To tackle real-time localization and force identification challenges induced by complex stiffness distributions, this study proposes a low-speed impact monitoring method for aerospace composite panels. By integrating distributed fiber optic sensing with physics-informed deep learning, a two-stage strategy simultaneously identifies impact location and force. This study collected dynamic strain responses from 165 impact events using 48 fiber Bragg grating sensors. The framework utilizes a Convolutional Neural Network (CNN) for initial detection and regional classification, which subsequently activates a physics-informed submodel. By embedding linear force-strain priors and geometric constraints, this approach overcomes data scarcity issues common in pure data-driven models. The results validate that this physics-data fusion offers superior robustness and accuracy for aerospace structural health monitoring.

Discrete Ritz method (DRM) is combined with virtual spring technique, first-order shear deformation theory (FSDT), and Newton–Raphson method, for the first time, to analyze the nonlinear bending problem of arbitrarily shaped plates under different geometric boundary conditions. DRM constructs a rectangular domain enclosing the geometric domain of the plate, and then, by using Gauss points in the rectangular domain for discretization associate with variable stiffness properties, the plate geometry is numerically simulated by cutouts within the rectangle. The global displacement field of the plate is approximated by Legendre polynomials based first-order shear deformation theory. The geometric nonlinearity is considered in terms of the von Kármán nonlinear theory. Virtual spring technique is used to simulate spring stiffness coefficient of distinct boundary conditions on complex geometric domain and embedded into the global stiffness matrix. DRM is combined with Newton-Raphson method to solve the nonlinear bending equations of plate with complex geometries. Numerical examples and comparisons with the results in the literature and FEM demonstrate that DRM based on constraint springs can be used to analyze the geometric nonlinearity of arbitrarily shaped plates under different boundary conditions with good feasibility and accuracy.

In recent decades, hydrogen-powered aircraft have emerged as a pivotal solution for decarbonizing aviation. However, their structural crashworthiness is compromised by unique deformation mechanisms, notably the "W"shaped failure mode in the aft fuselage where liquid hydrogen tanks are installed-a risk insufficiently addressed in prior studies. This investigation evaluates the effect of a keel beam design on mitigating these deformations. A finite element model of a regional aircraft with liquid hydrogen tanks in the aft fuselage was developed, simulating a vertical crash at 9.14 m/s. The baseline configuration (without keel beam) exhibited significant bending and a distinct "W"-shaped collapse, severely jeopardizing tank integrity. We hypothesized that keel beam integration would enhance local rigidity and suppress deleterious deformations. Simulations confirmed that the keel beam eliminates the "W"-shaped mode, reduces tank deformation by over 30 %, and maintains passenger acceleration within safe thresholds. These findings provide a novel design strategy for enhancing the crashworthiness of next-generation hydrogen-powered aircraft.

As the demand for amphibious aircraft intensifies, the challenge of water impact has emerged as a critical technical hurdle impeding broader adoption. This research focuses on the water impact protection of amphibious aircraft composite panels (AACP) by designing three distinct AACP configurations with varied stiffness properties through the manipulation of stringer spacing and skin configuration. Employing a custom-designed apparatus and methodology for water impact simulation, this research accurately replicated the cabin's water impact load time-history curves on the AACP surface, achieving a reproduction error within 5 %. The dynamic response and damage characteristics of the AACP under water impact were analyzed using the 3D Hashin failure criterion and a cohesive zone model. The findings reveal that the proposed equivalent bending stiffness ratio (Rx,m) and the stiffness configuration analysis method are effective in evaluating responses such as deformation and strain. The configuration with a four-stringer sandwich skin panel (Rx,m = 1.236) exhibited superior performance, reducing peak deformation and strain by up to 43.2 % and 50 %, respectively, compared to other configurations. In contrast, configurations with a low Rx,m demonstrated inadequate load-bearing capabilities and suffered transverse skin fractures during testing due to stiffness mismatches. Both simulation and experimental results confirm the pivotal role of stiffness distribution in energy absorption and damage modalities. This research provides essential insights for the design of lightweight, impact-resistant composite structures.

The Blended Wing Body (BWB) configuration in civil aviation represents a major leap in aerodynamic performance, achieved through the seamless integration of fuselage and wing structures-effectively breaking through the design constraints of conventional "tube-and-wing" aircraft. Yet, this architectural innovation brings new challenges: the flattened fuselage places cabin doors directly on the windward surface, increasing the risk of cabin depressurization following bird impacts. Current airworthiness regulations (e.g., CCAR-25.365) lack specific provisions regarding bird strike resistance for cabin doors, and thus, traditional protective strategies are not readily transferrable to BWB designs. To address this, a Finite Element (FE) model was constructed for the BWB cabin door, incorporating the Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS). Upon validating its static strength under extreme loading conditions, a surrogate model was established, enabling multi objective optimization using Latin Hypercube Sampling (LHS) and the Non-dominated Sorting Genetic Algorithm II (NSGA-II) algorithm. This optimization yielded a 23.27% mass reduction, with a 10.28% increase in the Tsai-Wu failure factor. Furthermore, a coupled Smoothed Particle Hydrodynamics-Finite Element Method (SPH-FEM) numerical approach was employed to simulate the bird strike scenario involving a 3.6 kg bird traveling at 140 m/s at an incidence angle of 18.43 degrees. To bolster impact resistance, structural enhancements were introduced using 7075-T351 aluminum alloy doublers around the door and adjacent cutouts. These enhancements were further refined via a Multi-island Genetic Algorithm (GA), resulting in an additional 32.20% reduction in reinforcement mass. The post-optimization analysis confirmed the absence of perforation damage and plastic deformation in the door locking system and kinematic linkage. This research establishes a novel framework for assessing bird strike resilience in BWB cabin doors, contributing foundational data to airworthiness certification and offering practical reference for subsequent experimental validations.

Composite aircraft structures inevitably sustain low-velocity blunt-body impacts, resulting in internal damage that is difficult to detect. Existing research primarily focuses on damage analysis of aircraft panel structures under ideal boundary conditions, which do not fully correspond to the actual boundaries of panel structures. This study examines the AC531/CCF800H carbon fiber epoxy resin-based composite skin panel and introduces a design methodology for the elastic support boundary of large curved composite aircraft skin panels. Elastic-support boundary: K H = 435 KN/m, K theta = 280 KN*m/rad reproduces the measured stress error within 10.44% and displacement error within 8.18%. Peak impact force rises linearly with energy (Fpeak = 1.464 E + 52,406 N, R2 = 0.997) and drops 26% when the angle increases from 0 degrees to 40 degrees. This study delivers a predictive tool that directly supports damage-tolerance compliance for future composite fuselages exposed to ground-handling operations.

There are few studies on the pressurization-compression mechanical behavior of the pultruded rod stitched efficient unitstructure (PRSEUS) in blended wing body (BWB) aircraft. Thus,finite-element models of PRSEUS curved panels withvarying curvatures, prefabricated cracks, and repair strategies were developed in this study tofill this gap. The damagemechanisms under pressurization-compression cases were systematically analyzed through an improved Hashin failurecriterion coupled with a damage-evolution scheme. The results demonstrate that curvature changes significantly affectedpanel stiffness and ultimate load capacity. Specifically, under biaxial compression, the frame-direction load capacity de-creased by 23%-27% compared to uniaxial compression; prefabricated cracks reduced ultimate loads by up to 65% and 62%in the frame direction and the stringer direction, respectively; composite repairs effectively restored structural perfor-mance, and titanium-alloy repairs elevated frame-direction ultimate loads by 8.3%-15.2% over unrepaired panels. Thesefindings support the design and damage-repair strategies for PRSEUS structures.

Bird strikes remain one of the major threats to flight safety, particularly during takeoff and landing phases. Despite this, the safety of landing operations following bird strike on the landing gear-an essential load-bearing system during these phases-has not received sufficient research attention. In this study, a finite element (FE) model of a strut-type nose landing gear system for a civil aircraft is developed to simulate both normal and repeated landing processes after a bird strike. The residual strength and fundamental performance of the landing gear structure post-impact are evaluated. Results show that, compared with an unimpacted landing gear system, bird strikes can significantly impair cushioning performance and reduce the safety margin. Under normal landing conditions, damping dissipation efficiency decreases by 9.75%, and the safety margin drops by 19.2% to 34%. For heavy landings, the damping efficiency is reduced by 2.8%, with a safety margin decline ranging from 14% to 38.8%. Based on the identified risks associated with bird strike, a design criterion for impact resistance and a corresponding reinforcement scheme are proposed. The effectiveness of reinforcement patches of varying thicknesses is further evaluated using the analytic hierarchy process (AHP), considering factors such as structural weight increase and safety margin improvement.

Fatigue cracking in L-shaped aerospace components is a major safety concern. Ultrasonic guided waves can monitor this, but the complex geometry causes multimodal conversion and scattering, which creates noise and hides damage signals. We propose a visualization method combining the Adaptive Hybrid Backward Matching Pursuit (AHBMP) algorithm with an enhanced Reconstruction Algorithm for Probabilistic Inspection of Damage (RAPID) framework. We use AHBMP to decouple overlapping signals and isolate the A0 mode, as it is highly sensitive to cracks. This data is then processed by an enhanced RAPID algorithm that introduces a third focal point to refine the probability distribution. This approach significantly betters damage localization and resolution. Experiments show the method tracks the full fatigue lifecycle, from initiation to propagation. In the stable propagation phase, crack length estimation error remained below 5%, proving its practical engineering value.

The Pultruded Rod Stitched Efficient Unitized Structure (PRSEUS) proposed by NASA provides a viable pathway for all-composite aircraft. Nonetheless, its reliance on the traditional [0 degrees/+/- 45 degrees/90 degrees] quad-layer system curtails the overall optimization potential. Traditional design approaches depend heavily on empirical testing and localized reinforcement, complicating optimization efforts and frequently resulting in structural thickening, increased weight, and elevated costs. To address these challenges, this study introduces a novel Double-Double (DD) laminate system to evaluate its feasibility as a replacement for traditional laminates, while conducting synergistic optimization of laminate angle and thickness. This study demonstrates that the DD laminate system not only fulfills the functionality of traditional laminates but also streamlines the optimization process, enhancing mechanical properties while reducing weight. The PRSEUS structure based on the DD laminate holds promise as an optimal solution for next-generation aircraft composite material design, thereby broadening the application prospects of high-performance composites in the aerospace field.

In the pursuit of sustainable development and green aviation, the Blended Wing Body (BWB) configuration has emerged as a focal point in aviation technology innovation, distinguished by its superior aerodynamic characteristics, fuel efficiency, and enhanced passenger capacity. This study systematically reviews the technical progress of both domestic and international civil aircraft projects featuring BWB configurations, with a special emphasis on the NWPU-BWB-300 scheme developed by Northwestern Polytechnical University. The study examines its economic performance and adaptability to airports, revealing that the NWPU-BWB-300 offers advantages in terms of development and manufacturing costs, exhibits superior fuel economy compared to similar models, and aligns well with market competitiveness and eco-friendly aviation trends. Further analysis confirms that this model can integrate seamlessly with existing 4E class airport infrastructure and services, including jet bridges and tanker refueling vehicles, thereby demonstrating robust airport compatibility. These findings not only validate the technical feasibility of the NWPU-BWB-300 scheme but also serve as valuable references for its potential market application.

Bird strikes remain one of the major threats to flight safety, particularly during takeoff and landing phases. Despite this, the safety of landing operations following bird strike on the landing gear—an essential load-bearing system during these phases—has not received sufficient research attention. In this study, a finite element (FE) model of a strut-type nose landing gear system for a civil aircraft is developed to simulate both normal and repeated landing processes after a bird strike. The residual strength and fundamental performance of the landing gear structure post-impact are evaluated. Results show that, compared with an unimpacted landing gear system, bird strikes can significantly impair cushioning performance and reduce the safety margin. Under normal landing conditions, damping dissipation efficiency decreases by 9.75%, and the safety margin drops by 19.2% to 34%. For heavy landings, the damping efficiency is reduced by 2.8%, with a safety margin decline ranging from 14% to 38.8%. Based on the identified risks associated with bird strike, a design criterion for impact resistance and a corresponding reinforcement scheme are proposed. The effectiveness of reinforcement patches of varying thicknesses is further evaluated using the analytic hierarchy process (AHP), considering factors such as structural weight increase and safety margin improvement.

This study focuses on the dynamic response of aircraft tires under hard landing conditions. Through both quasi-static and dynamic compression testing, the mechanical properties of tire rubber at varying strain rates were assessed. Critical mechanical parameters were derived from these results and a finite element simulation was conducted to evaluate the impact of varying sinking speed, loads, and aircraft roll angles on tire sinking displacement and stress distribution. The findings indicate that increases in sinking speed and load significantly raise the peak stress within the tire rubber. At a sinking speed of 6.09 m/s or a load of 12,000 kg, the tire's loadbearing capacity is surpassed, with rubber stress exceeding 30 MPa. Excessive roll angles were found to potentially induce cracks in the sidewall rubber, though the overall threat to the tire's load-bearing capacity remains constrained. This research contributes significantly to the safety analysis of aviation tires under overloaded landing conditions and provides a theoretical foundation for the optimization of tire design.

With the widespread use of composite materials in aircraft structures, the structural safety of these materials under extreme meteorological conditions has become increasingly important. Hail can cause various types of damage to composite structures, such as delamination, fiber fracture, and interfacial debonding, which seriously threaten flight safety. This paper presents a systematic review on the design for hail impact resistance in aerospace composite structures, examining the mechanical characteristics of hail impact and its effects on the response behavior of composites. The study indicates that a suitable layup method, interfacial toughening technology, and core structure design can improve the energy dissipation capacity and damage suppression effectiveness of composite structures under hail impact. Additionally, self-healing composites are shown as a promising method for autonomous damage repair and extended service life. Ultimately, it is recommended that future research should focus on hailstone modeling, multiscale damage evolution mechanisms, and intelligent material design to support the structural safety design of aircraft in extreme climates.

Fiber-reinforced composite panels have become the primary load-bearing structures in aircraft due to their exceptional stiffness, specific strength, and mechanical properties. Owing to the high cost of experimental testing, numerical simulation is considered an effective method for rapidly modeling impact behavior and predicting complex internal failure mechanisms within composites. This study utilizes a combined approach of finite element simulation and experimental research to explore the low-velocity blunt-body impact behavior of composite laminates (CLs). The simulated peak impact force and pulse width demonstrated errors within 5.83% and 4.95% of the experimental results, respectively. This study provides effective support for investigations into the low-velocity blunt-body impact performance of CLs.

Multi-source data fusion stands as a pivotal technology for enhancing aircraft structural health monitoring (SHM) system performance and ensuring flight safety. To systematically outline the research landscape and development trajectories in this domain, this paper first elaborates on the theoretical framework of data fusion, encompassing three fusion modalities—competitive, complementary, and collaborative— alongside a three-tiered fusion architecture that spans data-level, feature-level, and decision-level integration. Subsequently, from an application perspective, research advances in data fusion techniques for critical aircraft structures were reviewed. In metallic structures, fusion methodologies have significantly enhanced the detection accuracy of classical damage modes, such as fatigue cracks. For composite structures, multi-modal fusion— particularly when integrated with deep learning—provides powerful tools for addressing complex failure mechanisms, including delamination and impact damage. At full-aircraft level, digital twin-centered fusion platforms are advancing SHM toward systemic predictive health management paradigms. Finally, this paper synthesizes core challenges hindering operational deployment: data heterogeneity, scarcity of damage samples, and poor model interpretability. Future breakthrough directions, represented by physics-informed intelligent fusion, digital twin-driven holographic perception, and Explainable Artificial Intelligence (XAI), were further projected. Collectively, this work delivers a comprehensive knowledge map and forward-looking perspectives for data fusion research and implementation in aircraft SHM systems.