Active disturbance rejection control (ADRC) is an advanced control technology, which does not depend on the precise model of the controlled object and can deal with external disturbance effectively. Therefore, in orde...
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The study of the interaction between laser and composite materials has attracted the attention of many researchers. In this paper, the surface morphology and temperature evolution of T300 carbon fiber composites irrad...
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In order to study the crashworthiness of civil aircraft fuselage section in typical runway crash environments, this paper takes the metal fuselage structure of a typical civil aircraft as the research object. The envi...
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Speed and oscillation frequency are two key factors that effect tyre lateral dynamic characteristics. Tyre models for previous landing gear shimmy analysis use stationary shape functions for the lateral tyre deformati...
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The armored structure is exposed to the outside of the target in the combat environment and becomes the primary target of fragmentation. In order to study the multi-mode damage caused by fragmentation, a set of multi-...
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Aircraft vulnerability modeling is the basis and prerequisite for vulnerability analysis. At present, vulnerability modeling methods include combinatorial geometry, triangular patch, and tetragonal patch. However, the...
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In this paper, a numerical simulation study is carried out on the aerodynamic characteristics of the aircraft wing surface after damage. The damage form is the wing perforation. To study the aerodynamic characteristic...
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Active disturbance rejection control (ADRC) is an advanced control technology, which does not depend on the precise model of the controlled object and can deal with external disturbance effectively. Therefore, in orde...
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ISBN:
(数字)9798331516611
ISBN:
(纸本)9798331516628
Active disturbance rejection control (ADRC) is an advanced control technology, which does not depend on the precise model of the controlled object and can deal with external disturbance effectively. Therefore, in order to solve the errors of glide path and flight path caused by wind disturbance during the automatic landing of civil aircraft, ADRC can be applied to the system. The second-order cascade LADRC systems of longitudinal and lateral directions are designed respectively, in which the attitude angle control is designed for inner loop and the position control is designed for out loop. The simulation shows that both cascaded LADRC and PID controllers have a certain inhibitory effect on wind disturbance. While the LADRC controller has smaller overshoot, stronger robustness, stronger course keeping ability and anti-interference ability. And the parameters of LADRC controller need to be adjusted are not too many, which meets the actual engineering requirements.
A generalized analytical model is developed to predict progressive failure behavior of several types of textile composites,including plain weave composites,twill weave composites,two-dimensional tri-axially braided co...
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A generalized analytical model is developed to predict progressive failure behavior of several types of textile composites,including plain weave composites,twill weave composites,two-dimensional tri-axially braided composites and warpreinforced 2.5-dimensional braided *** this model,the unit cell(UC)of composite is firstly identified and reconstructed into a refined lamina structure with multiple equivalent lamina elements(ELEs)based on apt geometrical approximation and ***,two-way coupled stress-strain responses within the UC(macro-scale)and ELE(meso-scale)are established through a universal series-parallel model(SPM).Finally,a progressive damage model,which consists of damage initiation criteria and a stiffness evolution strategy,is employed to predict damage behavior of the *** analytical results including mechanical properties and progressive failure process are validated against the existing numerical and experimental ones in *** validated analytical model is then used to study the effects of global fiber volume fraction,braided angle,shear failure coefficient and selected failure criteria on stiffness,strength and failure *** present results demonstrate the efficiency and generic capability of the present analytical model for predicting the mechanical responses of a range of textile composites.
In order to study the crashworthiness of civil aircraft fuselage section in typical runway crash environments, this paper takes the metal fuselage structure of a typical civil aircraft as the research object. The envi...
ISBN:
(数字)9781837240753
In order to study the crashworthiness of civil aircraft fuselage section in typical runway crash environments, this paper takes the metal fuselage structure of a typical civil aircraft as the research object. The environment models of the multi-layer structural runway, the off-runway soil and the rigid ground, and the structural model of the middle fuselage section of a certain type of civil aircraft were established. Furthermore, based on the simulation model, the effects of different ground environments on the fuselage section structural crashworthiness under the action of the vertical impact speed of 7m/s were studied by means of the finite element simulation method. The simulation results show that the mesh size of the ground environment has a significant effect on the calculation time; For asphalt concrete runway modeled based on the elastic layer theory, the thickness of the soil base is the key to the overall model dimensions; the multi-layer structural runway environment has a certain buffering effect on the structural collision process compared with the rigid surface environment; the surface icing runway environment has a smaller effect on the dynamic response of the fuselage section structure under vertical impact; while the off-runway soil environment has a stronger buffering effect, but it will change the way of energy absorption of the structure.
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