A repeated drop-weight impact testing apparatus for concrete

1988 ◽  
Vol 40 (144) ◽  
pp. 167-176 ◽  
Author(s):  
B. Barr ◽  
A. Baghli
Author(s):  
N Nasir Hussain ◽  
Srinivasa Prakash Regalla ◽  
Yendluri V Daseswara Rao ◽  
Tatacipta Dirgantara ◽  
Leonardo Gunawan ◽  
...  

There is an ever-increasing demand in the automotive sector to continuously improve the performance and reduce cost through weight reduction in the structure of the vehicle. In the present scenario, it is also necessary to meet the standards set by crash safety regulating authorities in various parts of the world. In automobiles, the crash box is placed in the anterior region to absorb the impact energy in the event of an accident. Glass fiber reinforced plastic crash boxes have a high strength-to-weight ratio and also are good in energy absorption, particularly useful in this scenario. In this paper, the effectiveness of different triggers in combination with various geometries is investigated for Glass fiber reinforced plastic crash boxes using drop-weight impact testing. A trigger is a geometric irregularity introduced in the crash box design to alter the energy as well as force levels by modifying the deformation mode under loading. Comparison of change in force level, absorption of impact energy, specific energy absorption values was performed for composite crash boxes made of various types of cross-sectional geometries along with multiple patterns of triggers. Force versus displacement (F–D) curves are drawn for all the cases of the glass fiber reinforced plastic crash boxes to understand the behavior of each combination formed with various types of geometries and triggers, under impact loading. Strength-to-weight ratio was considered as the deciding factor for the comparisons to know the best and worst cases of the crash boxes made of different cross-sections along with various trigger types. This study provides detailed insights into the drop-weight impact testing procedure including the preparation of specimens, setting up the drop-weight impact test, preparation of specimen clamps, safety precautions involved, data acquisition from the test and its processing.


1983 ◽  
Vol 5 (1) ◽  
pp. 4 ◽  
Author(s):  
WW Feng ◽  
KL Reifsnider ◽  
GP Sendeckyj ◽  
TT Chiao ◽  
PL Lien ◽  
...  

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Xiwu Zhou ◽  
Xiangyu Wang ◽  
Runcheng Zhang ◽  
Wen Zhang

In this study, two groups of RC beams were subjected to low-speed drop weight impact test by using the domestic advanced ultrahigh heavy-duty drop weight impact testing machine system. The main aspects studied are the influence of the combination of different impact velocity and mass on the dynamic response and local and global damage change of RC beam under the same impact energy. Next, the numerical model considering material strain rate is established using ABAQUS finite element software to verify and expand the experimental results. The results show the following: (1) under the condition of equal energy, the peak value of impact force measured in this experiment increases with the increase of impact velocity, yet the mid span displacement and rebar strain first increase and then decrease. In addition, when the impact velocity is 2.25 m/s and the impact mass is 400 kg, the beam has the most serious damage; (2) compared with the mass, the impact velocity has more obvious effects on the peak value of cumulative impact force, mid span displacement, and rebar strain; (3) with the decrease of the impact velocity (the increase of the mass), the local damage of the beam is gradually weakened and the overall damage is gradually exacerbated. The failure mode of the beam is transformed from local punching shear failure to overall static failure type.


2019 ◽  
Vol 168 ◽  
pp. 166-174 ◽  
Author(s):  
Ariff Farhan Mohd Nor ◽  
Mohamed Thariq Hameed Sultan ◽  
Mohammad Jawaid ◽  
Ahmad Mustafa Rayney Azmi ◽  
Ain Umaira Md Shah

Author(s):  
J. Allemand ◽  
M. R. Shortis ◽  
M. K. Elmouttie

Estimation of rock breakage characteristics plays an important role in optimising various industrial and mining processes used for rock comminution. Although little research has been undertaken into 3D photogrammetric measurement of the progeny kinematics, there is promising potential to improve the efficacy of rock breakage characterisation. In this study, the observation of progeny kinematics was conducted using a high speed, stereo videometric system based on laboratory experiments with a drop weight impact testing system. By manually tracking individual progeny through the captured video sequences, observed progeny coordinates can be used to determine 3D trajectories and velocities, supporting the idea that high speed video can be used for rock breakage characterisation purposes. An analysis of the results showed that the high speed videometric system successfully observed progeny trajectories and showed clear projection of the progeny away from the impact location. Velocities of the progeny could also be determined based on the trajectories and the video frame rate. These results were obtained despite the limitations of the photogrammetric system and experiment processes observed in this study. Accordingly there is sufficient evidence to conclude that high speed videometric systems are capable of observing progeny kinematics from drop weight impact tests. With further optimisation of the systems and processes used, there is potential for improving the efficacy of rock breakage characterisation from measurements with high speed videometric systems.


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