Numerical Investigation of Toggle Assembly of Landing Gears in Aircraft: Technical note

2019 ◽  
Vol 11 (2) ◽  
Author(s):  
T. Gopalakrishnan ◽  
R. Saravanan ◽  
K. Karunakaran
Keyword(s):  
Numerical Investigation ◽  
Aircraft Design ◽  
Technical Note ◽  
Landing Gear ◽  
The Other ◽  
Fatigue Load ◽  
Landing Gears ◽  
Functional Components

In aircraft design functional components are of top priority. This numerical investigation is used for evaluating the fulfilment of strength requirement of the landing gear toggle assembly. The landing gear is the structure which supports the aircraft and helps in taxiing, take-off and landing of the aircraft. Hence it is suffered by more fatigue load than the other applications. The replacement of steel to aluminium was investigated. Every part is individually analysed and its part with sub-assemblies also investigated.

scholarly journals Technical Note: On the puzzling similarity of two water balance formulas – Turc–Mezentsev vs. Tixeront–Fu

2019 ◽  
Vol 23 (5) ◽  
pp. 2339-2350 ◽  
Author(s):  
Vazken Andréassian ◽  
Tewfik Sari
Keyword(s):  
Water Balance ◽  
Mathematical Reasoning ◽  
Technical Note ◽  
The Other ◽  
Partial Differential ◽  
Mathematical Properties ◽  
The Difference ◽  
The One

Abstract. This Technical Note documents and analyzes the puzzling similarity of two widely used water balance formulas: Turc–Mezentsev and Tixeront–Fu. It details their history and their hydrological and mathematical properties, and discusses the mathematical reasoning behind their slight differences. Apart from the difference in their partial differential expressions, both formulas share the same hydrological properties, and it seems impossible to recommend one over the other as more “hydrologically founded”: hydrologists should feel free to choose the one they feel more comfortable with.

scholarly journals Technical note: Evaluation of three autoanalysers for use in chemical pathology

1990 ◽  
Vol 12 (5) ◽  
pp. 189-194 ◽  
Author(s):  
E. M. Narebor
Keyword(s):  
Technical Note ◽  
The Other ◽  
Laboratory Work ◽  
Throughput Time ◽  
Chemical Laboratory ◽  
Large Numbers

Three autoanalysers, the EPOS 5060, ERIS 6170 and the Analyst, were evaluated for their adequacy for use in laboratories attached to Saudi ‘polyclinics’. All the analysers showed comparable within-batch imprecision. The Analyst was found to be the most useful because it was simple and practical and because its throughput time was faster than the other two analysers. The EPOS 5060 would be more suitable for screening large numbers of samples for single parameters; and the ERIS 6170 essentially suits normal routine chemical laboratory work.

scholarly journals Experimental and numerical investigation of the sintering rate of snow

2013 ◽  
Vol 59 (214) ◽  
pp. 269-274 ◽  
Author(s):  
Alec Van Herwijnen ◽  
Daniel A. Miller
Keyword(s):  
Numerical Investigation ◽  
Power Law ◽  
Penetration Resistance ◽  
The Other ◽  
Snow Sample ◽  
Rate Of Increase ◽  
Wide Range ◽  
Snow Metamorphism ◽  
The Mean ◽  
Snow Samples

AbstractSintering rates in snow were investigated by measuring changes in penetration resistance with time and by using a numerical snow metamorphism model. Periodic Snow Micro Penetrometer (SMP) measurements were performed on uniform snow samples covering a wide range of densities. The mean penetration resistance of snow increased with time according to a power law with an average exponent of 0.18. Simulated changes in the bond-to-grain ratio for simplified spherical ice grains followed a power law with an average exponent of 0.18, showing that the mean penetration resistance, as measured with the SMP, closely relates to bond-to-grain ratio in snow. For lower-density snow samples, consisting mostly of dendritic snow morphologies, the measured increase in penetration resistance was lower. This is likely the result of two competing processes: (1) strengthening of the snow sample due to the creation and growth of bonds and (2) weakening of the snow sample due to the formation of unbonded small rounded particles at the expense of larger dendritic forms. On the other hand, the rate of increase in penetration resistance for snow samples consisting of closely packed depth hoar was similar to that of rounded grains.

scholarly journals Scenario Approach to the Development and Use of Learning Management System in Universities

2017 ◽  
Vol 22 (6) ◽  
pp. 45-55 ◽  
Author(s):  
Y.G. Martyushova
Keyword(s):  
Management System ◽  
Learning Management System ◽  
Educational Process ◽  
The Other ◽  
Learning Management ◽  
The One ◽  
Main Component ◽  
Functional Components ◽  
Knowledge Evaluation ◽  
Scenario Approach

The article offers a scenario approach to the design of learning management system (LMS) structure. It is argued that the LMS structure and it functional components depend on the scenarios of its use in educational process which, in turn, are determined by the type of subject that is based on the main component of education content. There are three categories of the LMS users in the educational process in university: students, teachers, and administrators, and their roles differ from each other. The article provides detailed scenarios of how the LMS is used by various categories of users and describes the structure of the LMS in relation to these scenarios. On the one hand, the LMS represents a structured base of content: that is, it contains theoretical materials as well as tasks and exercises along with certain scales that reflect their difficulty. The weight of these tasks, initially determined by experts, can then be automatically corrected using the methods of mathematical statistics. On the other hand, implementing the described scenarios requires an electronic operating cover of the LMS, among the functions of which is the organization of control and self-checking, as well as providing storage and processing statistics of the LMS use. These statistics should then be automatically turned into the current rating of users which is important for knowledge evaluation and support of learning motivation in students during a semester.

Stabilization System for UAV Landing on Rough Ground by Adaptive 3D Sensing and High-Speed Landing Gear Adjustment

2021 ◽  
Vol 33 (1) ◽  
pp. 108-118
Author(s):  
Mikihiro Ikura ◽  
◽  
Leo Miyashita ◽  
Masatoshi Ishikawa
Keyword(s):  
Unmanned Aerial Vehicles ◽  
High Speed ◽  
Landing Gear ◽  
Detailed Measurement ◽  
Contact Points ◽  
Measurement Results ◽  
3D Sensing ◽  
Landing Gears ◽  
Spatio Temporal ◽  
Measurement Area

This paper proposes a real-time landing gear control system based on adaptive and high-speed 3D sensing to enable the safe landing of unmanned aerial vehicles (UAVs) on rough ground. The proposed system controls the measurement area on the ground according to the position and attitude of the UAV and enables high-speed 3D sensing of the focused areas in which the landing gears are expected to contact the ground. Furthermore, the spatio-temporal resolution of the measurement can be improved by focusing a measurement area and the proposed system can recognize the detailed shape of the ground and the dynamics. These detailed measurement results are used to control the lengths of the landing gears at high speed, and it is ensured that all the landing gears contact the ground simultaneously to reduce the instability at touchdown. In the experiment setup, the proposed system realized high-speed sensing for heights of contact points of two landing gears at a rate of 100 Hz and almost simultaneous contact on ground within 36 ms.

Design of Entrance Door Mechanism for Sabreliner Jet Aircraft

1996 ◽  
Author(s):  
Timothy J. Berg ◽  
Arthur G. Erdman
Keyword(s):  
Computer Software ◽  
Aircraft Design ◽  
The Other ◽  
Final Position ◽  
Open Door ◽  
Aircraft Cabin ◽  
Entrance Door ◽  
Improve Access

Abstract The redesign of the entrance door of a Sabreliner corporate jet to improve access to the aircraft cabin is described. The current aircraft design uses a door that opens into the cabin space allowing the top of the door to swing through the opening. The door rotates into its final position where it becomes the entrance steps to the aircraft cabin. In the present configuration, the open door is inclined 60° with the top step situated 14 inches above the cabin floor. This paper presents two new designs for the cabin door where the top step is reduced to the same height as the cabin floor. In addition, the incline of the steps has been reduced from 60° to about 45° improving access to the cabin. The final designs, developed using LINCAGES 4[1] and LINCAGES 6[2] computer software, are 6-bar mechanisms — one using pin joints and the other using a rotating slider link. In both cases, the floating coupler (the door) is driven by hand.

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