Abstract

New modes of transportation systems are under intensive development because traditional systems fail to become mass transportation means due to their technological limitations. To meet the growing demand for VTOL vehicles, a novel VTOL technology, reciprocating-airfoil (RA) driven VTOL aircraft, had been introduced. The objective of this study is to model a crankshaft to structurally determine the feasibility of using a crankshaft structure as the reciprocating driver of this novel VTOL technology. Unlike the conventional crankshaft IC engines or compressors, the crankshaft system herein is a reciprocating driver to generate long-stroke reciprocating motion of the wings for VTOL vehicle operations. The unique challenges of this study are the exceedingly long crank arms and stringent weight minimizations that require the use of high-strength carbon fiber materials. The crankshaft model is geometrically designed by using SOLIDWORKS design software, and the commercial Ansys Mechanical Solver has been selected for the FEM structural analysis. Based on the nonlinear static analysis results, the maximum stress is developed at the junctions between the main shaft and the middle crank web. However, all of the determined deformation, stress, and strain under the current loading conditions as well as weight requirement is acceptable. Also, according to the modal analysis result, the possible resonance chance is low. In conclusion, this study provides a pathway for the final development of the novel reciprocating airfoil VTOL technology.

摘要

由于传统系统由于技术限制而未能成为大众交通方式，因此新型交通系统正在大力发展。为了满足对 VTOL 车辆不断增长的需求，引入了一种新颖的 VTOL 技术，即往复翼型 (RA) 驱动的 VTOL 飞机。本研究的目的是对曲轴进行建模，从结构上确定使用曲轴结构作为这种新型 VTOL 技术的往复驱动器的可行性。与传统的曲轴内燃机或压缩机不同，这里的曲轴系统是往复式驱动器，用于产生用于垂直起降飞行器操作的机翼的长冲程往复运动。这项研究的独特挑战是超长的曲柄臂和严格的重量最小化，需要使用高强度碳纤维材料。采用SOLIDWORKS设计软件对曲轴模型进行几何设计，并选用商用Ansys Mechanical Solver进行有限元结构分析。根据非线性静力分析结果，最大应力出现在主轴和中间曲柄腹板之间的连接处。然而，在当前负载条件以及重量要求下确定的所有变形、应力和应变都是可接受的。另外，根据模态分析结果，可能发生共振的机会很低。总之，本研究为新型往复式翼型垂直起降技术的最终发展提供了一条途径。