![]() ![]() In addition, the absolute values of the aerodynamic resistances of the upper and lower arms under the knuckle-upstream operating conditions are greater than those under the knuckle-downstream operating conditions. The change of diameter has a great influence on the aerodynamic lift forces of the upper and lower arms and a small effect on the aerodynamic resistances. The aerodynamic resistance of the bar of the lower arm accounts for 10%-25% of that of the lower arm, and the aerodynamic lift force accounts for 43%-68% of that of the lower arm under the two conditions. The aerodynamic resistance of the bar of the upper arm only accounts for 3%-10% of that of the upper arm, and the aerodynamic lift force accounts for 26%-55% of that of the upper arm under both the knuckle-downstream and knuckle-upstream operating conditions. Moreover, both the aerodynamic lift force of the upper arm and the aerodynamic uplift of the pantograph lessens with the increase of the upper arm diameter and raises with the increase of the lower arm diameter under the knuckle-upstream operating conditions. Research results show that both the aerodynamic lift force of the upper arm and the aerodynamic uplift force of the pantograph are larger with the rise of the upper arm diameter and are smaller with the rise of the lower arm diameter under the knuckle-downstream operating conditions, but the effect of the lower arm diameter on the aerodynamic uplift force of the pantograph is small. The aerodynamic uplift forces of pantographs were calculated by using the multi-body dynamics method, and the effects of the upper and lower arm diameters on the aerodynamic performances and aerodynamic uplift forces of pantographs were studied from the perspective of the aerodynamic force and flow field characteristics. The prospect of this research area is discussed.The pantograph models for the upper arms with seven different diameters and those for the lower arms with seven different diameters were built, and the aerodynamic numerical simulations of pantographs were carried out. The status of intelligent design of advanced structural materials based on data-driven methods is introduced. Various mainstream design methods are compared and illustrated. Hence, this paper systematically reviews the development of advanced structural material design methods. Data-driven methods can establish complex relationships of multi-dimensional variables, and they can reveal mechanical mechanisms and laws that are difficult to be discovered by traditional methods. However, the existing topology optimization methods still have challenges in achieving accurate reverse designs. ![]() For these reasons, the topology optimization method has been successfully applied to the design of advanced structural materials such as phononic crystals, cellular materials, etc. ![]() To traverse the design space to search for the optimal design by trial and error is also not practical. Nevertheless, it isn't easy to obtain the optimal designs only based on ingenious design. In the early material design, some researchers created reasonable mathematical and mechanical models from the natural topologies some researchers established bionic mechanical models based on the structural and functional characteristics of biological systems. These materials generally achieve excellent performances via structural design at multiple length-scales. Advanced structural materials have received extensive attention in the field of materials and structural design in recent years. ![]()
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