scholarly journals The Mechanical and Reaction Behavior of PTFE/Al/Fe2O3 under Impact and Quasi-Static Compression

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Jun-yi Huang ◽  
Xiang Fang ◽  
Yu-chun Li ◽  
Bin Feng ◽  
Huai-xi Wang ◽  
...  
Keyword(s):  
High Speed ◽  
Xrd Analysis ◽  
High Speed Photography ◽  
Experimental Conditions ◽  
Static Compression ◽  
Reaction Behavior ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
Quasi Static Compression

Quasi-static compression and drop-weight test were used to characterize the mechanical and reaction behavior of PTFE/Al/Fe2O3 composites. Two kinds of PTFE/Al/Fe2O3 composites were prepared with different mass of PTFE, and the reaction phenomenon and stress-strain curves were recorded; the residuals after reaction were analyzed by X-ray diffraction (XRD). The results showed that, under quasi-static compression condition, the strength of the materials is increased (from 37.1 Mpa to 77.2 Mpa) with the increase of PTFE, and the reaction phenomenon occurred only in materials with high PTFE content. XRD analysis showed that the reaction between Al and Fe2O3 was not triggered with identical experimental conditions. In drop-weight tests, PTFE/Al/Fe2O3 specimens with low PTFE content were found to be more insensitive by high-speed photography, and a High Temperature Metal Slag Spray (HTMSS) phenomenon was observed in both kinds of PTFE/Al/Fe2O3 composites, indicating the existence of thermite reaction, which was confirmed by XRD. In PTFE/Al/Fe2O3 system, the reaction between PTFE and Al precedes the reaction between Al and Fe2O3.

scholarly journals Evaluation of Impact Resistance for Derailment Containment Provision Using Drop Weight Test

2020 ◽  
Vol 20 (5) ◽  
pp. 185-194
Author(s):  
NamHyuk Kim ◽  
YunSuk Kang ◽  
HyunUng Bae ◽  
KyungJu Kim ◽  
NamHyoung Lim
Keyword(s):  
High Speed ◽  
Impact Resistance ◽  
Impact Behavior ◽  
Human Errors ◽  
Railway Bridges ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
Protective Performance ◽  
The Impact

In Korea, to prepare for unexpected accidents caused by human errors and natural disasters that cannot be completely prevented, a protective wall (a type of side-structure) against derailed trains has been installed on high-speed railway bridges as one of the physical measures to mitigate the associated damage. However, taking the geometric aspects of a domestic railway bridge's super structure into consideration, such a protective wall is not appropriate, and the corresponding protective performance does not provide adequate security. Hence, a protective wall named Derailment Containment Provision (DCP) was newly developed and installed in the track gauge. In this study, to evaluate the impact resistance of the newly developed DCP, a drop weight experiment was conducted, and the impact behavior corresponding to a specific impact energy was analyzed.

Assessment of Dynamic Responses of Skin Simulant in a Drop Weight Penetration Test

2016 ◽  
Vol 715 ◽  
pp. 33-38
Author(s):  
Jonas A. Pramudita ◽  
Masashi Kato ◽  
Yuji Tanabe
Keyword(s):  
Penetration Depth ◽  
Assessment Method ◽  
Dynamic Responses ◽  
Curvature Radius ◽  
Penetration Test ◽  
Static Test ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
Test Result

Skin laceration injury caused by a penetration of small curvature edge frequently occurs in a domestic accident. An assessment method for this injury is necessary in order to develop a safer manufactured product. To assess the risk of skin laceration injury in a penetration accident, a skin simulant made from silicone rubber was proposed. However, mechanical responses of this skin simulant under dynamic penetration loading have not yet been investigated. In this study, a drop weight penetration test device was developed in order to simulate penetration accidents under impact velocities of over 1 m/s. The device was then used for investigating the dynamic responses of skin simulant against several blades with different tip curvature radii. Load, penetration depth, impulse and energy at rupture were then determined from the test results. Load and penetration depth at rupture increased with the increase of tip curvature radius of the blades. Furthermore, the drop weight test result showed larger response compared to the quasi-static test result which might be caused by the viscous effect and the polymer characteristics such as cross-linking of the skin simulant.

Instrumented drop-weight test results for normalised and tempered 9Cr1Mo steel

1996 ◽  
Vol 69 (3) ◽  
pp. 253-261 ◽  
Author(s):  
A. Moitra ◽  
P.R. Sreenivasan ◽  
S.K. Ray ◽  
S.L. Mannan
Keyword(s):  
Test Results ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test

Impact Testing of Concrete Using a Drop-Weight Impact Machine

2015 ◽  
Vol 1106 ◽  
pp. 225-228 ◽  
Author(s):  
Stanislav Rehacek ◽  
Petr Hunka ◽  
David Citek ◽  
Jiri Kolisko ◽  
Ivo Simunek
Keyword(s):  
Positive Impact ◽  
Impact Load ◽  
Impact Testing ◽  
Impact Loads ◽  
Test Machine ◽  
Impact Machine ◽  
Drop Weight ◽  
Weight Test ◽  
Load Tests ◽  
Drop Weight Test

Fibre-reinforced composite materials are becoming important in many areas of technological application. In addition to the static load, such structures may be stressed with short-term dynamic loads or even dynamic impact loads during their lifespan. Impact loading of structural components produces a complex process, where both the characteristics of the design itself and the material parameters influence the resultant behavior. It is clear that fibre reinforced concrete has a positive impact on increasing of the resistance to impact loads. Results of two different impact load tests carried out on drop-weight test machine are presented in this report.

Crucial Parameters of the Drop-Weight Test for IF Steels

2006 ◽  
pp. 107-115
Author(s):  
Angelika Spalek ◽  
Gerd Reisner ◽  
Ewald Werner ◽  
Andreas Pichler ◽  
Peter Stiaszny
Keyword(s):  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test

scholarly journals Mechanical Properties and Reaction Characteristics of Al-ZrH2-PTFE Composites under Quasi-Static Compression

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 421 ◽  
Author(s):  
Jun Zhang ◽  
Xiang Fang ◽  
Yuchun Li ◽  
Zhongshen Yu ◽  
Junyi Huang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Reaction Mechanism ◽  
High Speed ◽  
Calorific Value ◽  
Reaction Rates ◽  
Zirconium Hydride ◽  
Reaction Products ◽  
Static Compression ◽  
Reaction Characteristics ◽  
Quasi Static Compression

To analyze the mechanical properties and reaction characteristics of Al-ZrH2-PTFE (aluminum-zirconium hydride-polytetrafluoroethylene) composites under quasi-static compression, five types of specimens with different ZrH2 contents (0%, 5%, 10%, 20% and 30%) were prepared by molding-vacuum sintering. The true stress-strain curves and reaction rates of the different specimens were measured using quasi-static compression. The specific reaction processes were recorded by a high-speed camera. The corresponding reaction products were characterized by the XRD phase analysis, the calorific value was tested by a Calorimeter, and the reaction mechanism was analyzed. According to the results, the strength of the composites increased first and then decreased with the increase in the content of ZrH2. It reached a maximum of 101.01 MPa at 5%. Violent reaction occurred, and special flames were observed during the reaction of the specimens with 5% ZrH2. With the increase in the content of ZrH2, the chemical reaction was hard to induce due to the reduction in strength and toughness of composites. The reaction mechanism of Al/ZrH2/PTFE reveals that high temperatures at crack tip induced the reaction of Al and PTFE. Subsequently, ZrH2 decomposed to release hydrogen and generate ZrC. Calorimetric experiment shows that the calorific value of Al/ZrH2/PTFE with 20% ZrH2 is higher than that of Al/PTFE. The findings verify the potential of ZrH2 as an energetic additive for the enhancement of strength and release of the energy of the composites.

Effect of specimen size and ball size on breakage throughput in the drop-weight test

2018 ◽  
Vol 233 (2) ◽  
pp. 202-210 ◽  
Author(s):  
Mehdi Akhondizadeh ◽  
Masoud Rezaeizadeh
Keyword(s):  
Impact Energy ◽  
Specimen Size ◽  
Test Machine ◽  
Ball Size ◽  
Drop Weight ◽  
Weight Test ◽  
Drop Weight Test ◽  
Steel Balls ◽  
The Impact ◽  
Specific Impact

Effects of specimen size and ball size on the breakage throughput under the impact loading are investigated using a drop-weight test machine. Samples are square-shaped building stones ranging 20–60 mm in width and 22–256 g in mass. They include granite, marble, and two types of travertine with the thickness of 15 mm. The impact energies, up to 160 J, are achieved by falling balls in a drop-weight test machine. Several steel balls with the diameter of 60, 84, 96, and 120 mm have been used as an impactor. The ball size is a parameter whose effect on the breakage throughput is investigated here. Results show that the larger specimens have better breakage than the smaller ones at the same specific impact energy. It is also indicated that, at constant specific impact energy, the smaller balls behave more efficiently than the larger balls.

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