage and most of the ship kinetic energy can be dissipated before the ship directly impacts on the bridge pier. The contact stiffness value between the ship and the FTBCPS can be a significant factor in the first stage and the calculation method of it is the focus of this paper. The contact force, the internal force and the general equation of motion have been given in the first part. The structure model of the ship and the FTBCPS are then established in the ANSYS Workbench. After that, 38 typical load cases of the ship impacting on the FTBCPS are conducted in LS-DYNA. The reduction processes of the ship kinetic energy and the ship velocity in different load cases have been investigated. It can be summarized that the impact angle and the ship initial velocity are the main factors in the energy and velocity dissipation process. Moreover, the local impact force-depth curves have also been studied and the impact angle is found to be the only significant factor on the ship impact process. Next, the impact force-depth curves with different impact angles are fitted and the contact stiffness values are accordingly calculated. Finally, the impact depth range, the validity of the local simulation results and the consistency of the fitted stiffness value are verified respectively, demonstrating that the fitted stiffness values are applicable in the global analysis.

scholarly journals Finite Element Simulation of the Vibration Provided by Sandwich Rigid Panel with a Resilient Material In Between under Heavyweight Impact

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Shun-Fa Hwang ◽  
Chao-Wen Chen ◽  
Sung-Chin Chung ◽  
Yaw-Shyan Tsay
Keyword(s):  
Finite Element ◽  
Impact Force ◽  
Impact Behavior ◽  
Sound Insulation ◽  
Explicit Finite Element ◽  
Element Simulation ◽  
Rubber Model ◽  
Two Parameters ◽  
The Impact ◽  
Impact Vibration

The purpose of the present work is to use an explicit finite element code to model the impact behavior of a heavyweight impact source like rubber ball and to predict the floor impact vibration of resilient materials, which are used in the floor coverings construction for sound insulation. To simulate the impact force of rubber balls, the hyperviscoelastic rubber model is applied. Then, this rubber model is used in the simulation for the impact vibration of resilient materials. The results indicate that the hyperviscoelastic rubber model could precisely simulate the impact force of rubber balls, as its two parameters are properly chosen according to the desired impact force. Also, the present model could capture the impact and vibration behavior of the considered materials and reasonably evaluate the insulation effect of resilient materials.

Investigating the influence of Taekwondo body protectors size on shock absorption

2020 ◽  
pp. 1-9
Author(s):  
Hee Seong Jeong ◽  
Sae Yong Lee ◽  
Hyung Jun Noh ◽  
David Michael O’Sullivan ◽  
Young Rim Lee
Keyword(s):  
Impact Strength ◽  
Impact Force ◽  
Impact Load ◽  
The Body ◽  
Shock Absorption ◽  
Significance Level ◽  
The Difference ◽  
Maximum Impact Force ◽  
Impact Energies ◽  
The Impact

OBJECTIVE: This study aims to compare and analyze the difference of impact force attenuation according to size and impact location on a Taekwondo body protector. METHODS: Body protectors sized 1 to 5, were impact tested by equipment based on the specifications in the European standard manual (EN 13277-1, 3). The impactor release heights were set to match impact energies of 3 and 15 J. The impactor was made from a 2.5 kg cylindrically cut piece of aluminum. Each body protector was impacted 10 times at the two impact energies and two locations. The differences in performance for each body protector size were compared using a two-way analysis of variance with a significance level of p< 005. The effect sizes were investigated using a partial eta squared value (η2). RESULTS: The significant mean differences between the body protector size and impact area (p< 005) and the average impact time of impact strengths 3 and 15 J were 0.0017 and 0.0012 s, respectively In addition, when an impact strength of 15 J was applied, the maximum resulting impact force exceeded 2000 N for both locations on all sizes. Furthermore, at an impact strength of 3 J size 3 significantly reduced the impact force more than the other sizes; however, size 1 showed the greatest shock absorption at an impact of 15 J. CONCLUSION: The results of this study show that the shock absorption of body protectors does not increase according to size; i.e., a larger body protector does not reduce the impact load more effectively. To improve safety performance, we recommend a maximum impact force of 2000 N or less for all body protectors.

A Comparative Study of the Dissipative Contact Force Models for Collision Under External Spring Forces

2018 ◽  
Vol 13 (10) ◽  
Author(s):  
Dong Xiang ◽  
Yinhua Shen ◽  
Yaozhong Wei ◽  
Mengxing You
Keyword(s):  
Energy Loss ◽  
Comparative Study ◽  
Contact Force ◽  
Multibody Systems ◽  
Force Model ◽  
Collision Response ◽  
Order Of Magnitude ◽  
The Difference ◽  
Comparative Results ◽  
The Impact

The dissipative contact force model plays a key role in predicting the response of multibody mechanical systems. Contact-impact event can frequently take place in multibody systems and the impact pair is often affected by supporting forces which are treated as external spring forces. However, the external spring forces are ignored during the derivation process of existing dissipative contact force models. Considering the influences of external spring forces, the fact is discussed that the crucial issues, including relative velocity and energy loss, in modeling dissipative contact force are different compared to the same issues analyzed in existing literatures. These differences can result in obvious errors in describing the collision response in multibody systems. Thus, a comparative study is carried out for examining the performances of several popular dissipative contact force models in multibody dynamics. For this comparison, a method associated with Newton's method is proposed to calculate the contact force that meets the Strong's law of energy loss and this force is used as reference. The comparative results show that the models suitable for both hard and soft contact exhibit good accuracy when contact equivalent stiffness is far larger than external spring stiffness by two orders of magnitude. Conversely, these models can cause varying degree and obvious errors in contact force, number of collisions, etc., especially when the difference in stiffness is close to or less than one order of magnitude.

Numerical analysis of collision between a tractor-trailer and bridge pier

2018 ◽  
Vol 9 (4) ◽  
pp. 484-503 ◽  
Author(s):  
Luwei Chen ◽  
Hao Wu ◽  
Qin Fang ◽  
Tao Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Impact Force ◽  
Element Model ◽  
Bridge Pier ◽  
Bridge Piers ◽  
Highway Bridge ◽  
Heavy Duty ◽  
The Impact ◽  
The Finite Element Model

Accidents involving collisions of heavy-duty trucks with highway bridge piers occurred occasionally, in which the bridge piers might be subjected to severe damage, and cause the collapse of the superstructure due to the loss of axial loading capacity. The existing researches are mostly concentrated on the light- or medium-duty trucks. This article mainly concerns about the collisions between the heavy-duty trucks (e.g. tractor-trailer) and bridge piers as well as the evaluation of the impact force. First, by modifying the finite element model of Ford F800 single-unit truck, which was developed by National Crash Analysis Center, the finite element model of a tractor-trailer is established. Then, the full-scale tractor-trailer crash test on concrete-filled steel pier jointly conducted by Texas Transportation Institute, Federal Highway Administration, and Texas Department of Transportation is numerically simulated. The impact process is well reproduced and the established model is validated by comparison of the impact force. It indicates that the tractor-trailer impact force time history consists of two or three peaks and the corresponding causes are revealed. Furthermore, the parametric influences on the impact force are discussed, including the diameter and cross section shape of the pier, cargo weight, impact velocity, relative impact position, and vehicle type. Finally, the finite element model of an actual reinforced concrete highway bridge pier is established, and the impact force and lateral displacement of the pier subjected to the impact of the tractor-trailer are numerically derived and discussed.

scholarly journals On the issue of damping external loads of mine racks

2020 ◽  
pp. 532-541
Keyword(s):  
Impact Force ◽  
Mining Industry ◽  
Compressive Force ◽  
Single Layer ◽  
Critical Force ◽  
Structural Scheme ◽  
Main Bearing ◽  
The Difference ◽  
The Impact ◽  
External Loads

The vulnerability of the main structural elements of rock liningsto external short-term and long-term loads is an important problem in the mining industry. The existing schemes are not designed for the simultaneous perception of compressive, shock and vibration influences. A way to solve this problem is to develop a new structural scheme of the racks, which are the linings' main bearing element. In the article, it is proposed to use multi-layer racks made as a rod covered with layers of plates.This will make it possible to use for damping external loads not only the pliability of the rack as a whole but also the frictional forces between its layers.The acting impact force will be decomposed into compressive and pressing forces. Due to the fact that the action of the external shock load is spent on moving and pressing the layers, its deformations are minimized compared to single-layer monolithic structures.For calculating the arising stresses, it is assumed that the rack plates are hinged at the edges, free along the length of the rack, and are under the joint action of compressive (stretching) forces and tangential forces evenly distributed on all sides of the plate.The article provides a rationale for the prospect of using such multi-layer racks and proposes an algorithm for calculating critical loads and stresses with the derivation of the damping coefficient. This coefficient is determined by the difference between the force of the shock wave and the critical load. The critical force, in turn, is calculated as the difference between the compressive force and the friction force between the layers, corrected for the part of the impact force, which causes stress close to critical in the dangerous middle section of the plate. By the value of the coefficient, it can be judged the effectiveness of the selected structural scheme of the rack.

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