Penetration depth of RC panels subjected to the impact of aircraft engine missiles

2018 ◽  
Vol 335 ◽  
pp. 44-53 ◽  
Author(s):  
T. Zhang ◽  
H. Wu ◽  
T. Huang ◽  
J.H. Sheng ◽  
Q. Fang ◽  
...  
Author(s):  
Miloš Pjević ◽  
Ljubodrag Tanović ◽  
Goran Mladenović ◽  
Biljana Marković

The paper presents experimental results of microcutting brittle materials (granite). The analysis was conceived on the observed interaction between the workpiece and two tools of different shapes. Experiment was based on scratching the workpiece surface with diamond tools. Applied tools had tip radius R0.2 and R0.15 mm. The experiment determined the changes in the value of perpendicular and tangential components of the cutting force based on the geometric properties of tools, as well as the changes of the specific energy of microcutting granite (Jošanica and Bukovik types). The experiment has shown that reduction of tool radius causes reduction of the cutting force intensity and specific cutting energy. Because of its physical/mechanical properties, more energy is required for micromachining granite “Jošanica” than “Bukovik.” Based on the topography of the surface, the value of critical tool penetration depth was established, after which the brittle fracture is no longer present. For granite “Jošanica” values of critical penetration depth are 6 and 5 μm when micromachining with tools R0.2 and R0.15 mm, while for Bukovik those values are 6.5 and 5.5 μm. The paper should form the basis for understanding the phenomena which occur during microcutting brittle materials.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ilkay Orhan

Purpose The purpose of this study is to present the pollutant gas produced by hydrocarbons (HC), carbon monoxide (CO) and nitrogen oxides (NOx) and the quantity of fuel burned from commercial aircraft at Ordu-Giresun International Airport, Turkey during the landing and take-off (LTO) cycles in 2017. Design/methodology/approach The flight data recorded by the General Directorate of State Airports Authority and the aircraft engine emission data from International Civil Aviation Organization (ICAO) Engine Exhaust Emission Databank were used for calculation. The aircraft and engine types used by the airlines for flight at Ordu-Giresun International Airport were determined. To evaluate the effect of taxi time on emission amounts, analysis and evaluations were made by taking different taxi times into consideration. Findings As a result of the emission analysis, the amount of fuel consumed by the aircraft were calculated as 6,551.52 t/y, and the emission amounts for CO, HC and NOx were estimated as 66.81, 4.20 and 79.97 t/y, respectively. Practical implications This study is aimed to reveal the effect and contribution of taxi time on the emitted emission at the airport during the LTO phase of the aircraft. Originality/value This study helps aviation authorities explain the importance of developing procedures that ensure the delivery of aircraft to flights in minimum time by raising awareness of the impact of taxi time on emitted emissions, and contributes to the determination of an aircraft emission inventory at Ordu-Giresun International Airport.


2018 ◽  
Vol 861 ◽  
Author(s):  
Ishan Sharma

We present a simple hydrodynamical model for the high-speed impact of slender bodies into frictional geomaterials such as soils and clays. We model these materials as non-smooth, complex fluids. Our model predicts the evolution of the impactor’s speed and the final penetration depth given the initial impact speed, and the material and geometric parameters of the impactor and the impacted material. As an application, we investigate the impact of deep-penetrating anchors into seabeds. Our theoretical predictions are found to match field and laboratory data very well.


Author(s):  
Kenro Obuchi ◽  
Fumiaki Watanabe ◽  
Hiroshi Kuroki ◽  
Hiroyuki Yagi ◽  
Kazuyoshi Arai

Ceramic matrix composites (CMCs) have lower density and a higher service temperature limit than nickel based alloys which have been used for turbine components of aircraft engines. These properties of CMCs have the potential to reduce the weight of turbine components and improve turbine thermal efficiency with a higher turbine inlet temperature (TIT). One of the technical issues of the CMC turbine vane is a relatively lower impact resistance than nickel based alloy turbine vanes. There are various previous works about impact resistance of CMCs, but there is little work that assumed actual engine conditions. The objective of this work was to verify the resistance of SiC/SiC CMC turbine vane to the impact phenomena that occur in the actual aircraft engine. The field damage survey was conducted on actual metal turbine vanes of commercial engines overhauled in IHI. The survey made it clear that the typical damage was less-than-0.127-mm-dent at the leading edge. In addition, the dropped weight impact test using the actual turbine airfoil which is made from a nickel based alloy was conducted at ambient temperature. The amount of energy required to make the dent of a certain size that was observed in actual metal turbine vanes was estimated. Then, the dropped weight impact test using the CMC test piece with a leading edge shape was conducted at the impact energy estimated by the metal turbine airfoil. The results showed that the failure mode of the CMC test piece was local damage with dents of a certain size and not a catastrophic failure mode. From this work, the damage to be assumed on CMC vane in actual aircraft engines was identified. As a future task, the effect of the damage to the fatigue capability of CMC turbine vanes needs to be investigated.


2014 ◽  
Vol 59 (4) ◽  
pp. 1559-1563 ◽  
Author(s):  
M. Ciesla ◽  
M. Manka ◽  
P. Gradon ◽  
F. Binczyk

Abstract The study assesses the impact of surface and bulk modification and filtration during pouring on a durability under accelerated creep conditions of casts made of IN-713C and MAR-247 nickel superalloys scrap used for manufacturing of aircraft engine parts. The impact of solutionizing (1185°C/2 h) with subsequent ageing (870°C/20 h) on the creep resistance of a casting made from MAR-247 coarse-grained superalloy was also examined. Morphological structure parameters were determined with the use of Met-Ilo software. Macrostructure analysis of casts showed very significant impact of surface modification treatment. Creep test results clearly showed that coarse grained samples of IN-713C and MAR-247 superalloys have higher creep resistance. Moreover alloy MAR-247 had higher creep durability after heat treatment compared to as-cast state.


Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 487 ◽  
Author(s):  
Gabriela Rutkowska ◽  
Piotr Wichowski ◽  
Małgorzata Franus ◽  
Michał Mendryk ◽  
Joanna Fronczyk

This article focuses on the impact of fly ash from the combustion of municipal sewage sludge (FAMSS) as a cement additive in the amounts of 5%, 10%, 15%, 20% and 25% (by mass) on selected concrete properties. In the course of the experimental work, water penetration depth and compressive strength measurements were made at various periods of curing (from 2 to 365 days). In addition, the potential impact of FAMSS on the natural environment was examined by determining the leachability of heavy metals. FAMSS-modified concretes showed small values of water penetration depth (lower than 50 mm), as well as good compressive strength (reaching minimum class C30/37 after 130 days of maturing)—similar to the compressive strength obtained for conventional concrete. In addition, the partial replacement of cement with FAMSS has environmental benefits, expressed as a reduction in CO2 emissions. In addition, study has shown that compliance with environmental requirements is associated with heavy metal leaching.


2018 ◽  
Vol 41 (4) ◽  
pp. 990-1001
Author(s):  
Song Ma ◽  
Jianguo Tan ◽  
Xiankai Li ◽  
Jiang Hao

This paper establishes a novel mathematical model for computing the plume flow field of a carrier-based aircraft engine. Its objective is to study the impact of jet exhaust gases with high temperature, high speed and high pressure on the jet blast deflector. The working condition of the nozzle of a fully powered on engine is first determined. The flow field of the exhaust jet is then numerically simulated at different deflection angle using the three-dimensional Reynolds averaged Navier–Stokes equations and the standard [Formula: see text]-[Formula: see text] turbulence method. Moreover, infra-red temperature tests are further carried out to test the temperature field when the jet blast deflector is at the [Formula: see text] deflection angle. The comparison between the simulation results and the experimental results show that the proposed computation model can perfectly describe the system. There is only 8–10% variation between them. A good verification is achieved. Moreover, the experimental results show that the jet blast deflector plays an outstanding role in driving the high-temperature exhaust gases. It is found that [Formula: see text] may be the best deflection angle to protect the deck and the surrounding equipment effectively. These data results provide a valuable basis for the design and layout optimization of the jet blast deflector and deck.


2020 ◽  
Vol 10 (2) ◽  
pp. 522
Author(s):  
Xiaojia Zhao ◽  
Wim J.C. Verhagen ◽  
Richard Curran

The present study proposes an economic indicator to support the evaluation of aircraft End of Life (EoL) strategies in view of the increasing demand with regards to aircraft decommissioning. This indicator can be used to evaluate an economic performance and to facilitate the trade-off studies among different strategies. First, Disposal and Recycle (D&R) scenarios related to stakeholders are investigated to identify the core concepts for the economic evaluation. Next, we extracted the aircraft D&R process from various real-life practices. In order to obtain the economic measure for the engineering process, a method of estimating the D&R cost and values are developed by integrating product, process and cost properties. This analysis is demonstrated on an averaged data set and two EoL aircraft cases. In addition, sensitivity analysis is performed to evaluate the impact of the D&R cost, residual value, and salvage value. Results show that the disassembly and dismantling of an aircraft engine possesses relatively more economic gains than that for the aircraft. The main factors influencing the proposed D&R economic indicator are the salvage value and D&R cost for economically efficient D&R cases. In addition, delaying the disposal and recycle process for EoL aircraft can lead to economically unfavorable solutions. The economic indicator combined with the evaluation methods is widely applicable for evaluations of engineering products EoL solutions, and implies a significant contribution of this research to decision making for such complex systems in terms sustainable policy.


2015 ◽  
Vol 778 ◽  
pp. 205-211
Author(s):  
Li He ◽  
Jin Yuan Tang

Solving gear meshing impact force problems by using ADAMS software is studied.A pair of tooth meshing model is established based on UG, modal neutral file is generated by using ANSYS software, calculating gear meshing impact after Importing ADAMS. The relationship between the impact velocity and the impact force by taking reasonable key parameter about penetration depth in ADAMS simulation.A new approach for studying gear meshing impact is proposed here, and the simulation results show that ADAMS software is a very useful tool for solving gear corner contact shock problems outside the normal path of action line.


2017 ◽  
Vol 121 (1246) ◽  
pp. 1808-1832 ◽  
Author(s):  
E.O. Smith ◽  
A.J. Neely ◽  
H. Palfrey-Sneddon

ABSTRACTWhen a gas turbine engine is shut down it will develop a circumferential thermal gradient vertically across the compressor due to hot air rising from the cooling metal components and pooling at the top. As the hot compressor rotor drum and casing cool and contract in the presence of this thermal gradient, they do so non-uniformly and therefore will bend slightly, in a phenomenon known as rotor bow. Starting an engine under bowed conditions can result in damage, representing a risk to both airworthiness and operational capability. This study consolidates some preliminary findings by the authors relating to the drivers for rotor bow, such as engine geometry, aircraft-engine integration and rotor temperature on shutdown. The commercial and military operational considerations associated with rotor bow are also discussed, including limitations which may result from a bowed rotor; the influence of operations including the final flight and descent profiles, taxi procedures and rapid turnaround requirements; as well as some practical solutions which may be implemented to reduce the impact of rotor bow.


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