Papers by Keyword: Collision

Paper TitlePage

Authors: Yue Feng Yang, Chun An Tang, Zheng Zhao Liang, Zhi Yi Liao
Abstract: Based on dynamic contact force and FEM, the contact – separation process of collision was investigated. Compared with other methods, the dynamic contact method needn’t modify the general stiffness matrix, and increase any additional iterative computation. So there should be less computation and high efficiency. By building simulation model LECEI(the technique of loading edge cracks by edge impact), the propagation of branching cracks were simulated. Compared with existing research results, the method can be suitable to the impact model such as LECEI.
1423
Authors: Guo Ming Hu, Li Ping Liu, Hui Wan, Yu Liu
Abstract: Aimed principally at increasing the impact velocity of the particle assuming a given circumferential velocity and to achieve collinear collision of particles by a mechanical method with a consideration on energy saving for comminution, a prototype dual cone impact mill was designed and built. This dual cone impact mill mainly consists of two cone disks with the same geometrical dimensions, and the same rotational speeds rotating in opposite directions. There are no grinding media in the dual cone impact mill. The dependence of the comminution effect on two parameters, cone disk speed and air flow rate, was experimentally investigated. The results obtained from grinding quartz and cement clinker indicate that this prototype mill can be used for grinding materials of Mohs hardness up to of 6-7, while achieving mean particle sizes of 10  m.
1150
Authors: Stelian Alaci, Florina Carmen Ciornei, Constantin Filote, Ionuţ Cristian Românu
Abstract: The paper presents the analysis of plastic indentations resulting after the impact between a steel ball and a disc made of mild steel, rotating about a vertical axis. The imprints are analysed using a laser scanner, the profiles of the mark, in normal and tangent section about the impact point radius, being relevant. It is shown that the use of parabolas is sufficient to approximate the profiles of the imprint. The profiles from the two sections are interpolated and then brought for comparison into the same coordinate system. Finally, the curvature radii of the profiles from the two sections are found and the remark that increasing the angular speed of the disc presents opposite effects to the curvature radius in the two sections.
223
Authors: Jian Min Zhang, Zheng Guo Yuan, Ying Ping Wu
Abstract: Long-span bridge across the river in cold areas, is often impacted by the drift ice in spring, thus having some severe effects on the stability and vibration of the bridge structure. With a long-span prestressed concrete T-rigid frame bridge as studied object, based on the display analysis function of the LS-DYNA software, this paper represents the simulating process of the contact and collision between the drift-ice and T-rigid frame bridge pier, and the influence of various factors was analyzed, such as model boundary condition, contact types of river ice and pier, algorithm and element connection transition area. Thus the reasonable calculation model of the collision force caused by drift-ice to pier was determined. The result has important theoretical and practical value to ensure the safety of the bridge in cold area, as well as to reduce the project cost.
17
Authors: Lian Long Yan, Zhi Hua Chen
Abstract: In this paper, RFID anti-collision ALOHA algorithm this paper proposed an improved algorithm for dynamic ALOHA scheme, which can improve the performance of RFID anti-collision system.
2131
Authors: Zheng Hao Ge, Wei Huang, Wei Hua Liu, Zhi Heng Zhai
Abstract: This paper takes the parallel indexing cam mechanism as research object and analyzes the formation of the profile of cam. On the basis of Visual C++6.0 object-oriented method, we have successfully developed the CAD/CAE/CAM system of parallel indexing cam mechanisms, which provides the parameter input dialogue frame with friendly interface. We can generate accurate profile data by using it, then create the three-dimensional model of the parallel indexing cam and assemble it with other parts under the Pro/E environment. At last, we don’t build virtual prototype until we transform the model into ADAMS through special interface Mechanism/Pro. Finally, this paper has researched the theory of contact and collision, carries out the motion simulation. We have received many valuable conclusions of practical application through all of the process.
475
Authors: Jin Tian Wang, Shu Ying Qu, Xing Min Hou, Ao Tian Ju
Abstract: Collisions between over-high trucks and protection frame for height limit happen frequently, which seriously destroyed the railway infrastructure and affected the road traffic safety. Based on nonlinear software ANSYS/LS-DYNA, the collision process of over-high trucks and protection frame is simulated, and the failure mechanism of protection frame is analyzed respectively from deformation, stress, load etc. Load analysis results indicate that the maximum impact force is approximately direct proportional to the initial velocity, which can be used for choosing the collision load in the design. Stress analysis results indicate that the maximum stress usually occurs in the protection frame crossbar and joint area. Adding the diagonal bracing or increasing the crossbar thickness are the effective methods to improve the impact resistance capability of the protection frame.
1967
Authors: Yehia Abdel Nasser, Aly Aliraqi, Bader El Din Ali
Abstract: Structural design of ships against collision requires prediction of the extent of damage to stiffened plates subjected to impact. In ship structures, stiffened plates are furnished with vertical or horizontal stiffeners to sustain conventional loads such as shearing, bending and local buckling. The consideration of collision in ship structural design is especially important for tankers where accidents may cause serious environmental pollution. In predicting the extent of collision damage, FE modeling of stiffened plates using ABAQUS software is applied to demonstrate different collision scenario. Typical stiffened plates of tankers in service with different configurations of stiffeners are used to examine absorbed energy in each case. The aim of this paper is to examine the stiffener shape that absorbs more deformation energy.
119
Authors: Ying Guo, Yu Tao Liu
Abstract: To synchronize nodes’ time in mobile underwater sensor networks, a collision based time synchronization scheme called “Coll-Sync” is proposed, which is a novel time synchronization approach for underwater acoustic environment. Collision has been identified as a major challenge to communication, and current systems implement sophisticated solutions to detect and avoid it. Coll-Sync shows that collision contains highly useful information that can be leveraged to improve time synchronization greatly. It is the first time synchronization algorithm that does not suffer but benefit from collision in underwater acoustic channel. Simulation results show that Coll-Sync has high precision and low energy cost. It significantly outperforms existing time synchronization schemes.
806
Authors: Yong Qiang Yang, Li Li Xie
Abstract: In order to solve the problem of collision in engineering field, the dynamic equation of collision system was established based on FEM(finite element method) and contact element model. The present method can account for the influence of the nonlinear contact stiffness as well as the energy loss during collision process. Collision had been simulated using FEM and MSM(mode superposition method) separately with various contact stiffness, sphere masses and impact velocities. The results indicate that FEM can be used to solve the problem of collision. The two groups of time history curves of contact load have almost the same shape. Compared with the results by MSM, collision durations are relatively decreased by about 7%, and difference of peak value is no more than 4%. The method can be used for collision between two complex structures with nonlinear reaction. So, it has a wider application to simulation of collision damage in engineering field.
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