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Improved Wavelet-based Spatial Filter of Damage Imaging Method on composite structures

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Chinese Journal of Aeronautics 2011年第5期24卷 665-672页

作者： WANG Yu YUAN Shenfang QIU Lei College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China School of Information and Science Nanjing Audit University Nanjing 210029 China

Piezoelectric sensor array-based spatial filter technology is a new promising method presented in research area of structural health monitoring （SHM） in the recent years. To apply this method to composite structures and give the actual position of damage, this paper proposes a spatial filter-based damage imaging method improved by complex Shannon wavelet transform. The basic principle of spatial filter is analyzed first. Then, this paper proposes a method of using complex Shannon wavelet transform to construct analytic signals of time domain signals of PZT sensors array. The analytic signals are synthesized depending on the principle of the spatial filter to give a damage imaging in the form of angle-time. A method of converting the damage imaging to the form of angle-distance is discussed. Finally, an aircraft composite oil tank is adopted to validate the damage imaging method. The validating results show that this method can recognize angle and distance of damage successfully.

关键词： structural health monitoring composite structures piezoelectric sensors array spatial filter complex Shannon wavelet transform digital signal processing

Repair tolerance assessment for aircraft composite structures using Bayesian updating

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Chinese Journal of Aeronautics 2024年第6期37卷 360-391页

作者： Xin LI Hongfu ZUO Bin YANG School of Automotive and Rail Transit Nanjing Institute of TechnologyNanjing 211167China Civil Aviation Key Laboratory of Aircraft Health Monitoring and Intelligent Maintenance College of Civil AviationNanjing University of Aeronautics and AstronauticsNanjing 211106China

Detection and repair of composite damage is crucial to ensure the safety and reliability of aircraft structures.A novel approach to quantitatively evaluate the repair tolerance of composite structures in civil aircraft based on Bayesian updating is *** method incorporates historical damage inspection data to determine the prior distribution of damage size,which is then updated with newly collected damage size data using Bayesian *** Carlo simulation is employed to investigate the probability of failure and estimate maintenance costs,considering various factors such as the frequency and timing of damage events,damage detection,structural strength,gust loads,and maintenance expenses throughout the lifecycle of composite *** and economic factors are considered to establish a lower threshold for repairs and an upper threshold for maintenance based on the occurrence of accidental impact *** of the effectiveness and feasibility of a quantitative assessment method for repair tolerance is conducted using damage statistics data from civil aircraft routes utilizing the structural skin panels of composite outer *** results demonstrate that the method proposed in conjunction with extensive simulations and full utilization of field damage inspection data can effectively simulate unexpected impact damage situations that may occur during civil aircraft service and evaluate the reliability and economic feasibility of the repair of *** research findings hold significant theoretical and practical value for the preparation of documents for continued airworthiness of composite structures,including structural repair manuals and maintenance programs.

关键词： composite structures Repair tolerance Maintenance Bayesian updating Probability of failure

Reliability design optimization of composite structures based on PSO together with FEA

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Chinese Journal of Aeronautics 2013年第2期26卷 343-349页

作者： Chen Jianqiao Tang Yuanfu Ge Rui An Qunli Guo Xiwei Department of Mechanics Huazhong University of Science and Technology Research and Development Center Wuhan Iron and Steel (Group) Corp.

The present work aims to develop a method for reliability-based optimum design of composite structures. A procedure combining particle swarm optimization （PSO） and finite element analysis （FEA） has been proposed. Numerical examples for the reliability design optimization （RDO） of a laminate and a composite cylindrical shell are worked out to demonstrate the effectiveness of the method. Then a design for composite pressure vessels is studied. The advantages and necessity of RDO over the conventional equi-strength design are addressed. Examples show that the proposed method has good stability and is efficient in dealing with the probabilistic optimal design of composite structures. It may serve as an effective tool to optimize other complicated structures with uncertainties.

关键词： composite structures FEA PSO Reliability analysis Reliability design optimization

A Review of Structural Health Monitoring Techniques as Applied to composite structures

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Structural Durability & Health Monitoring 2017年第2期11卷 91-147页

作者： Amafabia,Daerefa-a Mitsheal Montalvao,Diogo David-West,Opukuro Haritos,George Division of Automotive Mechanical and Mechatronics EngineeringSchool of Engineering and TechnologyUniversity of HertfordshireHatfield AL109ABUnited Kingdom Department of Design and Engineering Faculty of Science and TechnologyBournemouth UniversityPoole BH125BBDorsetUnited Kingdom

Structural Health Monitoring(SHM)is the process of collecting,interpreting and analysing data from structures in order to determine its health status and the remaining life *** materials have been extensively use in recent years in several industries with the aim at reducing the total weight of structures while improving their mechanical ***,composite materials are prone to develop damage when subjected to low to medium impacts(i.e.1-10 m/s and 11-30 m/s respectively).Hence,the need to use SHM techniques to detect damage at the incipient initiation in composite materials is of high *** the availability of several SHM methods for the damage identification in composite structures,no single technique has proven suitable for all *** must be noted that the amount of techniques available nowadays is too extensive to be comprehensively reviewed in a single ***,the focus will be on techniques that can serve as a starting point for studies focusing on damage detection,localisation,assessment and prognosis on certain kinds of ***,the line of thought behind the search and the structure of this review is a result of objectives beyond the scope of the paper ***,it was considered that,once the above was understood,an updated synopsis such as this could also be useful for other researchers in the same field.

关键词： SHM composite structures damage identification failure mechanisms low impact techniques

On the Impact of Manufacturing Uncertainty in Structural Health Monitoring of composite structures: A Signal to Noise Weighted Neural Network Process

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Open Journal of composite Materials 2016年第1期6卷 28-39页

作者： Hessamodin Teimouri Abbas S. Milani Rudolf Seethaler Amir Heidarzadeh School of Engineering University of British Columbia Kelowna Canada Department of Aerospace Engineering Sharif University of Technology Tehran Iran

This article investigates the potential impact of manufacturing uncertainty in composite structures here in the form of thickness variation in laminate plies, on the robustness of commonly used Artificial Neural Networks (ANN) in Structural Health Monitoring (SHM). Namely, the robustness of an ANN SHM system is assessed through an airfoil case study based on the sensitivity of delamination location and size predictions, when the ANN is imposed to noisy input. In light of the observed poor performance of the original network, even when its architecture was carefully optimized, it had been proposed to weigh the input layer of the ANN by a set of signal-to-noise (SN) ratios and then trained the network. Both damage location and size predictions of the latter SHM approach were increased to above 90%. Practical aspects of the proposed robust SN-ANN SHM have also been discussed.

关键词： composite structures Manufacturing Uncertainties Structural Health Monitoring Artificial Neural Networks Signal-to-Noise Weighting

DIRECT ANALYSIS OF STEEL AND composite structures CONSIDERING THE EFFECTS OF FIRE

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DIRECT ANALYSIS OF STEEL AND COMPOSITE STRUCTURES CONSIDERIN...

Hybrid flexural components： Testing pre-stressed steel and GIFRP bars together as reinforcement for flexural members

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作者： J Y Richard Liew H X Yu Rune Natten Kleivel Department of Civil Engineering National University of Singapore

In the last decades,computers have been widely used in the investigation of structural behaviour and *** revolution of computing speed sees an increased reliance of direct analysis for designing large-scale structural *** Paper reviews some of the principles related to the use of direct analysis for performance based design of steel and composite frames and discusses the issues that are essential for implementation in *** examples are given to show the benefits of using direct analysis for evaluating the overall performance of structural systems in terms of serviceability,ultimate strength under accidental design situations such as fire.

关键词： Direct analysis composite structures fire analysis performance-based design

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Frontiers of Structural and Civil Engineering 2018年第3期12卷 352-360页

作者： Mohammed FARUQI Oved I. MATA Francisco AGUINIGA Department of Civil and Architectural Engineering Texas A&M University Kingsville TX 77843 USA

Concrete members historically have used either pre-stressed steel or steel bars. In recent years there has been an increased interest in the use of fiber reinforced polymer （FRP） materials. However, the flexure behavior of a hybrid system reinforced by the combination of pre-stressed steel and glass fiber reinforced （GFRP） is still relatively unknown. The purpose of this work is to study this. Two slabs of 100 and 150-millimeter thickness, with a span of 2.1 m reinforced with both pre-stressing steel and GFRP were constructed and tested to failure using ACI 318-11 and ACI 440.1 R-15. The concrete had strength of 31 MPa and the slabs were respectively reinforced with 5#4 bars and 3#5 bars. Each slab had 37.41 mm2 prestressing wire with a failure stress of 1722.5 MPa. The experimental flexural strength and deflection of slabs were compared with their respective sizes theoretical slabs. The theoretical slabs were either reinforced with pre-stressed steel or GFRP rebars, or a hybrid system. It was found that the hybrid system produces better results.

关键词： Partial pre-stressing composite structures GFRP bars

Design of Multi-layered Protection Against Guided Mortar Threats Yhrough Numerical Modeling

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Defence Technology（防务技术） 2023年第11期29卷 55-65页

作者： Bonny Thawani Seng Kiat Lim Laura Brown Richard Critchley Rachael Hazael Cranfield Forensic Institute Cranfield UniversityDefence Academy of the United KingdomShrivenhamSN68LAUK

The trade—off between protection and weight is a constant consideration when designing a portable protective *** mobility is a desirable attribute and protection must therefore adapt,prompting a demand for lightweight,simple to construct,low-cost and effective ballistic protection *** strength and ductility,wave spreading capability and good energy absorption are key properties for ballistic *** materials,polycarbonate,Kevlar?-epoxy,polyurethane foam,and aluminium alloy,possess these properties and were selected for analysis by numerical *** configurations were proven to be an optimal solution,by exploiting the advantages of each material without having large penalties of mass and *** modelling using ANSYS AUTODYN?is used to simulate monolithic and multi-layered target configurations,to obtain the penetration mitigation *** results are analysed to select configurations based on different requirements,such as lowest cost,lowest mass,best performance,and optimal configuration which balanced the three key parameters *** optimal configuration of Aluminium,Kevlar-Epoxy,Polyurethane,and Polycarbonate has layers with thickness of 7,3,38,2 mm respectively with a total mass of 7.97 kg,total cost of$39.86 and penetration of 29.34%(14.67 mm).Polynomial relationships between performance and mass/cost are also determined.

关键词： Hydrocode Fragmentation High velocity composite structures Foams

A hybrid tubular standing support for underground mines:Compressive behaviour

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International Journal of Mining Science and Technology 2021年第2期31卷 215-224页

作者： Hongchao Zhao Ting Ren Alex Remennikov School of Civil Mining and Environmental EngineeringFaculty of Engineering and Information SciencesUniversity of WollongongNSW 2522Australia 2 School of Geology and Mining EngineeringXinjiang UniversityUrumqi 830000China

This paper presents the development of an innovative standing support for underground *** main feature of this standing support is its exterior container,a combination of polyvinyl chloride(PVC)with large rupture strain and fibre-reinforced polymer(FRP)with high strength-to-weight *** demonstrate the advantages of this cementitious grout filled PVC-FRP tubular(PFT)standing support,a series of compression tests were *** variables included the strength of cementitious grout infill material and the thickness of FRP *** tests were also conducted on cementitious grout-filled PVC tubular(PT)support and cementitious grout-filled FRP tubular(FT)*** tests showed that PFT support presents a typical strain-hardening behaviour together with an outstanding axial deformation ability(>20%of the overall height of the support).In addition,the maximum compressive strength of PFT support is much higher than that of the corresponding PT support and FT ***,using thicker FRP jacket or high strength cementitious grout material can enhance the load carrying capacity of PFT *** comparative results indicated that the high performance of PFT support is mainly attributed to the combination of confining constituents(*** and FRP)and infill material.

关键词： Standing support FRP PVC Confinement composite structures Underground mines