Behaviour of new LCR and ordinary prestressed concrete railway sleepers under repeated impact loads

2022 ◽  
Vol 319 ◽  
pp. 126151
Author(s):  
Ferhat Çeçen ◽  
Bekir Aktaş ◽  
Hakan Öztürk ◽  
M. Burhan Navdar ◽  
İrfan Ş. Öztürk
Keyword(s):  
Prestressed Concrete ◽  
Impact Loads ◽  
Repeated Impact

Mechanics Behavior Analysis on Laser Cladding under Repeated Impacting Load

2010 ◽  
Vol 154-155 ◽  
pp. 1100-1103
Author(s):  
Ru Shu Peng ◽  
De Wen Tang ◽  
Qiong Liu
Keyword(s):  
Behavior Analysis ◽  
Stress Wave ◽  
Laser Cladding ◽  
Impact Load ◽  
Joint Surface ◽  
Impact Loads ◽  
Repeated Impact ◽  
Hardness Change

On the property of repeated impact load, the attrition, hardening and plasticity warp of the laser cladding sampling were researched by using stress wave spread theory. Results show that under repeated impact loads, stress wave occurs on the metallurgical joint surface of the coat and the basis, forming stretch wave that causes coat slitting and angle splitting. The micro-pits failure and deep exfoliation occur on the coat surface because of the stress centralization. The accumulation of impact load energy cause hardness change and plasticity warp.

Experimental and Numerical Investigation of Aluminum Alloy Plates With Initial Crack Under Repeated Dynamic Impact Loads

2018 ◽  
Author(s):  
Fangjuan Duan ◽  
Weiguang Liu ◽  
De Xie ◽  
Jingxi Liu ◽  
Zhiqiang Hu
Keyword(s):  
Aluminum Alloy ◽  
Numerical Simulations ◽  
Carrying Capacity ◽  
Initial Crack ◽  
Impact Loads ◽  
Load Carrying Capacity ◽  
Repeated Impact ◽  
Alloy Plate ◽  
Numerical Predictions ◽  
Load Carrying

Ships and offshore structures are often exposed to various types of repeated impact loads, such as wave slamming, floating ice impacts and ship collisions which will cause large deformation or even fracture. With imperfections due to the process of construction or damage caused by accidents, the load carrying capacity of structures will decrease. This paper investigates the load carrying capacity of aluminum alloy plate with an initial crack under repeated impact loads by means of experiments and numerical simulations. In the experiments, the prepared specimens with crack and without crack are impacted repeatedly up to plate perforation by releasing a hemispherical-headed cylindrical hammer. Numerical simulations are carried out with ABAQUS/Explicit software. The numerical models are built according to the actual experimental conditions. Comparison of the numerical predictions with the experimental results shows reasonable agreement. It is found that aluminum alloy plates under repeated impacts are sensitive to initial cracks. The fracture mode and plastic deformation of aluminum alloy plates can also be affected.

Impact Damage and Residual Strength of Composite Joints in Car Bodies

2013 ◽  
Author(s):  
Juanjuan Sun ◽  
Lingyu Sun ◽  
Junmin Du ◽  
Taikun Wang
Keyword(s):  
Residual Strength ◽  
Impact Damage ◽  
Design Method ◽  
Prediction Method ◽  
Impact Loads ◽  
Composite Joints ◽  
Repeated Impact ◽  
Reinforced Plastics ◽  
Bending Modulus ◽  
Initial Modulus

With the weight reduction requirements for vehicles and the cost reduction tendency for carbon fibers, carbon fiber reinforced plastics (CFRPs) will be applied more and more in automobile bodies in place of some steel materials. However, the structural design method using CFRPs is much different from that using steel. For example, the anisotropic material properties and the brittle plastics matrix need to be considered, and the connection between components is through adhesive joints, which is possibly weaker than the traditional spot welding. These features make CFRPs sensitive to impact loads, especially the repeated low-energy impact. This paper presents a damage-based residual modulus and strength prediction method, which may be utilized in the design of composites components subject to repeated impact loads. First, the CFRPs samples were impacted repeatedly by the pendulum hammer at a constant kinetic energy, 2J, and then, the residual bending modulus and strength were measured by static three-point bending machine. According to the test data, the relationship between impact number and residual stiffness and residual strength were established, and the damage factors after each impact were calculated. In subsequent numerical simulation, the damage accumulation effect was included in the one-step prediction model through replacing the initial modulus by the degradation modulus, and this method was verified numerically by comparison with N-step prediction results after N-times impact calculations. Finally, two kinds of composite joints were analyzed numerically, which provides theoretical guide for the design of composite joints in automobile body.

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