scholarly journals Dynamic impact testing of cellular solids and lattice structures: Application of two-sided direct impact Hopkinson bar

2021 ◽  
Vol 148 ◽  
pp. 103767
Author(s):  
Tomáš Fíla ◽  
Petr Koudelka ◽  
Jan Falta ◽  
Petr Zlámal ◽  
Václav Rada ◽  
...  
Keyword(s):  
Hopkinson Bar ◽  
Impact Testing ◽  
Lattice Structures ◽  
Cellular Solids ◽  
Direct Impact ◽  
Dynamic Impact

Study on Impact Protection Properties of Titanium Alloy Using Modified SHPB

2013 ◽  
Vol 302 ◽  
pp. 14-19 ◽  
Author(s):  
Jie Liu ◽  
Jin Xu Liu ◽  
Hong Sheng Ding ◽  
Shu Kui Li ◽  
Yu Meng Luo
Keyword(s):  
Impact Velocity ◽  
Loading Condition ◽  
Hopkinson Bar ◽  
Impact Testing ◽  
Direct Impact ◽  
Protective Properties ◽  
Impact Protection ◽  
Protective Performance ◽  
The Impact ◽  
Modified Hopkinson Bar

In order to evaluate the impact protection capacity of armor material quantitatively, direct impact testing loaded by modified Hopkinson bar was used to simulate the impaction between penetrator and armor. Protection coefficient k was defined to describe the protective performance. Using the direct impact testing, Ti-6Al-4V specimens with different microstructure and thickness were tested. Results show that k decreases with increased impact velocity and increases with increased thickness of specimen. Under a given loading condition, binary microstructure exhibits the highest k, indicating the best protective performance. Moreover, its k shows the most sensitivity to thickness (mt) and the least sensitivity to impact energy (me), which means that its protective performance can be improved most efficiently by increasing its thickness and it will exhibit good protective performance in a wider impact velocity range. This new method can evaluate the impact protective properties of armor materials efficiently, which may have a broad application prospect.

Dynamic Impact Testing of Polyurethane Energy Absorbing (EA) Foams

1994 ◽  
Author(s):  
David F. Sounik ◽  
Dennis W. McCullough ◽  
John L. Clemons ◽  
John L. Liddle
Keyword(s):  
Impact Testing ◽  
Dynamic Impact ◽  
Energy Absorbing

scholarly journals Impact performance of aluminium foams in a direct impact Hopkinson bar

2018 ◽  
Author(s):  
T. Cowie ◽  
C. W. A. Gurnham ◽  
C. H. Braithwaite ◽  
L. Lea
Keyword(s):  
Hopkinson Bar ◽  
Direct Impact ◽  
Impact Performance

scholarly journals Comparison of Lifetime of the PVD Coatings in Laboratory Dynamic Impact Test and Industrial Fine Blanking Process

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2154
Author(s):  
Josef Daniel ◽  
Radek Žemlička ◽  
Jan Grossman ◽  
Andreas Lümkemann ◽  
Peter Tapp ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Testing ◽  
Pvd Coatings ◽  
Dynamic Impact ◽  
Repeated Impact ◽  
Suitable Alternative ◽  
Fine Blanking ◽  
Blanking Process

Protective hard PVD coatings are used to improve the endurance of the tools exposed to repeated impact load, e.g., fine blanking punches. During the fine blanking process, a coated punch repeatedly impacts sheet metal. Thus, the coating which protects the punch surface is exposed to the dynamic impact load. On the other hand, the laboratory method of dynamic impact testing is well known and used for the development and optimization of protective coatings. This paper is focused on the comparison of tool life and lifetime of the industrial prepared PVD coatings exposed to repeated dynamic impact load in the industrial fine blanking process and the laboratory dynamic impact testing. Three different types of protective coatings were tested and the results were discussed. It was shown that the lifetime of coated specimens in both the fine blanking and the dynamic impact processes was influenced by similar mechanical properties of the protective coatings. The qualitative comparison shows that the lifetime obtained by the dynamic impact test was the same as the lifetime obtained by the industrial fine blanking process. The laboratory impact test appears to be a suitable alternative for the optimisation and development of protective PVD coatings for punches used in the industrial fine blanking process.

scholarly journals A tool for the evaluation of human lower arm injury: approach, experimental validation and application to safe robotics

Robotica ◽  
2015 ◽  
Vol 34 (11) ◽  
pp. 2499-2515 ◽  
Author(s):  
B. Povse ◽  
S. Haddadin ◽  
R. Belder ◽  
D. Koritnik ◽  
T. Bajd
Keyword(s):  
Mathematical Model ◽  
Experimental Validation ◽  
Human Impacts ◽  
Industrial Robot ◽  
Impact Testing ◽  
Impact Response ◽  
Dynamic Impact ◽  
Good Consistency ◽  
Impact Experiments ◽  
Human Injury

SUMMARYThis paper treats the systematic injury analysis of lower arm robot–human impacts. For this purpose, a passive mechanical lower arm (PMLA) was developed that mimics the human impact response and is suitable for systematic impact testing and prediction of mild contusions and lacerations. A mathematical model of the passive human lower arm is adopted to the control of the PMLA. Its biofidelity is verified by a number of comparative impact experiments with the PMLA and a human volunteer. The respective dynamic impact responses show very good consistency and support the fact that the developed device may serve as a human substitute in safety analysis for the described conditions. The collision tests were performed with two different robots: the DLR Lightweight Robot III (LWR-III) and the EPSON PS3L industrial robot. The data acquired in the PMLA impact experiments were used to encapsulate the results in a robot independent safety curve, taking into account robot's reflected inertia, velocity and impact geometry. Safety curves define the velocity boundaries on robot motions based on the instantaneous manipulator dynamics and possible human injury due to unforeseen impacts.

A New Experimental Technique to Characterize the Fiber Crush and Fiber Shear Behavior of Composites at Quasi-Static and High Rates of Strain

2006 ◽  
Author(s):  
Bazle A. Gama ◽  
John W. Gillespie
Keyword(s):  
Shear Test ◽  
Material Model ◽  
Hopkinson Bar ◽  
Test Method ◽  
Experimental Methodology ◽  
Direct Impact ◽  
Damage Behavior ◽  
Material Parameters ◽  
Test Methodology ◽  
Crush Strength

A new experimental method is developed to determine the fiber crush strength (SFC) and fiber shear strength (SFS) of composite materials following a punch shear test methodology. The material parameters SFC and SFS are used to model the damage behavior of thick-section composites as described in the LS-Dyna material model MAT_COMPOSITE_DMG_MSC, aka MAT162. The quasi-static experimental methodology is further extended to investigate the rate effect on SFS using a Hopkinson bar direct impact punch shear test method.

scholarly journals DYNAMIC IMPACT WEAR AND IMPACT RESISTANCE OF W-B-C COATINGS

2020 ◽  
Vol 27 ◽  
pp. 37-41
Author(s):  
Josef Daniel ◽  
Jan Grossman ◽  
Vilma Buršíková ◽  
Lukáš Zábranský ◽  
Pavel Souček ◽  
...  
Keyword(s):  
Impact Test ◽  
Impact Load ◽  
Protective Coatings ◽  
Impact Resistance ◽  
Impact Testing ◽  
The Novel ◽  
Test Results ◽  
Dynamic Impact ◽  
Impact Deformation ◽  
The Impact

Coated components used in industry are often exposed to repetitive dynamic impact load. The dynamic impact test is a suitable method for the study of thin protective coatings under such conditions. Aim of this paper is to describe the method of dynamic impact testing and the novel concepts of evaluation of the impact test results, such as the impact resistance and the impact deformation rate. All of the presented results were obtained by testing two W-B-C coatings with different C/W ratio. Different impact test results are discussed with respect to the coatings microstructure, the chemical and phase composition, and the mechanical properties. It is shown that coating adhesion to the HSS substrate played a crucial role in the coatings’ impact lifetime.

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