Composite materials are more and more widely used in the modern aircraft structure. In order to effectively forecast the health state of aircraft wing, the multivariate empirical mode decomposition (MEMD) energy entropy and extreme learning machine (ELM) model are introduced into prediction method o...

To overcome the shortcomings of linear Lamb waves in closed crack and micro crack monitoring, a imaging method of crack damage localization in plate-like structure based on vibro-acoustic modulation theory and delay and sum algorithm is proposed. The signal components of acoustic wave are analyzed i...

A photonic bandgap fiber collimator with C-lens was proposed. The photonic crystal fiber end face does not have reflection, so the transform matrix will change. From the general model of Gaussian-beam imaging, using the theory of matrix optics, the matrix optics was calculated in meridian plane and ...

A variable geometry turbocharger method was used to adjust the power of the engine. It's regulation law and characteristics was studied. According to the turbine flow model, the influence of different nozzle ring opening degrees on the turbocharger was analyzed under the same operating conditions. I...

Effective strategy of regenerative brake can increase the recycling energy and improve the driving range of electric vehicles. A recycling brake force distribution strategy on the basis of maximum boundary was proposed from the analysis of the vehicle brake dynamics and related regulations. The mode...

Aimed at the problem of attitude errors of distributed position and orientation system (POS) accumulate over time when airborne earth observation aircraft moves along a straight line at a constant velocity, a variety of maneuver modes were designed. Not only the estimation accuracy of distributed PO...

In order to enhance the stability and reliability of electron beam source system and improve the machining quality of electron beam, the topology circuit of AC-DC-AC-DC-AC-DC, new power transformer, high voltage pulse detection technology, optimized feedback control technology of electron beam and c...

The continuous trailing-edge variable camber wing has a potential in improving the aerodynamic characteristics of the airliner, and is widely concerned recently. Based on the optimization design system constructed in this paper, the influence of continuous trailing-edge variable camber wing on the a...

Investigation on the pitching moment non-linear characteristics of the high-attitude long-endurance (HALE) diamond joined-wing configuration unmanned aerial vehicle (UAV) was carried out by both numerical simulation and theoretical analysis method. The results show that the aircraft have two obvious...

TT messages that have the top priority among three kinds of traffics affect RC message communication inevitably in time-triggered Ethernet (TTE). Therefore, RC messages have to be scheduled among discrete time slices caused by TT message offline schedule table. A modified weighted round robin (MWRR)...

The DDES is a widely used approach among RANS/LES hybrid methods. It introduces the delayed function to ensure full RANS mode in the near-wall region, and has been proven to be quite efficient for separated flows. Up to date, various different delayed functions have been developed. However, the unde...

Due to the guidance law with terminal intercept angle which will cause big angle error when available payload is insufficient, a guidance law considering time-varying overload constraint has been elicited, which would bring on more energy loss when much maneuver is achieved at the same time. Given t...

Aimed at compressible multiscale flow simulations, a fifth-order high-resolution compact shock capturing scheme, compact-reconstruction weighted essentially non-oscillatory (CRWENO), is studied. Nonlinear weights are used to combine lower-order compact schemes to approximate a higher-order compact s...

In the application of global navigation satellite system-reflection(GNSS-R) technology, the reflection signal source is needed to test the receiver in order to reduce costs. The signal model is the core of GNSS-R signal source. In order to solve the problem of the lack of corresponding model, this p...

A two-step optimization strategy for the supercritical laminar flow airfoil design is proposed in the paper. The γ-Re_θt transition model coupled with the shear stress transportation (SST) turbulence model is used for prediction of airfoil boundary layer transition. The Class/Shape Transformation (CS...

For modeling, the existing spares-related researches have insufficient consideration of lateral transshipments. In this paper, the authors select a three-site inventory system as the research object, and by introducing spares supply support relationship between sites, longitudinal and lateral transs...

In order to keep the motility in the thin atmosphere, air vehicles usually employ reaction control system (RCS), but in supersonic flow, it leads to complex jet interaction flow field on the surface of air vehicles, which has enormous influence on flight control. In order to improve the regularity u...

When dealing with data association for unequal length sequence, single model cannot balance computational accuracy, complexity and disturbance rejection. So a data association algorithm for unequal length sequence based on multiple model (MM) was proposed. The two unequal length sequence similarity ...

The integrated structure and working principle of three phase induction motor-axial piston electro-hydraulic pump (EHP) were introduced. The mechanical losses were calculated. A model of EHP was established in Ansoft software, and then the electromagnetic losses were analyzed. Finite element couplin...

This paper introduces the traditional demodulation method of Fabry-Perot (F-P) sensors, and systematically derives the demodulation principle of three-wavelength digital phase demodulation method using extrinsic Fabry-Perot interferometer (EFPI) sensors. Meanwhile, simulation method has been used to...

Aimed at the difficulty to accurately predict the reliability life of smart meter in running state, based on the generalized multi-stress accelerated model, this study researched and determined the life distribution rules of smart meter by using the accelerated degradation test data. Through the ana...

Based on hydrogen-powered ultra-long endurance unmanned aerial vehicle (UAV), nonlinear static aeroelastic characteristics were analyzed by the strong-coupled method for its high-aspect-ratio light composite wing. The aerodynamic comparison of rigid and elastic (aeroelastic deformation) wing was inv...

Based on analysis of the structural and mechanical characteristics of the bearing with looseness on high-speed flexible rotor and the demand of dynamic optimal design for multi-supported flexible rotor, the mechanism of non-straight change of stiffness of supporting structure caused by looseness on ...

Based on the characteristics of transient communication signals and non-Gaussian noise, the corresponding signal models were established, and a novel algorithm of transient communication signal detection under non-Gaussian noise was proposed based on the improved Hilbert-Huang transform (HHT), which...

Interception of air targets requires zero miss-distance and impact angle constraint to improve the missile guidance performance. First, the acceleration of the target was estimated by extended disturbance observer which also considered the noise interference. Second, a nonsingular terminal sliding m...

For the structures with fuzzy uncertainty and random uncertainty simultaneously, to measure the influence of fuzzy and random input variables on the statistical characteristic of output response, a new global sensitivity index is proposed. Based on the definition of possibilistic moments of the fuzz...