摘要: Jiefang CA141 was selected as a representative vehicle, the four possible kinds of driving behaviors at climbing section were analyzed, and the acceleration was calculated based on the parameters of dynamics performance when vehicle shifted to accelerate or decelerate at climbing section.A 3D finite element model was established for the transient dynamics analysis of asphalt pavement under moving load.The compressive stresses, shear stresses and vertical displacement characteristics under different driving behaviors were analyzed.Calculation result shows that under the effect of moving load, the mechanics response of pavement structure not only has fluctuation, but also presents alternating feature within a certain region, and there is reversal of changes on tension and compression stresses in the area.Specifically, compressive stress concentrates in the area of 0~6 cm for road surface, the maximum shear stress moves from wheel joint to wheel centre as the speed of vehicle reduces and the horizontal force increases, and its peak shifts from middle surface layer to road surface along depth direction.The speed variation and low speed are the main reasons for pavement rutting at climbing section.更多>
摘要: A novel hydrodynamic layout based on anisomerous bow rudder was firstly proposed for strongly maneuvering underwater supercavitating vehicle because aft rudder is short of effectiveness.In the layout, straight-and-level flight and strong maneuverability motion were considered.Bow rudder with 2 DOFs controlled orientation with deflexion in level, and controlled pitching or depth with up-and-down motion.Anti-roll fin appended below the rudder generated imbalances torque.For validating the dynamic characteristic of the design layout, related simulation on a supercavitating vehicle was carried out.The attenuation of remanent roll moment completes in about 0.1 s, and ultimate roll angle is less than 0.1°.Analytical result shows that the novel layout can markedly improve control rudder effectiveness.更多>
