Certain Type Of Aircraft Research Articles

Damage distribution of composite structures of a certain type of aircraft

Aiming at the damage and repair of aircraft composite structures, the applications and damage of composite structures in a certain type of aircraft, including the wing, fuselage and other components, were counted. Solid laminates (integral panels) and sandwich laminates are typical composite structural forms in the aircraft. Structural damage distribution models with time variable were established, and then the damage distributions of the structures were fitted and tested by structural methods. The results show that the quantitative proportions of damage are 75% for skin delamination, 20% for stringer delamination and 4% for stringer debonding. Lognormal distribution, Weibull distribution and Gamma distribution can all be used to fit the geometric parameter distributions of the three types of structural damage, in which the Lognormal distribution model has the best fitting effect. The distribution of structural damage geometric parameters of one aircraft does not vary with time, and the distributions of geometric parameters of the structural damage between the same type aircraft are also highly similar, which can be expressed in a unified function form.

Simplified modeling study of the forward fuselage structure based on the overall structural rapid design software for civil aircraft

Abstract In order to solve the problems of poor weight estimation accuracy and difficult layout design trade-offs in the concept demonstration and overall program definition stage of civil aircraft, Aircraft Layout, a civil aircraft overall program structure rapid design software, is used to establish a numerical calculation-based layout program rapid design simulation platform. Based on the forward fuselage structure, this paper gives the results of rapid modeling and finite element simulation and analysis of the forward fuselage isotropic section of a certain type of aircraft, which provides a reference for the optimization design of the structural components of the forward fuselage section of a certain type of aircraft in the conceptual scheme design stage.

Uncertainty analysis method of high-speed wind tunnel standard model test results based on GUM and MCM

Abstract The standard model is a standard calibration model that has a well-known geometric shape and can represent the aerodynamic layout characteristics of a certain type of aircraft. It has many functions, including evaluating the accuracy of wind tunnel test data, verifying the integrity of the wind tunnel flow field and measurement system, and developing and verifying wind tunnel test technology. Conducting wind tunnel tests using standard models is a key step in realizing the functions of standard models. However, all existing literature on standard model tests has not effectively evaluated the uncertainty of the test results, which makes it impossible to evaluate the reliability of the test results. Based on the GUM and MCM uncertainty analysis methods, this paper establishes a method for quantitatively evaluating the uncertainty of the test results of high-speed wind tunnel standard model tests through rigorous mathematical derivation, providing technical support for precisely quantifying the uncertainty of standard model test results.

Research on DSP-based data model identification and triple-loop PID control of electro-hydraulic actuators

This paper focuses on the electro-hydraulic actuator of a certain type of aircraft, detailing the DSP-based hardware structure and principles. The study utilizes data acquisition and data model identification to establish a second-order model for the electro-hydraulic actuator. Verification sets and mean squared error (MSE) calculations, with an MSE value of 0.0110, indicate a reasonable identification model. Subsequently, a controller design structure is proposed based on the identified model. Finally, simulations validate the identified model and the triple-loop PID control. Experimental results show that the system's sine response output amplification factor is 0.9242.

Design and Implementation of Simulation Training System for Ground Maintenance Pannel of a Certain Type of Aircraft

According to the design requirements of ground maintenance pannel simulation training system of a certain type of aircraft, a set of training system with the functions of ground handling practice, aircraft maintenance operation training and PMA interactive operation training is developed. The system design fully considers the requirements of generalization and modularization design. The function division of each module is clear, the signal interface is clear, and one of the modules can be replaced quickly to facilitate the positioning and elimination of failure. It has the dual expansibility of training task and training model, and can continuously add training task package, including procedure training, troubleshooting guidance training, etc., and can adapt to change in aircraft state.

Prediction of aircraft cabin noise by statistical energy analysis

The noise level in the aircraft cabin is an important indicator on market competitiveness, and it is a considerable challenge to reduce the noise in the cabin at a relatively small cost, so efficient and accurate forecasting tools are required. In the aviation industry, Statistical Energy Analysis (SEA) is widely used to predict mid- and high-frequency noise in aircraft cabins. It has the advantages of simple method and low requirement of structure details. This paper models the cabin of a certain type of aircraft, and uses statistical energy methods to predict the noise level in the cabin during ground and cruise conditions. Among them, the prediction result of the cabin noise on the ground is in good agreement with the test results above 250Hz, which verifies the correctness of the model. During cruise, the pressure fluctuation on the outer surface of the front fuselage is dominated by turbulent boundary layer noise. The analysis shows that the Robertson model can predict turbulent boundary layer noise well, and the difference between the predicted single-point spectrum and the experimental value is less than 1dB. The cabin noise predicted by only loading the turbulent boundary layer noise source is consistent with the experimental results, but the sound pressure level in some frequency bands is low.

Simulation experiment on support strength of aircraft structural components

The design principles of strength test support methods for aircraft structural components were introduced in this paper. Aiming at the vertical tail static test of a certain type of aircraft, a supporting stiffness simulation method was invented, and a support fixture was designed. The supporting stiffness was accurately simulated by stiffness strength. The research results of this paper provide an important reference for the research of static test support methods for similar aircraft structural components.

Approach and Landing Energy Prediction Based on a Long Short-Term Memory Model

The statistical analysis of civil aircraft accidents reveals that the highest incidence of mishaps occurs during the approach and landing stages. Predominantly, these accidents are marked by abnormal energy states, leading to critical situations like stalling and heavy landings. Therefore, it is of great significance to accurately predict the aircraft energy state in the approach and landing stages to ensure a safe landing. In this study, a deep learning method based on time sequence data for the prediction of the aircraft approach and landing energy states is proposed. Firstly, by conducting an extensive overview of the existing literature, three characteristic parameters of altitude, velocity, and glide angle were selected as the indicators to characterize the energy state. Following this, a semi-physical simulation platform for a certain type of aircraft was developed. The approach and landing experiments were carried out with different throttle sizes and flap deflection under different wind speeds and wind directions. Then, a deep learning prediction model based on Long Short-Term Memory (LSTM) was established based on the experimental data to predict the energy state indicators during the approach and landing phases. Finally, the established LSTM model underwent rigorous training and testing under different strategies, and a comparative analysis was carried out. The results demonstrated that the proposed LSTM model exhibited high accuracy and a strong generalization ability in predicting energy states during the approach and landing phases. These results offer a theoretical basis for designing energy early warning systems and formulating the relevant flight control laws in the approach and landing stages.

Research on kinematics modeling and path planning of a hyper-redundant continuum robot

It has always been the case that work in confined spaces has high difficulty and complexity, and robots are usually required to replace humans to perform the corresponding operations. For the maintenance work in the fuel tank of a certain type of aircraft, a continuum robot with 32 staggered orthogonal joints is designed in this paper. To solve the motion problem of this robot, this paper combines the end-following method with the Jacobi inverse kinematics method, and proposes an end-following-segmented Jacobi method, which improves the accuracy and efficiency of the inverse kinematics solution. A ray path-planning algorithm for continuum robots is proposed for the job requirements of this robot and the specific operating environment inside an airplane fuel tank, and it is compared with the rapidly-exploring random trees (RRT) algorithm and particle swarm optimization (PSO) algorithm. The experimental results show that the planning time of the ray path-planning algorithm is less compared with the RRT algorithm and the PSO algorithm, and the paths obtained are shorter. Finally, a path-following simulation is performed on a 32-joint continuum robot model to verify the followability of the ray path algorithm.

Risk and preventing of COVID-19 grounded aircraft-value, risks and resilience: an ongoing debate

ABSTRACT Design/methodology/approach This paper used pervious related to aviation literatures to summarise and viewpoint the current aviation environment and conduct the risks, value, and resilience of grounded aircraft-value in the post-pandemic era. Purpose Throughout 2020 to date, this major event, known as SARS CoV-2, has had a decisive impact on global air transport. Since the outbreak began, passenger travel has declined due to infection risks and new laws and travel restrictions. Dependent Surveillance-Despite the recent recovery in demand from the airline industry, risks posed by new models remain a concern for many airlines. From the data of Broadcasting (ADS-B) is helpful for preliminary observation and judgment of the value level of a certain type of aircraft. Findings This paper not only focuses on the aviation environment, but discusses aviation highlights such as international perspectives, domestic (i.e. Taiwan) perspectives, and several issues between industry and academic perspectives. Research limitations/implications The next phase of research needed in this area is a closer assessment of the value of aircraft in the development of global networks, which could have important policy implications for aircraft manufacturers and the aviation industry. Originality/value This paper provides a contemplative perspective about the aviation industry.

Ditching characteristics of civil aircraft with low-tail layout

Research focusing on the multi-phase coupling problem and ditching performance of a certain type of aircraft was carried out by the volume of fluid model and full-flow moving mesh method. Compared with the experimental results of the scaled model, the pressure predicted by this method matches well, and the maximum error of the pitch angle is less than 1.5°, which can accurately reflect the movement and load characteristics of the aircraft during ditching. On this basis, the influence of flat tails, flaps, and nacelles on the ditching performance is analyzed. The results show that it is not conducive to maintaining a stable attitude if the deflection of the flat tail is too slight, and the advance water-entry of flaps and nacelles will accelerate the decreasing process of pitch angle.

Civil aircraft brake energy scenario selection and analysis method

This paper expounds the method of determining the civil aircraft brake energy scenario. Brake energy is an extremely important requirement for the carbon disc and fusible plug design of the civil aircraft brake system. In order to determine the brake kinetic energy capacity, following conditions should be considered: designed landing-stop condition, normal landing stop condition, reject takeoff condition and the most severe landing stop condition. As the most severe condition is related to the operational environment, emergency events, the aircraft architecture and system failure conditions, the essay illustrates the principles of how to select the correct scenario, the factors to be considered and the potential most severe condition. With the brake kinetic energy calculation method and the data of a certain type of aircraft, the paper finds out 2 conditions could be the most severe ones for brake energy calculation.

Research on Oxygenation Components under a High-Pressure Oxygen Environment

Oxygen nozzles play an important role in aircraft oxygen systems, and the oxygen valve is one of the most important components of the oxygen nozzle. In order to investigate the ignition source of three fires of a certain type of aircraft, combustion analysis, energy spectrum analysis, and material analysis were conducted. Based on the results of the analysis, oxygen impact tests were carried out under different conditions to identify the superior material and to calculate the lifetime of a PA1010 oxygen valve. The test platform was constructed at the National Key Experimental Base of Fire Science. The PA1010 oxygen nozzle and the F3 oxygen nozzle were the main test subjects. The test results show that the lifetime of the PA1010 oxygen valve under high-pressure oxygen was about 2532, and F3 was the safer material for the oxygen valve. This research provides a reference for the safety design of oxygen valves under high-pressure environments and facilitates further research into aircraft oxygen systems.

Application and Research of High-Pressure Energy Storage Technology in Aircraft Hydraulic System

The power demand of the hydraulic system in a certain type of aircraft was analyzed. Within the current design of the hydraulic system, the instantaneous power shortage is inevitable in the launching stage. In order to achieve instantaneous high power and improve the performance of the aircraft, a new scheme in which a new type of pressure boost accumulator was applied as a power compensation device was suggested in this work. The accumulator volume was optimized and its effect on the system was investigated using the whole hydraulic system model implanted in AMEsim software. Based on the requirement of the weapon hatch, the parameters of the pressure boost accumulator were simulated and determined. The simulated results showed that the pressure boost accumulator could be low-power charged and output instantaneous high power to drive the weapon hatch. This new scheme can be applied to decrease the installed power of the hydraulic system.

Study on the Crashworthiness Performance of A Cargo Hold Support Column of A Civil Aircraft

With the continuous development of China’s general aviation industry, there are urgent requirements for research on aircraft crashworthiness to provide better safety for aircraft occupants. According to the results of long-term crash investigations, if crash safety design is taken into account at the earliest stages of aircraft design, most accidents will become viable or partially survivable, which can greatly improve the survival rate of aircraft passengers after an accident. In this paper, the design criteria and design methods for crash resistance technology of aircraft cargo uphold pillars are studied, and the crash simulation analysis of a certain type of aircraft is analyzed. First, a feasible design method and optimization principle are formulated according to the specific characteristics of a certain type of aircraft; Then, the crash resistance characteristics of a certain type of aircraft are analyzed, and the finite element model of the fuselage and cargo uphold pillars structure is established based on the three-dimensional electronic prototype of the aircraft. By the crash conditions specified in the relevant specifications, a mechanical simulation study of the aircraft is carried out, and the results are analyzed. Finally, constructive comments are given based on the simulation results. The reliability of the design is verified using simulation analysis, which provides a reference for the simulation and analysis of the anti-crash design of the aircraft cargo uphold pillars structure.

Study on Health Monitoring and Fatigue Life Prediction of Aircraft Structures

In this paper, some progress and achievements in aircraft integrity requirements, structural health monitoring, load spectrum measurement and life assessment research were presented. Several concepts of structural health monitoring were analyzed and compared, and the basic flow chart for health monitoring and life prediction of an aircraft structure was given. The selection of control points, construction of load/strain equations and stress calculation of control points were also described. Reliable IAT (Individual Aircraft Tracking) and life monitoring methods and software for IAT were developed for a certain type of aircraft, and fatigue life prediction of an aging aircraft was conducted based on actual measurement of load spectrum. The main features such as damage calculation, life evaluation and result output were discussed, and the future research focuses relating to intelligent structural health monitoring were finally explored.

The modeling and analysis of dynamic characteristics of the aircraft wheels

In the paper, dynamic characteristics of aircraft wheels are analyzed through building mathematical model of vertical force, longitudinal resistance force, and lateral force of aircraft wheels. Simulation software of force properties of aircraft wheels is developed based on a certain type of aircraft. Finally with the software loaded into an engineering simulator and tested, the accuracy and effectiveness of the software are evaluated according to simulation results.

Research on the layout plan of inerting gas filling inlet and outler of a complex fuel tank

According to the inert gas filling requirements of a certain type of aircraft fuel tank, three different inlet and outlet layout plans are designed. Based on CFD, the simulation calculation of the inert gas filling effect of the fuel tank under different inlet and outlet layout plans is calculated. The changes of the oxygen volume fraction (Vo2) in the gas space in the tank under different inert gas flow rates, concentrations and fuel load are analyzed. The calculations show that with the increase of inerting time, the average Vo2 in the tank decreases, and finally tends to the Vo2 of inert gas. Considering the overall average Vo2 of the tank and the uniform distribution of inert gas in the gas space of each tank, it can be seen that the best inerting performance can be achieved by adopting the inlet and outlet layout plan 3. The calculation results can provide a basis for the optimization of the gas distribution design of the tank inerting system.

Research on multi-physical domain modelling and simulation technology of electromechanical system based on bond graph

In order to combine virtual and real simulation of physical domain controlled object model of electromechanical system with real airborne electronic equipment, the physical domain controlled object of electromechanical system of a certain type of aircraft is taken as the research object. Based on bond graph theory, the model of physical domain of electromechanical system including mechanical, hydraulic and thermodynamics is constructed, and the HiL simulation of electromechanical management strategy is completed. Compared with flight parameters, it is shown that the model based on bond graph is suitable for complex airborne electromechanical system, and the simulation model can clearly express the energy transfer, conversion, storage and dissipation in the electromechanical system, which is of great significance for improving the design efficiency of military aircraft.

Damage tolerance analysis of wading structures of amphibious aircraft based on Franc3D

Aiming at the combined action effect of the corrosive environment of amphibious aircraft wading structures and random loads including water surface take-off and landing impact, based on the standard load spectrum TWIST of transport aircraft, considering the load level and frequency corresponding to the hydrodynamic load, the simulated random load spectrum of the wading structure was first compiled; the Willenborg/Chang high-load hysteresis model was used to consider the hysteretic effect of hydrodynamic high-amplitude overload on structural crack propagation, and an engineering method for damage tolerance analysis of amphibious aircraft wading structures was established. Taking the common hole edge crack of a typical wading structure of a certain type of aircraft as an example, based on the Franc3D crack propagation analysis software, the crack propagation life under the combined action of corrosive environment and random load spectrum was analyzed, and the inspection threshold value and check interval for maintaining the airworthiness of the structure were determined by residual strength analysis. The method proposed in this study is simple and feasible, and provides a theoretical basis for the damage tolerance analysis and maintenance plan formulation of amphibious aircraft wading structures.