机翼包括注塑成型的可配置聚合物子组件的格子,设计用于在飞行期间改变形状。

麻省理工学院和NASA工程师设计轻型聚合物飞机机翼-复合材料网

来自美国宇航局艾姆斯研究中心(美国加利福尼亚州Moutain View)和马萨诸塞州马萨诸塞州麻省理工学院(麻省理工学院,马萨诸塞州,美国)的工程师团队已经建造并测试了一个由数百个微小相同的格子组装而成的飞机机翼。聚合物片。据报道,机翼可以改变形状来控制飞机的飞行。

机翼设计在NASA风洞中进行了测试,并在加利福尼亚州NASA Ames的研究工程师Nicholas Cramer共同撰写的“ 智能材料与结构 ”杂志的论文中进行了描述  。美国宇航局艾姆斯工程师和麻省理工学院校友Kenneth Cheung; 麻省理工学院的研究生Benjamin Jenett和其他八个人。

不像传统的机翼那样需要单独的可移动表面(如副翼)来控制平面的滚动和俯仰,新的装配系统可以通过结合刚性和柔性的混合使整个机翼或其部分变形成为可能。其结构中的组件。然后用作为框架的类似聚合物材料的薄层覆盖用螺栓连接在一起以形成开放的轻质网格框架的微小子组件。

研究人员说,结果是机翼比传统设计更轻,因此更节能,无论是金属还是复合材料。因为包括数千个火柴状支柱的数千个微小三角形的结构主要由空的空间组成,所以它形成机械“超材料”,其结合了橡胶状聚合物的结构刚度和气凝胶的极度轻盈和低密度。 。

Jenett解释说,每个飞行阶段都有一组不同的最佳机翼参数,以便为每个阶段提供更好的近似最佳配置。该系统设计用于通过以特定方式改变其形状来自动响应其空气动力学负载条件的变化。

几年前,Cheung和其他团队成员创建了一个长达一米的演示翼。新版本的尺寸大约是实际单座飞机机翼的五倍,其设计可通过自动装配机器人轻松完成。Jenett说,机器人装配系统的设计和测试是即将发表的论文的主题。

Jenett说,前一个机翼的各个部件都是用水刀系统切割的,制作每个部件需要几分钟。新系统采用注塑用聚乙烯树脂在一个复杂的3D模具,并产生每个部分 - 基本上由沿着每个边缘火柴尺寸支柱的中空立方体 - 只需17秒时,他说,这使它更接近可伸缩生产水平。

“现在我们有一种制造方法,”他说。虽然对工具进行了前期投资,但一旦完成,“部件便宜”,他说。“我们有盒子和盒子,都是一样的。”

他说,由此产​​生的晶格密度为每立方米5.6千克。作为比较,橡胶的密度为约1,500千克/立方米。“它们具有相同的刚度,但我们的刚度不到密度的千分之一,”Jenett说。

Jenett说,由于机翼或其他结构的整体结构是由微小的子单元构成的,因此机翼结构的整体设计可以从其传统的形状改变。研究表明,对于许多应用来说,集成的车身和机翼结构可以更加有效,他说,通过这个系统,可以轻松地构建,测试,修改和重新测试。

Jenett说,同样的系统也可用于制造其他结构,包括风力涡轮机的翼状叶片,其中现场组装的能力可以避免运输更长叶片的问题。正在开发类似的组件来构建空间结构,并且最终可以用于桥梁和其他高性能结构。

该团队包括康奈尔大学,加州大学伯克利分校,加州大学圣克鲁兹分校,美国宇航局兰利研究中心,立陶宛考纳斯理工大学和美国加利福尼亚州莫菲特菲尔德的合格技术服务公司的研究人员。这项工作得到了美国宇航局ARMD Convergent航空解决方案计划(MADCAT项目)和麻省理工学院钻头和原子中心的支持。

原文:

MIT and NASA engineers design lightweight polymer airplane wing

The wing, comprising a lattice of injection-molded, configurable polymer subassemblies, is designed to change shape during flight.

A team of engineers from NASA’s Ames Research Center (Moutain View, Calif., U.S.) and the Massachussetts Institute of Technology (MIT, Cambridge, Mass., U.S.) have built and tested an airplane wing assembled from a lattice comprising hundreds of tiny identical polymer pieces. The wing reportedly can change shape to control the plane’s flight.

The wing design was tested in a NASA wind tunnel and is described in a paper in the journal Smart Materials and Structures, co-authored by research engineer Nicholas Cramer at NASA Ames in California; NASA Ames engineer and MIT alumnus Kenneth Cheung; MIT graduate student Benjamin Jenett and eight others.

Instead of requiring separate movable surfaces such as ailerons to control the roll and pitch of the plane, as conventional wings do, the new assembly system makes it possible to deform the whole wing, or parts of it, by incorporating a mix of stiff and flexible components in its structure. The tiny subassemblies, which are bolted together to form an open, lightweight lattice framework, are then covered with a thin layer of similar polymer material as the framework.

The result is a wing that is lighter, and thus more energy-efficient, than those with conventional designs, whether made from metal or composites, the researchers say. Because the structure, comprising thousands of tiny triangles of matchstick-like struts, is composed mostly of empty space, it forms a mechanical “metamaterial” that combines the structural stiffness of a rubber-like polymer and the extreme lightness and low density of an aerogel.

Jenett explains that there is a different set of optimal wing parameters for each phase of flight, to provide a better approximation of the best configuration for each stage. The system is designed to automatically respond to changes in its aerodynamic loading conditions by shifting its shape in specific ways.

A meter-long demonstrator wing was created by Cheung and other team members a few years ago. The new version, about five times as long, is comparable in size to the wing of a real single-seater plane and is designed to be easily accomplished by autonomous assembly robots. The design and testing of the robotic assembly system is the subject of an upcoming paper, Jenett says.

The individual parts for the previous wing were cut using a waterjet system, and it took several minutes to make each part, Jenett says. The new system uses injection molding with polyethylene resin in a complex 3D mold, and produces each part — essentially a hollow cube made up of matchstick-size struts along each edge — in just 17 seconds, he says, which brings it much closer to scalable production levels.

“Now we have a manufacturing method,” he says. While there’s an upfront investment in tooling, once that’s done, “the parts are cheap,” he says. “We have boxes and boxes of them, all the same.”

The resulting lattice, he says, has a density of 5.6 kilograms per cubic meter. By way of comparison, rubber has a density of about 1,500 kilograms per cubic meter. “They have the same stiffness, but ours has less than roughly one-thousandth of the density,” Jenett says.

Because the overall configuration of the wing or other structure is built up from tiny subunits, the overall design of the wing structure could be changed from its traditional shape, Jenett says. Studies have shown that an integrated body and wing structure could be far more efficient for many applications, he says, and with this system those could be easily built, tested, modified and retested.

The same system could be used to make other structures as well, Jenett says, including the wing-like blades of wind turbines, where the ability to do on-site assembly could avoid the problems of transporting ever-longer blades. Similar assemblies are being developed to build space structures, and could eventually be used for bridges and other high-performance structures.

The team included researchers at Cornell University, the University of California at Berkeley, the University of California at Santa Cruz, NASA Langley Research Center, Kaunas University of Technology in Lithuania, and Qualified Technical Services Inc., in Moffett Field, Calif., U.S. The work was supported by NASA ARMD Convergent Aeronautics Solutions Program (MADCAT Project) and the MIT Center for Bits and Atoms.