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Cao X.,The First Aircraft Institute | Yang J.,The First Aircraft Institute | Han X.,Northwestern Polytechnical University
Fuhe Cailiao Xuebao/Acta Materiae Compositae Sinica | Year: 2012

A kind of stitching line computation model was proposed to research the effect of stitching parameters on the strain concentration and stress concentration around the hole edge for the stitching-reinforced composite laminate containing a circular hole, such as the stitching needle distance, the row spacing, the edge distance and the modulus of stitching line, etc. The stress and strain distribution regularity around the hole edge and the nearby region were investigated analytically by combining the finite element computational results with experimental results, and an appropriate design method about the stitching parameter on the edge of hole as well as some pertinent conclusions was gaved. Research shows that different stitching parameters have obvious effect on the strain concentration and stress concentration around the hole edge.

Yin Z.,Northwestern Polytechnical University | Li Y.,The First Aircraft Institute | Tan S.,The First Aircraft Institute
Jixie Qiangdu/Journal of Mechanical Strength | Year: 2010

Under the abnormal landing, the aircraft structure must guarantee the safety of passengers according to China Civil Aviation Regulations 23(CCAR 23). For the first time, the crashworthiness model of some civil aircraft fuselage structure is carried out. The influence of crash velocity has been taken into account. Under different crash velocity, the acceleration of floor, impact force, and energy absorption capability have been analyzed. Numerical results show that horizontal velocity influences the impact force, energy absorption, and acceleration of the floor. And some horizontal velocity is beneficial for crashworthiness of the aircraft structure. And these provide a reference for reliability design and evaluation of this aircraft.

Yang C.-F.,The First Aircraft Institute | Zhang J.-Z.,Nanjing University of Aeronautics and Astronautics
Experimental Thermal and Fluid Science | Year: 2012

Experimental study was conducted to investigate the enhanced cooling performance caused by ridge-shaped tabs located along the upstream edge of the film cooling holes. Three covering ratios of ridge-shaped tab on film hole and four blowing ratios were considered in the present. The results show that the presence of ridge-shaped tabs in the nearby region of the primary film cooling holes mitigates the primary vortices due to mainstream-coolant jet interaction in the downstream region. The lower penetration of coolant jet provides an increment in the film cooling effectiveness and also enhance heat transfer coefficient over the baseline case. The ridge-shaped tabs provide enhancements in cooling effectiveness, but this is at the expense of larger pressure drop, especially for ridge-shaped tabs with bigger covering ratio. © 2011 Elsevier Inc.

Xiao H.,Xian University of Science and Technology | Gao C.,Xian University of Science and Technology | Dang Y.-Q.,The First Aircraft Institute
Shiyan Liuti Lixue/Journal of Experiments in Fluid Mechanics | Year: 2011

The waverider configuration is an important configuration of hypersonic cruise vehicle. Hypersonic flow around a multi-objective optimization designed waverider is experimentally studied by pressure measurement, force measurement and Schlieren observation at M=6 and 7 and angle of attack ranging from -4° to 8°. The results show that the aerodynamic characteristics of all the components of the waverider are good. The forebody precompression quality meets the design requirements well, the forebody shock is exactly caught by the lip of the inlet and the flow is quickly expanded at the aft body.

Fan Z.,Aerospace Research Institute of Materials And Processing Technology | Wang S.,Beijing Engineering and Technological Center for Advanced Aluminum Alloy Materials and Application | Lu Z.,Aerospace Research Institute of Materials And Processing Technology | Zhang P.,The First Aircraft Institute | Li H.,Beijing Institute of Technology
Tezhong Zhuzao Ji Youse Hejin/Special Casting and Nonferrous Alloys | Year: 2015

The components optimized design and performance analysis of Al-Si-Mg based alloy were investigated systematically by the orthogonal experimental design of the four factors to three levels, combined with the JMat-Pro material simulation software. The results show that the Si element has the strongest role for the cooling rate of Al-Si-Mg based alloy during the solidification process, followed by the Fe element and Ti element, whereas the Mg element exhibits the minimal impact. Mg has the most obvious effect on the yield strength, tensile strength and hardness (HRC) of Al-Si-Mg based alloy, followed by Fe element and Ti element, Si element. The tensile strength of the alloy is increased to 337.2 MPa from 175.2 MPa with the SDAS of the Al-Si-Mg based alloy decreased from 200 μm to 20 μm, where the Mg element is dominant role in the SDAS, followed by the Si element, Fe element and Ti element. After three step solid solution and the two step aging heat treatment, the average tensile strength, yield strength and elongation of Al-6.5Si-0.7Mg-0.2Fe-0.2Ti-0.1Zn-0.1Mn-0.1Cu alloy reach 371 MPa, 310 MPa and 5.84%, respectively, which is near to the calculation of JMat-Pro software. The structure of Si phase in the alloy at as-cast state exhibits plate-like or needle, while the morphology is converted into spheroidization ones gradually after heat treatment, and the fracture morphology is characterized by the dimple fracture. ©, 2015, Journal Office of Special Casting and Nonferrous Alloys. All right reserved.

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