The thin-walled structure with lattice and stiffeners is a typical hybrid structure and effectively combines the load-bearing merits of lightweight lattices and thin-walled stiffened configurations, while demonstrating significant multifunctional potential that provides novel technical solutions for aerospace structural lightweighting. The increasing maturity of metal additive manufacturing technologies has laid a reliable foundation for the practical application of lattice structures. To facilitate the implementation of lattice structures in aerospace engineering, this paper focuses on thin-walled structures with lattice and stiffeners, primarily from the perspective of load-bearing structural design and its practical applications. Building upon the joint team's recent exploratory applications, this paper systematically outlines four critical aspects: fundamental characteristics of lattice structures, macroscale mechanical analysis methodologies, design of the lattice Representative Volume Element (RVE), eptimization design methodologies for thin-walled load-bearing structures with lattice and stiffeners. These systematic analyses aim to establish comprehensive reference guidelines for engineering designers. Furthermore, based on challenges encountered in aerospace, aviation, and aero-engine applications, this paper identifies priority research domains requiring urgent attention and critical technologies demanding breakthroughs in the hybrid structure design, offering valuable insights for researchers in related fields.

This paper proposes a novel high-order asymptotic expansion analysis method for generalized periodic lattice structures, aimed at accurately predicting their physical and mechanical behaviors and equivalent performances. The proposed method converts the homogenization problem of generalized periodic lattice structures into the classical two-scale homogenization problem for a cubic unit cell, thereby elucidating the intrinsic mapping mechanisms of the generalized two-scale homogenization approach. This conversion clarifies the fundamental properties of the equivalent performance of generalized periodic two-scale homogenization, substantially reducing the computational and programming complexities involved. By employing typical numerical examples, this paper compares the outcomes from the proposed mapping method with those derived from classical periodic two-scale homogenization and fine-scale finite element methods. The results affirm the universality and effectiveness of the proposed method, which exhibits high computational precision for addressing both static and dynamic issues, such as natural frequency calculations, thus providing strong theoretical support and practical pathways for designing high-performance, lightweight structures in generalized periodic lattice configurations.

The rapid development of next-generation aerospace vehicles has imposed more stringent requirements on structural components in terms of super-high load-bearing capacity, ultra-high precision, and extreme lightweight design. How to effectively maintain the geometry and functionality of key areas through structural design while ensuring the load-bearing performance under harsh aerospace load environments is a typical shape preserving design problem. Firstly, this paper systematically reviews the research progress related to shape preserving design based on topology optimization method, discussing the origins of the shape preserving concept and its applications in aerospace structural design. Subsequently, the recent applications of shape-preserving concepts in the fields of statics, dynamics, and multi-physics coupling are summarized in depth, clarifying that the core of shape preserving design lies in energy regulation and channeling within the structure. On this basis, the paper further summarizes the practical achievements of shape preserving methods in the optimization design of complex aerospace structures, optical-mechanical systems, and multi-component layouts, emphasizing the significant value of shape preserving ideas in functional system design. Finally, it explores the development and application prospects of shape preserving through energy channeling concepts in fields such as multi-scale structural design, robust optimization, and complex aerospace system design, providing theoretical references and technical support for future related research and equipment development.

By the virtue of its design orientation of “multi-functionality” and efficient repeated flights in large airspace and wide speed range, the cross-domain vehicle is of epoch-making significance in the field of aerospace and is becoming one of the focuses of technological competition among various countries. Due to the high frontier and comprehensive nature of this field, there is no clear technical route to realize the large envelope cross-domain vehicle, but it is generally agreed that the morphing configuration is the key technology and necessary means. In this paper, we discuss the conceptual routes to achieve cross-domain vehicle from four aspects, namely, the basic configuration, the morphing mode, the optimization of the morphing structure, and the thermal protection, with the morphing configuration as the main theme. We analyze the technology pavements and reference values provided by the existing researches on the design of cross-domain vehicle, and summarize the respective technological advances and challenges. Firstly, several basic configurations with application potential are introduced, and the differences in aerodynamic performance and volumetric ratio are compared; secondly, the structural design and aerodynamic impacts of different schemes are analyzed according to the classification of wings and head-cones; then, three levels of structural optimization techniques, passive and active thermal protection structural designs are introduced from the perspective of improving the deformation, load-bearing, and thermal protection performance of the morphing structures; finally, we summarize the challenges and problems that are still facing in the work of cross-domain vehicle structures and morphing configuration design, and look forward to the future development direction of related research.

Lightweight is a substantial theme in the research and development of aerospace and aeronautical equipment due to its decisive impact on the comprehensive performance and operational efficiency of the equipment. Over the past decades, a handful of innovative optimization design approaches, emerging high-performance materials, and revolutionary manufacturing technologies have been uninterruptedly developed, and the level of lightweighting in aerospace and aeronautical equipment has been significantly advanced. However, the increasing demands for comprehensive performance and multifunctionality of the next generation of equipment present serious challenges to existing lightweight design and manufacturing technologies. Therefore, with a particular emphasis on the layout design, electromechanical system design, materials and structures, high-performance manufacturing and assembly, this paper analyzes the posed challenges and future perspectives.

This work is devoted to the aeronautical application of topology optimization for modular structures with multiple assemblies that consist of repeated standard modules and optional reinforcements. These kinds of structures are widely used owing to their transportability, reconfigurability, low manufacturing and service costs. In this work, the design of airborne shelves with modular structures characterized by the standard module configuration is formulated for the first time as a topology optimization problem of multiple assemblies and multiple load cases subjected to the volume constraint. It is shown that the weighted compliance design of multiple assemblies is a compromising solution compared to the optimization result of each individual assembly of standard modules. Meanwhile, the performance of optimized airborne shelves with the modular structures can effectively be ameliorated with the help of reinforcements.

This study focuses on the lightweight design of a specific bypass engine casing, considering the complex effects. A topology optimization approach is first employed to determine the optimal layout of stiffening ribs under various loading conditions. Additionally, taking into account the buckling stability requirements for the casing, the correlation between four common reinforcement configurations and structural buckling resistance is systematically studied. A hierarchical stiffening strategy on the basis of triangle and hexagonal patterns is proposed, and built a parametric model for the periodically stiffened casing. A comprehensive optimization design objective, based on stress levels of stiffening ribs and structural buckling resistance, is finally developed. The optimized reinforcement design for the bypass engine casing achieves a weight reduction of approximately 40% compared to the original design model. Moreover, it surpasses the structural stiffness and strength requirements and exhibits a significant enhancement of 212.9% in the critical buckling load when compared to a structure with a wall thickness of 1.3 mm. These advancements effectively ensure the operational stability of the bypass engine casing under severe load conditions.