scholarly journals Analisis Numerik Penyerapan Energi pada Sabot untuk Pengujian Bird Strike

2020 ◽  
Vol 5 (2) ◽  
Author(s):  
Riskha Agustianingsih

abstrak - Pengujian Bird Strike dilakukan menggunakan alat SHPB (Split Hopkinson Pressure Bar) yang menembakkan sabot (wadah burung). Pada ujung alat SHPB, sabot akan dihentikan oleh stopper sehingga burung akan terlepas dan meluncur dengan bebas hingga mengalami tumbukan dengan komponen uji. Sabot harus memaksimalkan kecepatan burung ketika keluar (terlepas dari sabot). Berdasarkan persamaan impuls dan momentum, hal ini dapat diperoleh dengan meminimalkan waktu tumbukan sehingga gaya impulsnya akan meningkat. Tujuan penelitian ini adalah mengetahui waktu tumbukan, pola grafik Energy Absorption (EA), Peak Crushing Force (PCF), dan Mean Crushing Force (MCF). Dari parameter tersebut, maka diperoleh sabot yang diinginkan berdasarkan waktu tumbukan tersingkat, PCF dan MCF tertinggi, serta EA terendah. Simulasi dilakukan menggunakan perangkat lunak elemen hingga (Abaqus CAE) berdasarkan variasi material (AA6061-T6, S355, dan AISI 1340) sabot. Berdasarkan hasil dan pembahasan, diperoleh bahwa waktu tumbukan paling singkat dimiliki variasi material AISI 1340 dengan nilai 0.00071 s. EA terendah untuk variasi material dimiliki oleh AISI 1340, yaitu sebesar 2.51 kJ. PCF tertinggi untuk variasi material dimiliki oleh material AISI 1340, yaitu 466 kN. Ditentukan bahwa berdasarkan nilai waktu (t) paling singkat, PCF, MCF paling tinggi, dan EA paling rendah, maka diperoleh material AISI 1340 sebagai material yang diinginkan karena paling berpengaruh terhadap peningkatan kecepatan burung setelah keluar dari sabot.

2016 ◽  
Vol 51 (1) ◽  
pp. 81-94 ◽  
Author(s):  
Khubab Shaker ◽  
Abdul Jabbar ◽  
Mehmet Karahan ◽  
Nevin Karahan ◽  
Yasir Nawab

In this paper, high strain rate compression properties of aramid and ultrahigh molecular weight polyethylene composites in the out-of-plane direction are tested at room temperature on a Split Hopkinson Pressure Bar apparatus. Tests were conducted on composites reinforced with woven or Uni-Directional (UD) fabrics made from aramid or ultrahigh molecular weight polyethylene as well as on composites reinforced with hybrid reinforcement. The strain rate is varied in the tests by changing the projectile shooting pressure. Four different pressures 2, 4, 6 and 8 bar were selected to change the strain rate. Stress–strain and energy absorption behaviour of eight type of samples were noted. Hybrid samples showed better performance in the energy absorption compared with other samples.


2015 ◽  
Vol 1124 ◽  
pp. 243-248
Author(s):  
Ondřej Koutný ◽  
Josef Krátký ◽  
Miloslav Popovič ◽  
Martina Drdlová

This article presents a new direct testing method and device for evaluation of response of blast-absorption materials against direct blast wave and its ability to absorb energy generated during this type of loading. This is a second step of characterization of blast energy absorption materials which take place after standard and most common characterization using Split-Hopkinson pressure bar. The principle of the method is an assessment of longitudinal stress process in standard rod after the explosion of testing blast charge. Stress amplitude reduction in standard rod caused due to energy-absorption of sample material will directly lead to absorption capability of tested sample material.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 9444-9461
Author(s):  
Damian Stoddard ◽  
Suman Babu Ukyam ◽  
Brent Tisserat ◽  
Ivy Turner ◽  
Rowan Baird ◽  
...  

Novel bio-based composite wood panels (CWPs) that consisted of distiller’s dried grains and solubles (DDGS) flour adhesive bound to a wood filler/reinforcement were subjected to high strain-rate compression loading, and their behavior was investigated. Specimens of DDGS-Paulownia wood (PW) or DDGS-pinewood (Pine) composites made using DDGS with fractions of 10%, 15%, 25%, and 50% were tested at high strain-rates using a modified compression Split Hopkinson Pressure Bar (SHPB). Both DDGS-PW and DDGS-Pine composites displayed strain-rate sensitivity, and DDGS-PW had a 25% fraction, which showed the highest ultimate compressive strength of 655 MPa at approximately 1600/s. The 90%-PW had the highest specific energy of 19.24 kJ/kg at approximately 1600/s when loaded via dynamic compression. The CWPs constructed of DDGS-PW had higher strength and energy absorption than DDGS-Pine with the exception of the 50% DDGS composites.


2021 ◽  
Vol 11 (21) ◽  
pp. 9882
Author(s):  
Jiangping Chen ◽  
Weijun Tao ◽  
Shumeng Pang

In this study, a total of 30 3D re-entrant honeycomb specimens made of polyamide were fabricated with various configurations by using the additive manufacturing (AM) technique. Split Hopkinson Pressure Bar (SHPB) tests were conducted on the RH specimens at different impact velocities. The incident, reflected and transmitted waveforms can well explain the wave propagation and energy absorption characteristics of the specimens, which can help us to understand and analyse the process of impact loading. The stress–strain curves, energy absorption ability and failure modes of SHPB tests with different impact velocities and quasi-static compression tests were analysed and compared, and it was found that the flow stress and energy absorption ability of the specimens subjected to impact load were much improved. Among the tested specimens, specimen C2, with a smaller re-entrant angle θ, displayed the best energy absorption ability, which was 1.701 J/cm3 at the impact velocity of 22 m/s and was 5.1 times that in the quasi-static test. Specimen C5 had the longest horizontal length of the diagonal bar L0, and its energy absorption was 1.222 J/cm3 at the impact velocity of 22 m/s and was 15.7 times that in the quasi-static test, reflecting the superiority of a structurally stable specimen in energy absorption under impact loading. The test results can provide a reference for the optimization of the design of the same or similar structures.


2013 ◽  
Vol 20 (4) ◽  
pp. 555-564 ◽  
Author(s):  
Wojciech Moćko

Abstract The paper presents the results of the analysis of the striker shape impact on the shape of the mechanical elastic wave generated in the Hopkinson bar. The influence of the tensometer amplifier bandwidth on the stress-strain characteristics obtained in this method was analyzed too. For the purposes of analyzing under the computing environment ABAQUS / Explicit the test bench model was created, and then the analysis of the process of dynamic deformation of the specimen with specific mechanical parameters was carried out. Based on those tests, it was found that the geometry of the end of the striker has an effect on the form of the loading wave and the spectral width of the signal of that wave. Reduction of the striker end diameter reduces unwanted oscillations, however, adversely affects the time of strain rate stabilization. It was determined for the assumed test bench configuration that a tensometric measurement system with a bandwidth equal to 50 kHz is sufficient


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