DESIGN OF FORCE MEASURING SYSTEM ON MAIN LANDING GEAR WEIGHT DROP TESTING MACHINE FOR THE APPLICATION OF LSU SERIES

In this research, the design of the force measuring system on main landing gear weight drop test for the LSU series that developed by LAPAN was carried out. The principle of this machine is to apply the load according to the weight of the aircraft on the main landing gear and drop it at a certain height assisted by the guiding rail. At the bottom of this machine there is a impact platform where each angle is mounted with a load cell that functions to measure the reaction force due to the impact of the main landing gear. In addition, there is a data acquisition system whose function is to process the output signal from load cell and display measurement data. The data acquisition system used consists of DAQ measurement hardware made by national instruments and LabVIEW software installed on a PC. The design of this testing tools aims to carry out a dynamic impact test on the main landing gear structure of the UAV. In this study, static calibration has also been successfully performed on the impact platform and shows consistent results for various test masses.

COMPARATIVE STUDY OF WING LIFT DISTRIBUTION ANALYSIS USING NUMERICAL METHOD

This research focuses on calculating the force distribution on the wings of the LSU 05-NG aircraft by several numerical methods. Analysis of the force distribution on the wing is important because the wing has a very important role in producing sufficient lift for the aircraft. The numerical methods used to calculate the lift force distribution on the wings are Computational Flow Dynamics (CFD), Lifting Line Theory, Vortex Lattice Method and 3D Panel Method. The numerical methods used will be compared with each other to determine the accuracy and time required to calculate wing lift distribution. Because CFDs produce more accurate estimates, CFD is used as the main comparison for the other three numerical methods. Based on calculations performed, 3D Panel Method has an accuracy that is close to CFD with a shorter time. 3D Panel Method requires 400 while CFD 1210 seconds with results that are not much different. While LLT and VLM have poor accuracy, however, shorter time is needed. Therefore to analyze the distribution of lift force on the wing it is enough to use the 3D Panel Method due to accurate results and shorter computing time.

DEPARTURE TRAJECTORY OPTIMIZATION FOR NOISE ABATEMENT PROCEDURE IN SOEKARNO-HATTA INTERNATIONAL AIRPORT

Air traffic noise emission has been a growing concern for communities living within the vicinity of airports due to a massive increase in air traffic volume in recent years. This work focuses on the noise annoyance problem by optimizing one of the RNAV trajectories, which aims to minimize the noise footprint of a flying aircraft in a low altitude trajectory. Optimal control theory is applied to minimize the number of awakenings caused by a departing aircraft while constraining the relative increase of fuel consumption with regard to a fuel-minimal trajectory. The aircraft simulation model is based on the BADA 3 database, while the noise is modeled according to the ANP database, both published by EUROCONTROL. The methodology is demonstrated for the Soekarno-Hatta International Airport (CGK) in Jakarta; the result shows the comparison between fuel-minimal trajectories and noise-minimal trajectories for seven aircraft types representing the fleet mix at CGK. The number of awakenings of the noise-minimal trajectories is reduced by 30.33%, with an additional of 5% fuel consumption for the seven aircraft types when compared to the fuel-minimal trajectory.

A FINITE ELEMENT ANALYSIS OF CRITICAL BUCKLING LOAD OF COMPOSITE PLATE AFTER LOW VELOCITY IMPACT

Composite is a material formed from two or more materials that macroscopically alloyed into one material. Nowadays, composite has been generally applied as lightweight structure of aircraft. This is due to the fact that composites having high strength-to-weight ratio. It means the composites have the capability to take on various loads, despite their lightweight property.Laminate composite is one type of composite that has been generally used in aircraft industries. This type of composite is susceptible to low-velocity impact induced damage. This type of damage can be happening in manufacture, operation, or even in maintenance. Low-velocity impact could cause delamination. Delamination happens when the plies of laminated composites separated at the interface of the plies. This type of damage is categorized as barely visible damage, means that the damage couldn’t be detected with visual inspection. Special method and tool would be needed to detect the damage. Delamination will decrease the strength of the laminated composite.Delamination can be predicted with numerical simulation analysis. With increasing capability of computer, it is possible to predict the delamination and buckling of laminated composite plate. This research presents the comparisons of buckling analysis results on laminated plate composite and damaged laminated plate composite. By the result of LVI simulation, it is shown that low velocity impact of 19.3 Joule causing 6398 mm2 C-Scan delamination area inside the laminated composite. The delamination causing structural instability that will affect buckling resistance of the plate. The result of analysis shows that the existence of delamination inside laminate composite will lower its critical buckling load up to 90% of undamaged laminate’s critical buckling load.Keywords : composite, laminate, delamination, buckling.

STABILITY AND CONTROLABILITY ANALYSIS ON LINEARIZED DYNAMIC SYSTEM EQUATION OF MOTION OF LSU 05-NG USING KALMAN RANK CONDITION METHOD

This paper discusses the stability, control and observation of the dynamic system of the Lapan Surveillance UAV 05-NG (LSU 05-NG) aircraft equation. This analysis is important to determine the performance of aircraft when carrying out missions such as photography, surveillance, observation and as a scientific platform to test communication based on satellite. Before analyzing the dynamic system, first arranged equations of motion of the plane which includes the force equation, moment equation and kinematics equation. The equation of motion of the aircraft obtained by the equation of motion of the longitudinal and lateral directional dimensions. Each of these equations of motion will be linearized to obtain state space conditions. In this state space, A, B and C is linear matrices will be obtained in the time domain. The results of the analysis of matrices A, B and C show that the dynamic system in the LSU 05-NG motion equation is a stable system on the longitudinal dimension but on the lateral dimension directional on the unstable spiral mode. As for the analysis of the control of both the longitudinal and lateral directional dimensions, the results show that the system is controlled.

NUMERICAL INVESTIGATION ON THE FUSELAGE AIRFRAME OF LSU 05 NG AIRCRAFT

In this paper, numerical investigation on the fuselage structure of LSU 05 NG was carried out. This fuselage is designed to carry the payload up to 30 kg. Statical numerical analysis using finite element method was done using Simulia Abaqus. The fuselage structure that has been design consists of frame, longeron, and skin that can also be semi-monocoque structure. This airframe use combination of balsa and GFRP type of composite as the material. There are three load case: take-off condition, cruise condition, and landing condition. Tsai-hill failure criteria is used to investigate the strength of the composite structure due to the load that applied. Maximum stress from this calculation is 48 Mpa at the ground condition (take-off and landing) while the cruise stress analysis is 16 Mpa. The maximum tsai-hill criterion is 0,83. With such simulation results it can be said that the fuselage structure is still safe when operated and can also be optimized for several components so that the weight of the aircraft can be reduced.

Analysis Ballistic Flight and Design of Control System RKX200TJ/Booster at Rocket Booster and Climb Phases

The problem encountered while developing the RKX-200TJ/booster is the measurement of mass vehicle (center of gravity). The thrust line of the rocket booster does not coincide with the center of gravity can induce a pitch disturbance. By controlling the pitch parameter, the pitch disturbance phenomenon can be minimized. In this paper is presented the flight performance and dynamics analysis and the design of pitch and roll control system for RKX200TJ/booster during rocket booster and climb phase. The result indicates that the pitch disturbance can be reduced until decrease about 27% whereas roll angle ( ) can be damped at zero level ( ). Pitch angle ( ) can be maintained at angle 5° for climb phase. Although the one of moment arm case shows the static instability and uncontrollability during rocket booster phase, the control system can control vehicle the further phase. This simulation presented in X-Plane and Simulink. The PID controller is selected in control system design.

Effect of Isomer Composition of Hydroxy Terminated Polybutadiene (HTPB) in Low Shear Flow Behavior (Efek dari Komposisi Isomer dari Hydroxy Terminated Polybutadiene (HTPB) terhadap Sifat Alir dalam Geseran Rendah)

HTPB is the ultimate component of matrix builder for high-filled composite materials. Flow behavior of HTPB in low shear is crucial in casting the composite. Considering the characteristics of hydrocarbon, this work aims to investigate the effect of microstructure composition of HTPB on its flow behavior. In this work, HTPB with different composition of 1,4-cis, 1,2-vinyl and 1,4-trans microstructures were used. Fourier-Transform Infra-Red spectroscopy (FT-IR) was used to determine the composition. It was calculated as a ratio of peak area of 710, 910 and 970 cm-1 for 1,4-cis, 1,2-vinyl, 1,4-trans isomers respectively. Viscosity was measured using a rotational viscometer at various low shear rates. It is found that HTPB with high 1,2-vinyl/1,4-trans isomers shows shear thickening behaviour, distinguished significantly from Newtonian flow of the others. It is suggested that mechanism of shear thickening involves a certain configuration of 1,2-vinyl and 1,4-trans isomers that builds different degrees of flow resistance from one to other shear layers. The configuration and flow resistance changes among layers as shear increases.