随着激光武器的快速发展，抗激光加固设计将成为高速飞行器结构设计必须要考虑的一个关键问题。本文从结构/功能一体化设计的角度，提出了一种以填充点阵夹层结构为原型的新概念抗激光加固结构，开展了连续激光防护性能的设计、分析与验证，并对其潜在的工程应用进行了探讨。

本文分别从“单元级”激光防护和“结构级”激光防护两个层面研究了点阵夹层结构抗激光加固机理及其热力破坏行为。单元级激光防护目标是通过合理的防护策略延迟结构背表面出现温度响应时间并延缓材料温度到达熔点的速率；结构级激光防护目标是使发生激光损伤结构保持足够的剩余承载强度。在激光防护研究过程中需要考虑包含高速来流下的激光与材料相互作用、激光对结构的热力破坏等多场耦合效应。本文结合理论分析、数值仿真、实验研究等方法对上述科学问题展开研究。

在单元级激光防护层面，研究了填充点阵夹层板的抗激光加固机理。首先对无填充点阵夹层结构激光防护能力与等厚度单层板进行对比研究，二者防护能力存在临界厚度的竞争机制，在面板较薄条件下无填充点阵夹层结构更具有优势。通过填充功能材料，可以进一步增强点阵夹层结构的激光防护性能。本文提出了以多孔陶瓷材料为代表的“隔热型”填充和以碳粉颗粒增强硅树脂材料为代表的“烧蚀型”填充两种填充增强激光防护策略。通过常规静态环境和高超声速风洞实验研究表明：烧蚀型填充增强夹层结构显著提升了单元级激光防护性能。

对烧蚀型填充增强夹层结构激光防护机理进行进一步研究分析。结合激光烧蚀前后填充材料变化，采用数值仿真方法揭示了烧蚀型填充增强夹层结构与激光相互作用过程。研究表明烧蚀型填充激光防护策略优势来自三个方面：低导热硅树脂基材料及其热解产物的隔热作用；树脂基材料热解反应吸热作用；填充碳粉颗粒和基体热解产物通过相变潜热的吸热作用。其中热解和相变过程是烧蚀型填充策略提高结构抗激光能力的重要原因。

本文选用了飞行器主体结构中常见的圆柱壳结构作为结构级激光防护研究对象。改进了“切割嵌锁-真空钎焊”的加工工艺，设计制备出全金属金字塔型三维点阵夹层圆柱壳结构，推动了点阵夹层结构从简单平板构型向具有实际飞行器应用背景的曲面构型发展。对完好点阵夹层圆柱壳的轴压力学性能进行研究，绘制出不同几何参数下的点阵夹层圆柱壳轴压失效图谱。讨论了硅树脂基填充材料对夹层圆柱承载力的影响。

在结构级激光防护层面，研究了夹层圆柱壳结构在热软化损伤和烧蚀开孔损伤两种激光损伤下结构的缺陷敏感性。通过与等厚度单层圆柱壳对比表明，夹层壳具有以下激光防护优势：通过合理结构设计，提高面板刚度，大尺寸夹层壳结构比等厚度单层壳结构具有更高的轴压承载能力；点阵夹层圆柱壳对局部热软化损伤不敏感；夹层圆柱壳存在外层壳单层开孔的破坏过程，减小了结构在激光辐照下突变性承载力失效的可能性。外层壳单层开孔损伤阶段内层壳无明显破坏，整体结构仍具有一定的剩余承载力。

不论是从单元级热物理-化学激光烧蚀过程分析还是从结构级热力响应分析，点阵夹层结构对连续激光防护都具有明显的优势。多功能一体化点阵夹层结构设计，在未来飞行器连续激光防护领域有很大的应用前景。

With the rapid development of laser weapons, anti-laser reinforcement will become a key problem that must be considered in the structural design of high-speed aircraft. Based on the perspective of structure and multi-function integration design, a new concept of laser-resistant reinforced structure based on filled lattice sandwich structures is proposed in this dissertation.

In this dissertation, laser resistance mechanisms and thermal damage behaviors of lattice sandwich structures are studied in two aspects: "unit-level" laser resistance and "structure-level" laser resistance. The object of unit-level laser resistance is to delay the temperature response time of the back surface and the speed of the temperature rising to the melting point. The goal of structure-level laser resistance is to maintain sufficient residual bearing strength of structures under laser damage. In the research of anti-laser reinforcement, the multi-field coupling effects of laser and material interaction with high-speed airflow and thermal damage of laser to the structure should be considered. This dissertation combines theoretical analysis, numerical simulation and experimental research to study above scientific problems.

Laser resistance mechanisms of filled lattice sandwich plates are studied for the unit level. By comparing the laser resistance capability of hollow lattice sandwich plates with equal-thickness single-layer plates, the competitive mechanism of resistance capability with critical thickness is proposed. The laser resistance performance of lattice sandwich plates can be further enhanced by filling in functional materials. In this dissertation, two kinds of filling strategies are proposed: "insulation" filling strategy represented by porous ceramic material and "ablative" filling strategy represented by toner particle reinforced silicone resin composites. Based on the experimental study in the static environment and hypersonic flow environment, it is found that the ablative filling enhanced sandwich plate significantly improves the performance of laser resistance at the unit level.

The laser resistance mechanisms of ablative filling enhanced sandwich plates are further studied by numerical simulation. The interaction between laser and sandwich structure is revealed by comparing the filling material changes before and after laser ablation. It is found that the advantages of laser resistance of ablative filler materials are in three aspects: the thermal insulation effects of silicon resin materials and their pyrolysis products; the endothermic reaction of pyrolysis process; the endothermic reaction of phase change process of filled carbon powder particles and pyrolysis products. The pyrolysis and phase change processes play important roles in the improvement of laser resistance capability.

The cylindrical shell structure, which is common in the main structure of aircraft, is selecteted as the research objective at the structure-level laser resistance. "Snap-fitting and vacuum brazing" fabrication methods are proposed and an all-metallic sandwich cylinder with pyramidal truss cores is designed in this dissertation. This fabrication technology promotes the development of lattice sandwich structures from simple flat configuration to curved configuration, which is closer to the actual application of aircraft. The axial compression performances of the perfect lattice sandwich cylinder are studied. The influence of silicone resin filling material on the bearing capacity of the sandwich cylinder is also discussed.

For the structure-level laser resistance, the imperfection sensitivity of lattice sandwich cylinder to laser thermal softening damage and ablation hole damage is studied. By compared with the single-layer cylindrical shell with the same thickness, the sandwich shell has following advantages for laser resistance: through reasonable structural design, the panel stiffness can be improved and the large-size sandwich cylinder has a higher bearing capacity; the sandwich cylinder is not sensitive to local thermal softening damage; The failure process of single layer hole damage in the outer shell reducing the possibility of the structure's mutation bearing capacity failure under laser irradiation.

.In this case, the inner shell with no obvious damage still has a certain residual bearing capacity, which reduces the possibility of the failure of the structure's mutation bearing capacity under laser irradiation.

Lattice sandwich structures have better protection against continuous lasers from both the analysis of thermal physical-chemical interaction at the cell level and the analysis of thermal response at the structure level. The multi-function integrated lattice sandwich structure design has a great application prospect in the field of continuous laser protection of future aircraft.