Structural Development of an Eco-Efficient Commercial Aircraft

航空是温室气体（GHG）增长最快的来源之一。目前，该行业占全球温室气体排放量的4.9%。此外，这种情况是不可持续的，因为在2014年的一份报告中，波音公司表示，到2033年，航空旅行的需求预计将以每年5.4%的速度增长。这一形势凸显了我国发展生态经济型民用飞机的必要性。通过设计新颖的飞机结构和显著减轻飞机重量，可以实现这一目标。混合翼身（BWB）结构由于其燃油效率而被提出用于下一代客机。以前，我开发了解决BWB飞机机身复杂性的结构建模和分析方法。目前，我正在将注意力转向飞机重量，这对其环境效益有很大影响。我建议使用增材制造的晶格材料来建造机身的初级结构。然而，随着期望的重量减轻和随之而来的机身灵活性，在结构分析的各个阶段，考虑到机身几何和惯性非线性及其对飞机气动弹性响应和飞行动力学的影响，开发高保真设计载荷至关重要。人们在研制重量最小的飞机方面做出了显著的努力。然而，大多数现有的开发都考虑了一组确定性的临界载荷来进行结构优化。然而，飞机设计是多学科的。优化后的结构改变会产生新的质量和刚度分布，从而改变飞机的动力响应和载荷。这导致其他研究人员考虑负载的不确定性，这些不确定性最终会导致飞机设计的性能不理想。事实上，这一重大挫折导致加拿大航空航天工业的飞机开发计划长期拖延，使我们的经济损失数十亿美元。其中，详细设计阶段的结构优化采用飞机初步模型生成的临界载荷工况，认证载荷采用飞机优化模型生成。后者产生的荷载必须低于前者，但通常情况下并非如此。为了克服这一问题，我建议将飞机载荷分析纳入其结构优化过程。虽然这意味着一条计算成本昂贵的路线，但将开发一种有效的算法来确定基于给定质量和刚度分布产生临界载荷的机动类型，而无需进行全方位的载荷分析。如果成功，它将大大减少负载分析的规模，使所提出的过程可行。新工艺将根据工业标准开发，并将用于增材制造晶格材料制成的机身的多尺度优化。

Aviation is one of the fastest growing sources of Greenhouse Gases (GHG). Currently, the sector accounts for 4.9% of worldwide GHG emissions. Moreover, this situation is not sustainable as in a 2014 report, Boeing indicated that demand for air travel is projected to increase at 5.4% a year until 2033. This situation emphasize our need to develop ecological and economical civil aircraft. A step change towards that goal may be realized through designing novel aircraft configurations and significantly reducing aircraft weight. Blended Wing Body (BWB) configuration is proposed for next generation of airliners due to its fuel efficiency. Formerly, I developed structural modeling and analysis methodologies addressing airframe complexity of BWB aircraft. Currently, I am turning my attention to aircraft weight which considerably affects its environmental effectiveness. I propose to build airframe primary structures using additively manufactured lattice materials. However, with expected weight reduction and consequent airframe flexibility, it is critical to develop high fidelity design loads at all stages of structural analysis taking into consideration airframe geometrical and inertial non-linearity and their effect on aircraft aeroelastic response and flight dynamics. Notable efforts are made toward developing aircraft with minimized weight. However, most of existing developments considered a deterministic set of critical loads for structural optimization. Nevertheless, aircraft design is multidisciplinary. Structural modification due to optimization results in new mass and stiffness distribution that changes aircraft dynamic response and loads. This led other researchers to consider uncertainties in loads which ultimately generate aircraft design with off-optimal performance. In fact, this critical setback results in long delays in aircraft development programs in Canadian aerospace industry which costs our economy billions of dollars. There, structural optimization at detailed design is conducted using critical load cases generated by preliminary aircraft model while certification loads are generated employing aircraft optimized model. Loads generated by the latter must be lower than those of the former which is not often the case. To overcome this issue, I propose to integrate aircraft loads analysis into its structural optimization process. While this suggest a computationally expensive route, an efficient algorithm will be developed to determine type of maneuvers that will generate critical loads based on a given mass and stiffness distribution without the need to run a full range of loads analyses. If successful, it will reduce size of loads analysis drastically making proposed process feasible. The new process will be developed with industrial standards and will be used for multiscale optimization of airframe made of additively manufactured lattice materials.