scholarly journals SELECTED TECHNICAL AND LEGAL ASPECTS OF THE PNEUMATIC LAUNCHER OPERATION FOR HOPKINSON MEASURING BARS SET

2020 ◽  
Author(s):  
Kamil Sobczyk ◽  
Leopold Kruszka ◽  
Ryszard Chmielewski ◽  
Ryszard Rekucki
Keyword(s):  
Mechanical Test ◽  
Dynamic Properties ◽  
Construction Materials ◽  
Legal Aspects ◽  
Test Stand ◽  
Physical Experiments ◽  
University Of Technology ◽  
Split Hopkinson ◽  
Material Sample ◽  
The Military

The paper presents selected technical and legal areas of the exploitation of a pneumatic launcher as an essential part of the mechanical test stand of the split Hopkinson bar for testing the dynamic properties of construction materials. The process of impact loading of the tested material sample is carried out by means of a loading bar-projectile fired from this launcher. The concept of the first stage of the modernization of the pneumatic launcher used at the Institute of Civil Engineering of the Military University of Technology (MUT) for over 20 years was discussed in order to facilitate the performance of physical experiments. The formal and legal requirements for the design, construction and usage of a test stand with a pneumatic launcher in a laboratory room are presented.

scholarly journals KONCEPCJA BADAŃ EKSPERYMENTALNYCH ZACHOWANIA SIĘ MATERIAŁU OBSYPKI PIASKOWEJ UKRYĆ OCHRONNYCH DLA LUDNOŚCI CYWILNEJ

2020 ◽  
Author(s):  
Kamil Sobczyk ◽  
Ryszard Chmielewski ◽  
Leopold Kruszka
Keyword(s):  
Split Hopkinson Pressure Bar ◽  
Civil Defense ◽  
Hopkinson Pressure Bar ◽  
Legal Provisions ◽  
University Of Technology ◽  
Loose Soil ◽  
Split Hopkinson ◽  
Original Laboratory ◽  
Pressure Bar ◽  
The Military

The article proposes the concept of experimental dynamic tests of aggregate behavior - sand used as a material for covering temporary protective shelters for the population and civil defense. These shelters are part of the construction shielding infrastructure useful in crisis situations. Laboratory tests of loose soil, including sand, with impact loads, are based on the Split Hopkinson Pressure Bar using a clamp. The work describes both this experimental method and the original laboratory stand for impact tests based on a pneumatic launcher with a projectile - bar. This position was built at the Institute of Civil Engineering of the Military University of Technology taking into account the requirements of generally applicable legal provisions. Examples of preliminary experimental research on the behavior of selected aggregate - dry sand under dynamic load - are presented.

scholarly journals Performance characteristics of Hopkinson’s set-up pneumatic launcher

2021 ◽  
Vol 61 (4) ◽  
pp. 552-561
Author(s):  
Kamil Sobczyk ◽  
Leopold Kruszka ◽  
Ryszard Chmielewski ◽  
Ryszard Rekucki
Keyword(s):  
Construction Materials ◽  
Small Diameter ◽  
Dynamic Strength ◽  
Cylindrical Sample ◽  
Performance Characteristics ◽  
Empirical Formulas ◽  
Experimental Calibration ◽  
Split Hopkinson ◽  
Set Up ◽  
The Military

The paper presents a performance characteristics of a pneumatic launcher, which is an important element of the split Hopkinson bar set-up (SHPB) at the Department of Military Engineering and Infrastructure (the Military University of Technology in Warsaw) for the purpose of dynamic strength tests of construction materials. The process of experimental calibration of the launcher for selected loading bar-projectiles is shown. Two types of compression during direct impact tests were also used simultaneously to investigate the behaviour of metallic samples with the use of this launcher as well as the Hopkinson measuring bar: the first — a short cylindrical sample, including a miniature (small diameter) sample, and the second — a long cylindrical sample (Taylor test). The relationships describing the stress and strain state as a function of strain rate for the first type of the experiment and engineering empirical formulas for the second type of the research were given.

scholarly journals Study on the dynamic properties of AM-SLM AlSi10Mg alloy using the Split Hopkinson Pressure Bar (SHPB) technique

2018 ◽  
Vol 183 ◽  
pp. 04005 ◽  
Author(s):  
Bar Nurel ◽  
Moshe Nahmany ◽  
Adin Stern ◽  
Nahum Frage ◽  
Oren Sadot
Keyword(s):  
Strain Rate ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Rate Sensitivity ◽  
Strain Rate Range ◽  
Strain Rates ◽  
Hopkinson Pressure Bar ◽  
Static Mechanical ◽  
Split Hopkinson ◽  
Pressure Bar

Additive manufacturing by Selective Laser Melting of metals is attracting substantial attention, due to its advantages, such as short-time production of customized structures. This technique is useful for building complex components using a metallic pre-alloyed powder. One of the most used materials in AMSLM is AlSi10Mg powder. Additively manufactured AlSi10Mg may be used as a structural material and it static mechanical properties were widely investigated. Properties in the strain rates of 5×102–1.6×103 s-1 and at higher strain rates of 5×103 –105 s-1 have been also reported. The aim of this study is investigation of dynamic properties in the 7×102–8×103 s-1 strain rate range, using the split Hopkinson pressure bar technique. It was found that the dynamic properties at strain-rates of 1×103–3×103 s-1 depend on a build direction and affected by heat treatment. At higher and lower strain-rates the effect of build direction is limited. The anisotropic nature of the material was determined by the ellipticity of samples after the SHPB test. No strain rate sensitivity was observed.

Quasi-Static and High Strain Rate Uniaxial Compressive Response of Recycled Polycarbonate from Industrial Waste

2020 ◽  
Vol 1012 ◽  
pp. 89-93
Author(s):  
Anderson Oliveira da Silva ◽  
Ricardo Pondé Weber ◽  
Sergio Neves Monteiro
Keyword(s):  
Industrial Waste ◽  
Split Hopkinson Pressure Bar ◽  
Dynamic Properties ◽  
Hopkinson Pressure Bar ◽  
Mechanical Recycling ◽  
Static Compression ◽  
Compressive Response ◽  
Split Hopkinson ◽  
Pressure Bar ◽  
Quasi Static Compression

This work evaluates the mechanical and dynamic behavior of recycled polycarbonate (rPC) from industrial waste. This study aims to verify whether the recycled process adopted for polycarbonate promotes both mechanical and dynamic properties values under compressive stress, similar to those found for virgin polycarbonate. The mechanical recycling of the rPC was carried out using the thermoforming technique in a thermal press. Two tests were carried out to evaluate the dynamic response of rPC. The quasi-static compression test was performed on a universal machine. The dynamic in a split Hopkinson pressure bar was performed with three different strain rates. The results showed that the mechanical and primary recycling adopted in this work promoted values of yield stress in compression (77 MPa) and dynamic (up to 118 MPa), close to or superior to those reported so far in the literature.

Influence of the Supplementary Cementitious Materials on the Dynamic Properties of Concrete

2014 ◽  
Vol 660 ◽  
pp. 162-167
Author(s):  
Elbachir Elbahi ◽  
Sidi Mohammed El Amine Boukli Hacene
Keyword(s):  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Construction Materials ◽  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Natural Pozzolan ◽  
Frequency Method ◽  
Concrete Mixtures ◽  
And Control ◽  
Non Destructive

The resonance frequency method is one of many non-destructive tests which allow us to evaluate construction materials. It was used to determine the dynamic properties of concrete, required in structures design and control, also considered as the key elements for materials dynamic. In this study, we chose a non-destructive approach to quantify-in laboratory-, the influence of adding “crushed limestone” and “natural pozzolan” on local concrete’s dynamic characteristics. However, several concrete mixtures have been prepared with limestone aggregates. The experimental used plan, allowed us to determine the dynamic modulus of elasticity, the dynamic modulus of rigidity of different formulated concretes.

Study on carbon dioxide thermodynamic behavior for the purpose of shale rock fracturing

2013 ◽  
Vol 61 (3) ◽  
pp. 605-612 ◽  
Author(s):  
T. Niezgoda ◽  
D. Miedzińska ◽  
E. Małek ◽  
P. Kędzierski ◽  
G. Sławiński
Keyword(s):  
Carbon Dioxide ◽  
Closed Volume ◽  
Rock Fracturing ◽  
Thermodynamic Behavior ◽  
Shale Rock ◽  
University Of Technology ◽  
Liquid Co2 ◽  
Applied Computer Science ◽  
Efficient Extraction ◽  
The Military

Abstract The possibility of using CO2 to fracturing a shale rock has been presented in the paper. The described innovative method which allows for the efficient extraction of shale gas and carbon dioxide storage in a shale rock was developed in Department of Mechanics and Applied Computer Science at the Military University of Technology, Warsaw, Poland. Firstly, the method was verified on the base of analytical and experimental research. In the next stage of the method verification carbon dioxide thermodynamic behavior was studied. The growth in pressure of drop of CO2 heated in a closed volume was numerically tested. The research confirmed the efficiency of the use of carbon dioxide as a medium for fracturing of rocks. The usage of liquid CO2 can be alternative for hydraulic fracturing and is safe for the environment.

Experimental Analysis of Visco-Plastic Properties of the Aluminium and Tungsten Alloys by Means of Hopkinson Bars Technique

2014 ◽  
Vol 566 ◽  
pp. 110-115 ◽  
Author(s):  
Leopold Kruszka ◽  
Mariusz Magier ◽  
Mariusz Zielenkiewicz
Keyword(s):  
Aluminium Alloy ◽  
Testing Machine ◽  
Construction Materials ◽  
Constitutive Models ◽  
Tungsten Alloy ◽  
Strain Rates ◽  
Dynamic Tests ◽  
Plastic Properties ◽  
Split Hopkinson ◽  
And Tungsten

The main aim of studies on dynamic behaviour of construction materials at high strain rates is to determine the variation of mechanical properties (strength, plasticity) as a function of the strain rate and temperature. On the basis of results of dynamic tests on the properties of constructional materials the constitutive models are formulated to create numerical codes applied to solve constructional problems with computer simulation methods. In the case of military applications connected with the phenomena of gunshot and terminal ballistics it's particularly important to develop a model of strength and armour penetration with KE projectile founded on reliable results of dynamic experiments and constituting the base for further analyses and optimization of projectile designs in order to achieve required penetration depth. Static and dynamic results of strength investigations of the EN AW-7012 aluminium alloy (sabot) and tungsten alloy (penetrator) are discussed in this paper. Static testing was carried out with the INSTRON testing machine. Dynamic tests have been conducted using the split Hopkinson pressure bars technique at strain rates up to 1,2·104 s-1 (for aluminium alloy) and 6·103 s-1 (for tungsten alloy).

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