Evolution Of Structural Damage Research Articles

Shaking table test on progressive collapse of the double-layer cylindrical reticulated shell with infilled wall

Double-layer cylindrical reticulated shell has made rapid development in recent decades in China, which is widely used in the large-scale public buildings such as gymnasiums, airplane terminal, Shopping mall, etc. Stability and progressive collapse mechanism have been attracting a lot of attention because the large span space structure is largely affected by the geometry nonlinear, which makes it sensitive to the local damages. The infilled wall has a greater impact on the stiffness of the lower supporting structure due to sparse column grid. However, the influence of infilled walls on the collapse mechanism of large-span spatial structures is very complex due to the coupling of upper and lower structures. Therefore, the effects of infilled walls on double-layer cylindrical reticulated shell was investigated by a series of progressive collapse tests with shaking table. In order to evaluate the seismic performance and the capacity of resisting progressive collapse, the structural dynamic characteristics and response laws were obtained under different ground motions and input principal directions. The results indicated that the existence of infilled wall made the coupling between the lower supporting structure and the upper roof structure more complicated. The infilled walls influenced the structural damage evolution and development, mitigated the damage from the earthquake and changed the progressive collapse pattern, which made the catenary collapse mechanism occur when the structure collapsed. Although the further quantitative study is still needed, this paper provides lots of useful test data and conclusions, which gives references to the infilled wall design and seismic performance evaluation for double-layer cylindrical reticulated shell.

Effects of Ar ion bombardment on the structure and properties of β-quartz

β-quartz is an important component that affects the physical and chemical properties of glass-ceramics. The material removal process of ion beam machining is complicated as one of the ultra-precision machining forms. Therefore, it is important to understand the removal mechanism of ion beam machining materials. The methods of molecular dynamics (MD) and first-principles were adopted to investigate the microscopic mechanism of ion beam bombardment of the β-quartz structure. The damage evolution of structures and the evolution of material properties caused by defects respectively from the atomic and electronic levels. Through MD analysis, we find that the random collision between incident ions and matrix atoms can lead to the formation of sputtered atoms. The incidence of ions will increase the disorder degree of the matrix, and the influence on the disorder degree at different depths of the matrix is different. The degree of disorder increases obviously in the range of 50–70 Å from the surface of the matrix. It has a significant impact on the surface topology of the matrix, the number of defects, surface roughness, and matrix density. The results of first-principle calculation show that the refraction, absorption and other characteristics of the system are significantly different with different doping forms, and the energy loss is most affected by substituted doping. And the substituted doping defects have the most significant effects on the structural energy loss. Among, the Ar-substituted O doping structure leads to higher energy loss, and the peak energy loss intensity reaches 5.146. In contrast, the Ar-substituted Si doping structure causes the least energy loss, the intensity is 2.543. This study provides a theoretical basis for the selection of parameters and the realization of ultra-smooth surface in actual ion beam machining.

State-of-the-Art Research on Loess Microstructure Based on X-ray Computer Tomography

Computer tomography (CT), combined with advanced image processing techniques, can be used to visualize the complex internal structures of living and non-living media in a non-destructive, intuitive, and precise manner in both two and three-dimensional spaces. Beyond its clinical uses, CT has been extensively employed within the field of geotechnical engineering to provide both qualitative and quantitative analyses of the microstructural properties of loess. This technology has been successfully applied in many fields. However, with the rapid development of CT technology and the expansion of its application scope, a reassessment is necessary. In recent years, only a few documents have attempted to organize and review the application cases of CT in the field of loess microstructure research. Therefore, the objectives of this work are as follows: (1) to briefly introduce the development process of CT equipment and the basic principles of CT and image processing; (2) to determine the current state and hotspots of CT technology research based on a bibliometric analysis of the literature from the past three decades in the Web of Science Core Collection and CNKI databases; and (3) to comprehensively review the application of CT to explore the microstructural characteristics (such as particle size, shape, arrangement, and the connectivity, orientation, and pore throats of pores, etc.) and the evolution of structural damage in loess within geotechnical science. In addition, the progress and deficiencies of CT applications in the field of loess microstructure are summarized, and future prospects are proposed.

Multi-GPU parallel acceleration scheme for meshfree peridynamic simulations

Peridynamics (PD) using integral equations has unique advantages in modeling structural damage evolution, but the expensive computational and memory costs associated with the nonlocal nature of PD severely limit its engineering applications. This study presents a CUDA-based multi-GPU parallel scheme for meshfree PD simulation, which is compatible with dual-horizon PD supporting multiscale spatial discretization. Efficient utilization of computing resources across all available GPUs is achieved by rationalizing data structures across multiple GPUs and using the CUDA memory model. Using atomic operations to avoid computational dual-bond forces further improves code performance. The classical Kalthoff-Winkler experiment and compact-tensile fatigue test were first carried out using 3 NVIDIA Tesla T4 GPUs. Two examples showed that the proposed scheme significantly accelerates the PD model and that the acceleration enhances approximately linearly with the number of GPUs. The speedup of the PD interaction force computation reaches up to 560.7x. Compared to double-precision floating-point values, the GPU performs much better in handling single-precision values. Finally, a PD simulation of rail head heat conduction under moving heat sources with nearly 76 million particles was realized, demonstrating the potential of the proposed scheme to support large-scale PD simulations.

A spatial nonlocal Green-Naghdi generalized thermoelasticity model based on bond-based peridynamics: Transient responses of laminated structures subjected to thermal shock

The Green-Naghdi generalized thermoelastic model is firstly extended based on the peridynamics and the thermo-mechanical response of laminated structures under thermal shock is investigated in this paper. Firstly, the GN-II and GN-III models of peridynamics (PD-GN model), which can consider spatial nonlocality and discontinuity of problems, are derived. Then, the characteristics of the PD-GN-II model are studied. To validate the correctness of the method and PD-GN-II model in this work, the results are compared with the results of other investigators and FEM results. In addition, the separate effects of non-locality of different fields on the thermo-mechanical response are discussed. Aiming at the thermal coupling problems of laminated structures subjected to thermal shock, the influence of non-local effect, the types of thermal-bonds (weaken or broken thermal-bonds), arrangement of material, and damage location are investigated. It is concluded that the new spatial nonlocal generalized thermoelastic model can handle discontinuous problems well, and material design has significant influence on the thermo-mechanical response and damage evolution of structures. The PD-GN model established in this work is not only a novel spatial non-local generalized thermoelastic model, but also provides a new way to solve the fracture problems in non-Fourier heat conduction.

Study on time effect and prediction model of shear strength of root-soil complex under dry-wet cycle

Triaxial compression tests were conducted on the alfalfa root-loess complex at different growthperiods obtained through artificial planting. The research focused on analyzing the time variation law of the shear strength index and deformation index of the alfalfa root-loess complex under dry-wet cycles. Additionally, the time effect of the shear strength index of the alfalfa root-loess complex under dry-wet cycles was analyzed and its prediction model was proposed. The results show that the PG-DWC (dry-wet cycle caused by plant water management during plant growth period) causes the peak strength of plain soil to change in a "V" shape with the increase of growth period, and the peak strength of alfalfa root-loess complex is higher than that of plain soil at the same growth period. The deterioration of the peak strength of alfalfa root-loess complex in the same growth period is aggravated with the increase of drying and wetting cycles. Compared with the 0 days growth period, the effective cohesion of alfalfa root-loess complex under different dry-wet cycles maximum increase rate is at the 180 days, which are 33.88%, 46.05%, 30.12% and 216.02%, respectively. When the number of dry-wet cycles is constant, the effective cohesion of the alfalfa root-loess complex overall increases with the growth period. However, it gradually decreases comparedwith the previous growth period, and the minimum increase rate are all at the 180 days. For the same growth period, the effective cohesion of the alfalfa root-loess complex decreases with the increase of the number of dry-wet cycles. This indicates that EC-DWC (the dry-wet cycles caused by extreme natural conditions such as continuous rain) have a detrimental effect on the time effect of the shear strength of the alfalfa root-loess complex. Finally, based on the formula of total deterioration, a prediction model for the shear strength of the alfalfa root-loess complex under dry-wet cycles was proposed, which exhibits high prediction accuracy. The research results provide useful guidance for the understanding of mechanical behavior and structural damage evolution of root-soil composite.

Development of a fully automatic damage simulation framework for quasi-brittle materials

This paper proposes a fully automatic analysis framework for static damage analysis of quasi-brittle materials exploiting adaptive mesh refinement approaches as well as adaptive load stepping techniques. The damage process is modelled using an integral-type nonlocal damage model which alleviates the mesh dependence issue. The scaled boundary finite element method and quadtree meshing algorithm are employed in the adaptive analysis. The quadtree algorithm is simple for adaptively remeshing and the mesh refinement is limited to local regions around the damage zones. The elements of the quadtree mesh are modelled by the scaled boundary finite element method, naturally resolving the hanging nodes encountered by the standard finite elements. Furthermore, the regular element shapes and small number of unique element patterns permit a significant reduction of computational cost on processing the element formulations, and an easy implementation of data transfer between two successive meshes. In the last step, the adaptive meshing strategy is combined with an automatic load stepping scheme to create a fully automatic analysis framework. By means of various numerical examples the performance of the proposed method predicting the damage evolution in structures is analysed in terms of its accuracy and efficiency.

Mechanical and internal structural damage evolution in cold recycled mixture under fatigue loading

Cold recycling technology has the virtue of lower cost, fewer pollutant emissions, and less consumption of raw materials and fossil fuels in pavement maintenance and construction. This study aimed to investigate the evolution of fatigue damage in cold recycled mixtures and provide a theoretical basis for improving the service life of cold recycled pavements with high reclaimed asphalt pavement (RAP) utilization rates, ultimately contributing to energy and resource conservation. To achieve this objective, we conducted a study on the mechanical and internal structural damage evolution of cold recycled mixtures produced using different agents (cement and asphalt emulsion). This was accomplished by combining indirect tensile fatigue testing with X-ray CT scanning techniques. The results indicate that the mechanical response of cold recycled mixtures under fatigue loading is closely related to the evolution of their internal structure during various stages of fatigue. Furthermore, it is found that the type of stabilization agent used in these mixtures has a significant impact on their initial air void content and volume distribution, which ultimately affects both the rate and extent of their mechanical and structural damage evolution. Based on these results, recommendations have been proposed for enhancing the fatigue performance of cold recycled pavement through appropriate mixture design strategies that account for these factors mentioned above.

Full-scale testing of masonry-infilled RC frames retrofitted with cross-laminated timber panels

This paper presents the results from an experimental study on an innovative timber-based seismic retrofit solution for existing reinforced concrete (RC) buildings. The intervention aims at enhancing the overall seismic resistance of RC framed structures with a light, cost-effective, sustainable, and reversible approach, allowing possible integration with energy efficiency upgrades. The retrofit technique relies on cross-laminated timber (CLT) panels mechanically connected through steel fasteners to the RC frame. This strengthening technique is investigated experimentally for the first time in this paper. The study examines two intervention configurations with different degrees of invasiveness: the first (RC-TP) involves replacing the existing masonry infill wall with a CLT panel, whereas the latter (RC-TPext) consists in applying the panel to the outer face of the frame. Both retrofit configurations were assessed experimentally through cyclic quasi-static in-plane tests on full-scale single-storey, single-bay RC frames. The frames were identical in geometry and characterised by poor mechanical material properties and steel reinforcement details, promoting the development of a strong-beam-weak-column mechanism. The experiments comprised tests on four specimens: a non-retrofitted masonry-infilled frame employed as a reference specimen and three frames strengthened with CLT panels as infills or externally connected retrofitting elements. The paper presents construction details of the strengthening interventions, demonstrates a step-by-step application procedure, and summarises the main observations from the tests, illustrating the evolution of structural damage, the ultimate failure mode, and the cyclic hysteretic response of the specimens. The experiments showed promising results, proving that both retrofit configurations improved the seismic behaviour of the RC frames considerably. Specifically, the RC-TP and RC-TPext retrofit interventions increased the lateral strength of the reference frame by approximately 169% and 104%, respectively. At the same time, both configurations prevented the shear collapse of the columns.

Seismic performance and damage evolution of RC frames retrofitted by the novel GESB system: A numerical study

A novel gapped eccentric steel brace (GESB) system was developed to enhance the seismic performance of existing reinforced concrete (RC) frame structures. To thoroughly investigate the mechanism and damage mode of the novel retrofitting system, numerical analysis was conducted on retrofitted frames with various brace eccentricity configurations, using a comprehensive multi-scale finite element model. Six suitable damage indices were defined to carry out the structural damage evolution study during the whole loading process. On this basis, a simplified damage model was developed. The results demonstrated that GESB effectively modified the mechanical mechanism and failure modes of the frames. The brace eccentricity configuration exerted a significant influence on the structural strength, stiffness, and ductility. With regards to both of strength and ductility requirements, an eccentricity range of 0.3 to 0.4 was recommended. The proposed simplified damage model was used to indicate the allowable drift ratios associated to performance levels, which were found to be very variable with various eccentricity configurations. The outcomes are essential and timely for design decision of RC frames retrofitted by GESB.

Evolution of structural damage of solid composite propellants under slow heating and effect on combustion characteristics

Composite propellants are used to fabricate solid motors for space vehicles. The fundamental factor that affects motor safety is the structural damage in the propellant owing to slow heating in an abnormal storage or service environment. Hence, their thermal damage and combustion characteristics should be studied comprehensively. In this study, we investigated the combustion behaviours of hydroxyl-terminated polybutadiene/ammonium perchlorate/aluminium powder (HTPB/AP/Al) and hydroxyl-terminated block copolyether/AP/Al (HTPE/AP/AI) propellants under slow heating conditions. The pore structure was observed using scanning electron microscopy and micro-computerised tomography. Their weight loss behaviour, gaseous products, and pore structure evolution were analysed using thermogravimetric analysis, mass spectrometry, and Fourier-transform infrared spectroscopy. The influence of the pore structure on the combustion behaviour was studied by establishing the relationship between combustion and energy release rates. The weight loss rates of HTPB/AP/Al and HTPE/AP/Al before ignition were 34.5% and 16.1%, respectively. Upon heating, the HTPB binder decomposed to form pore channels, through which the gaseous products produced from the decomposition of AP were released, which increased the structural damage in this propellant. In contrast, upon heating, the HTPE binder liquefied and formed a coating on the AP particles, which slowed the structural damage in this propellant. Moreover, the calculated reaction intensity of HTPB/AP/Al was 4.16 times that of HTPE/AP/Al, indicating that larger pore channels increase the burning surface for combustion.

Study on structural damage evolution of excavated slope subjected to earthquake and rainfall using electrical resistivity measurement

Earthquake and rainfall are two major factors contributing to the slope failures. To examine the evolution of slope structural damage and the failure mechanism during the shaking and rainfall process, a model test of excavated slope subjected to earthquake and rainfall has been performed. The evolution of structural damage within the slope is considered as the changing process of porosity and crack development. The unique relation between of porosity and resistivity of unsaturated soil is utilized to reveal the spatial-temporal variation of slope structural damage by electrical resistivity measurement method. The testing results show that the shaking induced cracks appear on the surface of upper soil layer at the mid-height of slope model, and the structural damage could be both accumulated on the surface and inside the slope under seismic motion. The damaged area provides preference infiltration path for rainwater flow in the following raining process, resulting in the rapid increase of water content of slope interior. The sliding body extends and develops upwards to the slope crest under rainfall condition. The failure patten suggested by the structural damage parameter is verified by the dynamic response of slope model. The structural damage parameter using resistivity is able to show the spatial-temporal evolution of structural damage inside the slope quantitatively, and reflect the porosity change of soil under continuous earthquake and rainfall conditions. The evolution of structural damage reveals that the dynamic failure mode of excavated slope under earthquake and rainfall is the upwards-developed retrogressive sliding of upper soil layer. The evaluating method using resistivity measurement is particularly promising for field test of slope where it can be used to monitor the structural damage change of soil mass subjected to complex environment conditions.

Structural Damage Evolution of Mesoscale Representative Elementary Areas of Mudstones

The mechanical behavior of mudstones is significantly affected by their mesostructure. This study investigates the damage evolution of red mudstone mesostructures under uniaxial compression through U-Net image segmentation, mesoscopic representative elementary area (mREA), meso-element equivalent method, and linearly superimposed model. Results show that the mREAs can be simplified as a binary structure comprising nonclayey minerals and a porous matrix. The inclusion-matrix interfaces constituted by the dominant inclusions, such as large inclusions and a series of inclusions with specific arrangements, are the weakest regions at the postpeak stage. The shear failure of these interfaces leads to general shear failure with a penetrating principal fracture or local shear with several nonpenetrating local fractures in the mREAs. The damage evolution and failure mode are sensitive to the inclusion geometric features, e.g., inclination, grain size, and spacing. However, the uniaxial compressive strength (UCS) is mainly determined by the included angle between the dominant inclusion inclination and the loading direction. With consistent composition, an increase in the included angle from 0 to 90° results in an increase in the UCS of the muddy facies and a decrease in the sandy facies, with the UCS of the sandy facies being more sensitive to changes in the included angle. Our findings indicate that the structural failure of red mudstones from mesoscopic to macroscopic is driven by the accumulation and expansion of shear failure at multiple scales due to the presence of hard–soft interfaces. This study enhances our understanding of the structural failure mechanism of mudstones and serves as a practical reference for the mesomechanical testing of clay rocks.

Laboratory test study on moisture migration and structural damage evolution of frozen unsaturated red clay

ABSTRACT Heat transfer, moisture migration and water-ice phase change during the soil freezing process are important factors contributing to frost heave damage in geotechnical engineering. Firstly, the temperature variation characteristics of the samples were obtained using a temperature detection switch (TDS) acquisition system. Secondly, the NMR signal amplitude of the samples after one-dimensional unidirectional freezing under different initial conditions was measured using the GR-HSE sequence. Finally, the evolution of pore development and crack propagation in the samples before and after freezing was characterised using CT scanning technology. The results showed that there was no significant difference in temperature gradient between different regions of the samples, and the freezing depth increased with decreasing temperature. The redistribution characteristics of moisture in the samples after freezing were obtained through its correspondence with moisture content, which confirmed the phenomenon of moisture migration in frozen soil. The porosity of the samples significantly increased after freezing, and the damage in the laminar structure zone was more severe than that in the fibrous structure zone. There were significant differences in the quantity and volume contribution of pores at different particle sizes, and the proportion of pores with higher coordination number increased, promoting the degree of frost heave damage.

Seismic performance and material-level damage evolution of retrofitted RC framed structures by high-performance AVED under different shear-span ratio

To upgrade the seismic performance of reinforced concrete framed structures with insufficient seismic capability, the high-performance acrylate viscoelastic dampers (AVED) are developed. A series of dynamic mechanical performance tests are carried out on high-performance AVED. A new strategy for retrofitting RC framed structures using AVED is proposed. To systematically study this new retrofitting structural system, the seismic performance of seven RC frame specimens and seven AVED-added RC frame specimens with different shear-span ratios of 2.0–8.0 are compared. On this basis, the influence rule of shear-span ratio on structural damage evolution is qualitatively analyzed. The structural damage evolution at material-level under different shear-span ratios is qualitatively comparted and analyzed in the whole process. The research results show that the self-developed AVED has excellent energy-consumption capability, and dynamic mechanical properties and energy-consumption capability are strongly dependent on frequency and displacement amplitude. The added AVED greatly improves the seismic performance of the retrofitted RC frame structure. At the same time, AVED effectively improves the failure mode of the structure and avoids the brittle failure mode of the beam-column joints under low shear-span ratios.

Thermal Spike Responses and Structure Evolutions in Lithium Niobate on Insulator (LNOI) under Swift Ion Irradiation

Irradiating solid materials with energetic ions are extensively used to explore the evolution of structural damage and specific properties in structural and functional materials under natural and artificial radiation environments. Lithium niobate on insulator (LNOI) technology is revolutionizing the lithium niobate industry and has been widely applied in various fields of photonics, electronics, optoelectronics, etc. Based on 30 MeV 35Cl and 40Ar ion irradiation, thermal spike responses and microstructure evolution of LNOI under the action of extreme electronic energy loss are discussed in detail. Combining experimental transmission electron microscopy characterizations with numerical calculations of the inelastic thermal spike model, discontinuous and continuous tracks with a lattice disorder structure in the crystalline LiNbO3 layer and recrystallization in the amorphous SiO2 layer are confirmed, and the ionization process via energetic ion irradiation is demonstrated to inherently connect energy exchange and temperature evolution processes in the electron and lattice subsystems of LNOI. According to Rutherford backscattering/channeling spectrometry and the direct impact model, the calculated track damage cross–section is further verified, coinciding with the experimental observations, and the LiNbO3 layer with a thickness of several hundred nanometers presents track damage behavior similar to that of bulk LiNbO3. Systematic research into the damage responses of LNOI is conducive to better understanding and predicting radiation effects in multilayer thin film materials under extreme radiation environments, as well as to designing novel multifunctional devices.

Value of information from vibration-based structural health monitoring extracted via Bayesian model updating

Quantifying the value of the information extracted from a structural health monitoring (SHM) system is an important step towards convincing decision makers to implement these systems. We quantify this value by adaptation of the Bayesian decision analysis framework. In contrast to previous works, we model in detail the entire process of data generation to processing, model updating and reliability calculation, and investigate it on a deteriorating bridge system. The framework assumes that dynamic response data are obtained in a sequential fashion from deployed accelerometers, subsequently processed by an output-only operational modal analysis scheme for identifying the system’s modal characteristics. We employ a classical Bayesian model updating methodology to sequentially learn the deterioration and estimate the structural damage evolution over time. This leads to sequential updating of the structural reliability, which constitutes the basis for a preposterior Bayesian decision analysis. Alternative actions are defined and a heuristic-based approach is employed for the life-cycle optimization. By solving the preposterior Bayesian decision analysis, one is able to quantify the benefit of the availability of long-term SHM vibrational data. Numerical investigations show that this framework can provide quantitative measures on the optimality of an SHM system in a specific decision context.

A Novel Method for Estimating Acoustic Emission b Value Using Improved Magnitudes

The acoustic emission (AE) b value plays an important role in studying structural damage evolution and disaster precursors. The b value can be obtained from the least square fit between AE event number and magnitude (the Gutenberg-Richter relationship), where the magnitude is generally calculated through the maximum amplitude of an AE signal. However, the magnitudes obtained from amplitudes of different AE signals may be quite different, due to the influence of coupling state between the sensor and specimen (expressed as the sensor sensitivity coefficient, Sc). Thus, the b values obtained from a single sensor and without magnitude correction may not be reliable. To address this, this study used pencil-lead breaks and far-field theory to obtain Sc values. One Sc value may be as much as double another, demonstrating that signal maximum magnitudes should be corrected before b value estimation. The Sc -corrected median magnitude is then treated as the AE event magnitude and used to estimate the b value. Application to uniaxial compression AE data from a red sandstone indicates that the improved magnitude reduces the instability compared to magnitude based on a single sensor. The b value time series among sensors exhibit large differences, while the improved b values agree well with AE event locations and rock specimen failure mode. This research demonstrates for the first time the necessity of amplitude correction in AE magnitude and b value computation.

Modeling of Structural Damage Evolution in Dispersion-Filled Elastomeric Nanocomposites with Regard for Interfacial Interaction

Computer modeling of internal damage evolution in elastomeric nanocomposites with high structural phase inhomogeneity (hard dispersed filler and soft elastomeric matrix) has been carried out. The concentration of filler particles was chosen to be sufficiently high, so that their mutual interaction affected significantly the strength properties of the material. Dispersed inclusions were assumed to be absolutely rigid and durable. Only a finitely deform able incompressible matrix (the mechanical properties of which were set using the neo-Hookean elastic potential) could be damaged. The model takes into account the following specific features of the composite structure: a high stress concentration in the gaps between closely located inclusions, the presence of elastomeric layers with increased stiffness on the surface of filler particles, different interphase contact conditions (full adhesion or slip at the matrix–inclusion interface), and the possibility of anisotropic hardening during uniaxial stretching (due to the reorientation of molecular chains in the elongation direction). The latter factor made it possible to study theoretically the mechanism of formation of high-strength microstrands in the gaps between adjacent particles. The occurrence of such formations in filled elastomers, which was observed in numerous experiments, is a proven fact. A new (anisotropic) fracture criterion has been developed to describe it, because this phenomenon cannot be simulated within the generally accepted strength criteria. The calculations based on this new approach showed that local matrix discontinuities occur not in the gaps between particles (sites of highest stress concentration) but at a certain distance, forming a hollow ring (microstrand) around it. The link between neighboring inclusions is not violated, and the material retains its load-carrying capacity at the macrolevel. Thus, the presence of microstrands is a possible reason for hardening an elastomer when a hard dispersed filler is introduced into it.

Real-time detection of damage evolution using electrohydrodynamic printing

The Non-destructive testing methods are important for the detection of material degradation in aerospace structures. However, it is difficult to monitor structural damages caused by aerodynamic loads, shocks and fatigue during the flight of the aircraft in real time. Therefore, conventional non-destructive inspections are usually performed at periodic maintenance checks. This paper proposes a development of a new sensing mechanism for the real-time monitoring of microscopic damage based on electrohydrodynamic (EHD) technology. Piezoelectric grid sensors were made with Ag inks and PZT/PVDF inks. The piezoelectric effect was used to observe and estimate changes in structures. The sensor formed a layered grid structure by printing uniform piezoelectric lines in the horizontal and vertical directions. The manufactured grid sensor can detect the damages of the structure through changes in resistance, and the damaged vicinity was estimated using the intersections of the resistance changes of piezoelectric lines. The proposed mechanism was found to be a powerful methodology for real-time monitoring the microscopic damages and damage evolution of structures.