Publications
401 results found
Yue N, Khodaei ZS, Aliabadi MH, 2018, A repairable installation procedure for SHM sensors onto composite structures
A novel procedure for installation of PZT sensors on composites is developed. The procedure is shown, through extensive tests, to be reliable, repeatable and repairable. The integrity of the bonded sensors are assessed following the RTCA DO-160 Environmental conditions and test procedures for airborne equipment. The developed bonding film has been tested on both thermoset and thermoplastic coupons and compared co-cured and secondary bonded sensors with epoxy.
Lambinet F, Khodaei ZS, Aliabadi MH, 2018, Effectiveness of RAPID and SSM algorithms on composite scarf repair, Pages: 535-540, ISSN: 1013-9826
This work focuses on diagnostic methodologies for composite repair patch based on structural health monitoring (SHM) technology. Methodologies based on ultrasonic guided waves (GW) are developed and assessed for monitoring composite scarf repair with piezoelectric transducers. The effectiveness of the RAPID (reconstruction algorithm for probabilistic inspection of defects) algorithm was investigated for adhesively bonded composite patch repair. A composite scarf repair has been weakened by 4-point bending fatigue test and impacted after to generate a Barely Visible Damage (BVID). Both conventional RAPID technique, which requires baseline signals, and the Scaling Subtraction Method (SSM) were applied to detect damage in the bondline. The conventional method showed good performance for defect detection and localization whereas the SSM gives encouraging results for non-linear baseline-free RAPID.
Seno AH, Khodaei ZS, Aliabadi MHF, 2018, An effective impact detection method for composite curved panel, Pages: 529-534, ISSN: 1013-9826
ANNs are only accurate for the scope of the given training data which is not suitable for real life impact localisation due to the large range of possible impact variation. Impact data was collected for a variation of impact cases (angle, mass and energy) on a sensorized curved composite panel. From observation of the obtained data, a robust signal Time of Arrival (TOA) extraction method is proposed using a Normalised Smooth Envelope Threshold (NSET) which is a modification of the currently known Normalised Threshold (NT) method. Two ANNs were trained using TOA extracted with the NT and NSET method from a baseline case and tested with TOA extracted from cases having added variation of impact condition. The results show that the proposed NSET method results in more accurate results for impact cases different to the training case and thus allows for only a single impact training case to accurately predict cases with multiple variation. This enhances the applicability of ANNs for impact localisation in real life conditions.
Salmanpour M, Sharif Khodaei Z, Aliabadi MH, 2018, Damage detection with ultrasonic guided wave under operational conditions
Typical airliners operate in a range of conditions, hence airborne structural health monitoring (SHM) components, must withstand the relevant environmental conditions. Additional to the integrity of the components, the SHM performance (diagnosis and prognosis) must be robust and reliable under environmental and vibration profiles during operation. This work investigates the influence of the operational condition (including temperature, humidity and vibration loads) on the integrity of a piezoelectric based SHM system in terms of integrity of the system and robustness of the diagnosis for detecting barely visible impact damage (BVID) on a CFRP panel. Consequently, compensation techniques are proposed to remove the effect of the environmental loading on the decision-making algorithm. The validity of the proposed algorithm is demonstrated on a composite plate for the operational profile defined in MIL-STD 180G standard for airborne components of a regional aircraft.
Khodaei ZS, Aliabadi MHF, 2018, Damage detection and characterization with piezoelectric transducers: Active sensing, Computational and Experimental Methods in Structures, Pages: 1-46
This chapter presents an overview of prominent structural health monitoring (SHM) techniques for damage detection and localization utilizing ultrasonic guided waves (UGWs). The basic principles of SHM described include the application of permanently fixed sensors on the structure combined with the necessity of minimum manual intervention to monitor the structural integrity. The techniques used in SHM, especially tomography and delay-And-sum (DAS) approach, are described in detail. Particular attention is paid to the development of advanced technical capabilities for making the integration of sensors in modern composite structures practical and efficient so as to facilitate industrialization and certification. Therefore, key aspects that have been included are optimization of sensor positioning and influence of changes in environmental conditions on damage detection algorithms. The theoretical descriptions are combined with several benchmark examples involving finite element analysis and experimental measurements. Finally, application to a curved fuselage composite panel with frames and stringers is presented to demonstrate how a multilevel approach could be used to efficiently detect damage in complex structures.
Li J, Khodaei ZS, Aliabadi MH, 2018, A boundary element model for structural health monitoring based on the S0 lamb wave mode, Pages: 625-631, ISSN: 1013-9826
The aim of this paper was to carry out numerical simulations of structural health monitoring applications for plate structures using the boundary element method (BEM). The fundamental symmetric Lamb mode (S0) is chosen for the SHM applications. The propagation, reflection and diffraction of the S0 mode Lamb wave are modelled using a boundary element formulation based on the plane stress theory. Piezoelectric (PZT) actuators are mounted on plate surfaces to excite the S0 mode wave. A semi-analytical method is adopted to couple the PZT actuators and the host plate. Numerical results show that BEM is a very efficient simulation method for the structural health monitoring of plates.
Yue N, Khodaei ZS, Aliabadi MH, 2018, An innovative secondary bonding of sensors to composite structures for SHM application, Pages: 516-522, ISSN: 1013-9826
A novel procedure for installation of PZT sensors on composites is developed. The procedure is shown, through extensive tests, to be reliable, repeatable and repairable. The integrity of the bonded sensors are assessed following the RTCA DO-160 Environmental conditions and test procedures for airborne equipment. The developed bonding film has been tested on both thermoset and thermoplastic coupons and compared co-cured and secondary bonded sensors with epoxy.
Zou F, Aliabadi MH, 2018, On modelling three-dimensional elastodynamic wave propagation with boundary spectral element method, EUROPEAN JOURNAL OF COMPUTATIONAL MECHANICS, Vol: 27, Pages: 204-228, ISSN: 1779-7179
Sharif Khodaei Z, De Luca A, Caputo F, et al., 2017, Damage characterization of composite plates under low velocity impact using ultrasonic guided waves, Composites Part B: Engineering, Vol: 138, Pages: 168-180, ISSN: 1359-8368
In this work, two numerical procedures based on Finite Elements Method (FEM) have been developed in order to simulate the Lamb wave propagation in Low Velocity Impact (LVI) damaged CFRP (Carbon Fibre Reinforced Polymer) laminate. The former (softening representation), usually adopted in literature, consists of modelling LVI damages by lowering the elastic material properties which allowed investigating the Lamb wave propagation at different stages of LVI damages evolution. The latter, proposed in this paper, conversely to the first one and the most of techniques presented in literature, consists of simulating Lamb wave propagation in a plate characterized by an initial stress-strain state and the related failures carried out by a previous impact simulation involving the same model. Such technique allows a better damage modelling and, consequently, overcoming the damage modelling approximations introduced by the former strategy; the lowering of the elastic material properties leads to a bad damage modelling which does not allow reproducing accurately what happens in the reality. Such procedure allowed investigating the Lamb wave propagation at different impact energy levels.The interaction between Lamb waves and damages has been investigated under three central frequencies of the actuation signal: 150 kHz, 200 kHz and 250 kHz which resulted in interesting observations to minimize the effect of the first lamina's fibres orientation on the wave propagation velocity. It is well known that different wave propagation velocities along fibres and matrix lead to different RMSD (Root Mean Square Deviation) damage index values, even if the sensors are mounted at the same distance from the damage location, resulting in wrong or less accurate information about the identification of both damage size and location during the post-processing phase. Moreover, the relationships between the RMSD damage index values, recorded at different instants of time of the impact history, and the
Li J, Khodaei ZS, Aliabadi MH, 2017, Spectral BEM for the Analysis of Wave Propagation and Fracture Mechanics, Journal of Multiscale Modeling, Vol: 8, ISSN: 1756-9737
This paper presents a spectral boundary element formulation for analysis of structures subjectedto dynamic loading. Two types of spectral elements based on Lobatto polynomials and Legendrepolynomials are used. Two-dimensional analyses of elastic wave propagation in solids with andwithout cracks are carried out in the Laplace frequency domain with both conventional BEMand the spectral BEM. By imposing the requirement of the same level of accuracy, it was foundthat the use of spectral elements, compared with conventional quadratic elements, reduced thetotal number of nodes required for modeling high-frequency wave propagation. Benchmarkexamples included a simple one-dimensional bar for which analytical solution is available and amore complex crack problem where stress intensity factors were evaluated. Special crack tipelements are developed for the ¯rst time for the spectral elements to accurately model the cracktip ¯elds. Although more integration points were used for the integrals associated with spectralelements than the conventional quadratic elements, shorter computation times were achievedthrough the application of the spectral BEM. This indicates that the spectral BEM is a moree±cient method for the numerical modeling of structural health monitoring (SHM) processes, inwhich high-frequency waves are commonly used to detect damage, such as cracks, in structures.
Zou F, Rao J, Aliabadi MH, 2017, Highly accurate online characterisation of cracks in plate-like structures, NDT and E International, Vol: 94, Pages: 1-12, ISSN: 0963-8695
In this paper, an in situ technique for the localisation and the sizing of cracks in plate-like structures is presented. The excitation and the reception of the ultrasonic diagnostic signal – Lamb waves – are achieved by permanently installed piezoelectric ceramic disks. The technique simplifies the underdetermined problem of the full characterisation of cracks to an over-determined problem of the localisation of crack tips. Also, it overcomes the difficulties associated with using the pitch-catch excitation scheme for crack characterisation. The development of the technique was done systematically using analytic models and the finite element method. The technique has been validated by an experiment and assessed by extensive parametric studies. While it was designed to be a convenient approach, highly accurate crack characterisation has been attained as evident through the results of both numerical studies and physical experiments.
Huang T, Yang JJ, Jin J, et al., 2017, Evaluation of stress intensity factors and T-stress by finite block method: Static and dynamic, Theoretical and Applied Fracture Mechanics, Vol: 93, Pages: 222-232, ISSN: 0167-8442
In this paper, the Finite Block Method (FBM) for computing the Stress Intensity Factors (SIFs) and the T-stress under static load and transient dynamic load is presented. Based on the one-dimensional first order partial differential matrices derived from the Lagrange series interpolation, the higher order partial differential matrices can be determined directly. By using the mapping technique, a block with arbitrary shape of the boundary is transformed in the polar coordinate into the normalised coordinate . In order to capture the stress intensity factor and the T-stress, the Williams' series of stress function is introduced in the circular core, centred at the crack tip, with the consideration of traction and displacement continuities along the circumference of the circular core. Time dependent problems are analysed by using the Laplace transformation method and the Durbin’s inversion method is used to determine all the physical time dependent variables. However, in the Laplace domain, the Deng's series of stress and displacement has to be used. The accuracy and the convergence of the FBM are demonstrated by four examples. Comparisons have been made with the solutions obtained by the Boundary Collocation Method (BCM) and the Finite Element Method (FEM).
Sharif Khodaei Z, Yue N, Aliabadi MH, 2017, Damage detectability model of pitch-catch configuration in composite plates., Key Engineering Materials, Vol: 754, ISSN: 1013-9826
Detectability of damage using Lamb waves depends on many factors such as size and severity of damage, attenuation of the wave and distance to the transducers. This paper presents a detectability model for pitch-catch sensors configuration for structural health monitoring (SHM) applications. The proposed model considers the physical properties of lamb wave propagation and is independent of damage detection algorithm, which provides a generic solution for probability of detection. The applicability of the model in different environmental and operational conditions is also discussed.
Yue N, Khodaei ZS, Aliabadi MH, 2017, Damage detectability model of pitch-catch configuration in composite plates, 16h International Conference on Fracture and Damage Mechanics, FDM2017, Publisher: Trans Tech Publications, Pages: 387-390, ISSN: 1013-9826
Detectability of damage using Lamb waves depends on many factors such as size and severity of damage, attenuation of the wave and distance to the transducers. This paper presents a detectability model for pitch-catch sensors configuration for structural health monitoring (SHM) applications. The proposed model considers the physical properties of lamb wave propagation and is independent of damage detection algorithm, which provides a generic solution for probability of detection. The applicability of the model in different environmental and operational conditions is also discussed.
Morse L, Sharif Khodaei Z, Aliabadi MH, 2017, Multi-Fidelity Modeling-Based Structural Reliability Analysis with the Boundary Element Method, Journal of Multiscale Modeling, Vol: 8, ISSN: 1756-9737
In this work, a method for the application of multi-fidelity modelling to the reliability analysis of 2D elastostatic structures using the Boundary Element Method (BEM) is proposed. Reliability analyses were carried out on a rectangular plate with a centre circular hole subjected to uniaxial tension using Monte Carlo Simulations (MCS), the First Order Reliability Method (FORM), and the Second Order Reliability Method (SORM). Two BEM models were investigated, a low-fidelity model (LFM) of 20 elements and a high-fidelity model (HFM) of 100 elements. The response of these models at several design points was used to create multi-fidelity models (MFMs) utilising 2nd order polynomial response surfaces and their reliability, alongside that of the LFM and the HFM, was evaluated. Results show that the MFMs that directly called the LFM were significantly superior in terms of accuracy to the LFM, achieving very similar levels of accuracy to the HFM, while also being of similar computational cost to the LFM. These direct MFMs were found to provide good substitutes for the HFM for MCS, FORM, and SORM.
Morse L, Sharif Khodaei Z, Aliabadi MH, 2017, Reliability based impact localization in composite panels using Bayesian updating and the Kalman filter, Mechanical Systems and Signal Processing, Vol: 99, Pages: 107-128, ISSN: 1096-1216
In this work, a reliability based impact detection strategy for a sensorized composite structure is proposed. Impacts are localized using Artificial Neural Networks (ANNs) with recorded guided waves due to impacts used as inputs. To account for variability in the recorded data under operational conditions, Bayesian updating and Kalman filter techniques are applied to improve the reliability of the detection algorithm. The possibility of having one or more faulty sensors is considered, and a decision fusion algorithm based on sub-networks of sensors is proposed to improve the application of the methodology to real structures. A strategy for reliably categorizing impacts into high energy impacts, which are probable to cause damage in the structure (true impacts), and low energy non-damaging impacts (false impacts), has also been proposed to reduce the false alarm rate. The proposed strategy involves employing classification ANNs with different features extracted from captured signals used as inputs. The proposed methodologies are validated by experimental results on a quasi-isotropic composite coupon impacted with a range of impact energies.
Salmanpour MS, Khodaei ZS, Aliabadi MHF, 2017, Impact Damage Localisation with Piezoelectric Sensors under Operational and Environmental Conditions, SENSORS, Vol: 17, ISSN: 1424-8220
Guided-wave structural health monitoring (SHM) systems with piezoelectric sensors are investigated for localisation of barely visible impact damage in CFRP plates under vibration and different thermal conditions. A single baseline set is used in a delay-and-sum algorithm with temperature correction for damage localisation in a large temperature range. Damage localisation is also demonstrated under transient thermal conditions, with signals recorded while the temperature is rapidly decreased. Damage severity due to successive impact events is studied under constant temperature. Damage is also localised when the plate is subjected to random vibration.
Zou F, Aliabadi MH, 2017, On modelling three-dimensional piezoelectric smart structures with boundary spectral element method, SMART MATERIALS AND STRUCTURES, Vol: 26, ISSN: 0964-1726
Geraci G, Aliabadi MH, 2017, Micromechanical boundary element modelling of transgranular and intergranular cohesive cracking in polycrystalline materials, ENGINEERING FRACTURE MECHANICS, Vol: 176, Pages: 351-374, ISSN: 0013-7944
In this paper a cohesive formulation is proposed for modelling intergranular and transgranular damage and microcracking evolution in brittle polycrystalline materials. The model uses a multi-region boundary element approach combined with the dual boundary element formulation. Polycrystalline microstructures are created through a Voronoi tessellation algorithm. Each crystal has an elastic orthotropic behaviour and specific material orientation. Transgranular surfaces are inserted as the simulation evolves and only in those grains that experience stress levels high enough for the nucleation of a new potential crack. Damage evolution along (inter- or trans-granular) interfaces is then modelled using cohesive traction separation laws and, upon failure, frictional contact analysis is introduced to model separation, stick or slip. This is the first time inter- and trans-granular fracture are being modelled together by BEM, and DBEM is being extended to include cohesive approach for anisotropic materials. Finally numerical simulations are presented to demonstrate the validity of the proposed formulation in comparison with experimental observations and literature results.
Yeo WH, Purbolaksono J, Aliabadi MH, et al., 2017, Exact solution for stresses/displacements in a multilayered hollow cylinder under thermo-mechanical loading, INTERNATIONAL JOURNAL OF PRESSURE VESSELS AND PIPING, Vol: 151, Pages: 45-53, ISSN: 0308-0161
Mallardo V, Sharif Khodaei Z, Aliabadi MH, 2017, Sensor optimization for impact detection: A Bayesian approach, Pages: 1855-1865
A Bayesian optimization strategy resulting in optimal sensor locations for impact localization under operational conditions is developed and presented. The impact detection methodology is based on developing meta-models utilizing artificial neural network (ANN) through the recorded sensor signals generated by various impact events. The novelty of the proposed method is to include the probability of one or more sensors failing under operation as well as non-uniform probability of impact occurrence in the structure. Finally, the proposed optimization algorithm is applied to a composite stiffened panel.
Sharif Khodaei Z, Aliabadi MH, 2017, Damage Detection and Characterization with Piezoelectric transducers – Active sensing, Structural Health Monitoring For Advanced Composite Structures, Editors: Sharif Khodaei, Aliabadi
Sharif Khodaei Z, Aliabadi MH, 2017, Impact Detection and Identification with Piezoceramic Sensors – Passive sensing, Structural Health Monitoring For Advanced Composite Structures, Editors: Sharif Khodaei, Aliabadi, Publisher: Wold Scientific Publishing
Salmanpour MS, Sharif Khodaei Z, Aliabadi MH, 2016, Airborne transducer integrity under operational environment for structural health monitoring, Sensors, Vol: 16, ISSN: 1424-8220
This paper investigates robustness of permanently mounted transducers used in airbornestructural health monitoring systems, when exposed to the operational environment. Typicalairliners operate in a range of conditions, hence SHM transducer robustness and integrity mustbe demonstrated for these environments. A set of extreme temperature, altitude and vibrationenvironment test profiles are developed using the existing RTCA/DO-160 test methods. Commerciallyavailable transducers and manufactured versions bonded to CFRP composite materials are tested. Itwas found that the DuraAct transducer is robust to environmental conditions tested, while the othertransducer types degrade under the same conditions.
Mallardo V, Sharif Khodaei Z, Aliabadi MH, 2016, A bayesian approach for sensor optimisation in impact identiļ¬cation, Materials, Vol: 9, ISSN: 1996-1944
This paper presents a Bayesian approach for optimizing the position of sensors aimed at impact identification in composite structures under operational conditions. The uncertainty in the sensor data has been represented by statistical distributions of the recorded signals. An optimisation strategy based on the genetic algorithm is proposed to find the best sensor combination aimed at locating impacts on composite structures. A Bayesian-based objective function is adopted in the optimisation procedure as an indicator of the performance of meta-models developed for different sensor combinations to locate various impact events. To represent a real structure under operational load and to increase the reliability of the Structural Health Monitoring (SHM) system, the probability of malfunctioning sensors is included in the optimisation. The reliability and the robustness of the procedure is tested with experimental and numerical examples. Finally, the proposed optimisation algorithm is applied to a composite stiffened panel for both the uniform and non-uniform probability of impact occurrence.
Salmanpour MS, Sharif Khodaei, Aliabadi MH, 2016, Instantaneous baseline damage localisation using sensor mapping, IEEE Sensors Journal, Vol: 17, Pages: 295-301, ISSN: 1558-1748
In this paper an instantaneously recorded baselinemethod is proposed using piezoelectric transducers for damagelocalisation under varying temperature. This method eliminatesneed for baselines required when operating at different temper-atures by mapping a baseline area onto the interrogation area.Instantaneously recorded baselines and current interrogationsignals are calibrated based on the sensor mapping. This allowsextraction of damage scatter signal which is used to localisedamage. The proposed method is used to localise actual impactdamage on a composite plate under varying temperatures. Themethod is also applied to a stiffened fuselage panel to accuratelylocalise impact damage.
Sharif Khodaei Z, Aliabadi MH, 2016, A multi-level decision fusion strategy for condition based maintenance of composite structures, Materials, Vol: 9, ISSN: 1996-1944
In this work, a multi-level decision fusion strategy is proposed which weighs the Value of Information (VoI) against the intended functions of a Structural Health Monitoring (SHM) system. This paper presents a multi-level approach for three different maintenance strategies in which the performance of the SHM systems is evaluated against its intended functions. Level 1 diagnosis results in damage existence with minimum sensors covering a large area by finding the maximum energy difference for the guided waves propagating in pristine structure and the post-impact state; Level 2 diagnosis provides damage detection and approximate localization using an approach based on Electro-Mechanical Impedance (EMI) measures, while Level 3 characterizes damage (exact location and size) in addition to its detection by utilising a Weighted Energy Arrival Method (WEAM). The proposed multi-level strategy is verified and validated experimentally by detection of Barely Visible Impact Damage (BVID) on a curved composite fuselage panel.
Thiene M, Sharif Khodaei Z, Aliabadi MH, 2016, Optimal sensor placement for maximum area coverage (MAC) for damage localization in composite structures, Smart Materials and Structures, Vol: 25, Pages: 1-21, ISSN: 0964-1726
In this paper an optimal sensor placement algorithm for attaining the maximum area coverage (MAC) within a sensor network is presented. The proposed novel approach takes into account physical properties of Lamb wave propagation (attenuation profile, direction dependant group velocity due to material anisotropy) and geometrical complexities (boundary reflections, presence of openings) of the structure. A feature of the proposed optimization approach lies in the fact that it is independent of characteristics of the damage detection algorithm (e.g. probability of detection) making it readily up-scalable to large complex composite structures such as aircraft stiffened composite panel. The proposed fitness function (MAC) is independent of damage parameters (type, severity, location). Statistical analysis carried out shows that the proposed optimum sensor network with MAC results in high probability of damage localization. Genetic algorithm is coupled with the fitness function to provide an efficient optimization strategy.
Lopez C, Bacarreza Nogales OR, Baldomir A, et al., 2016, Reliability-based design optimization of composite stiffened panels in post-buckling regime, Structural and Multidisciplinary Optimization, Vol: 55, Pages: 1121-1141, ISSN: 1615-1488
This paper focuses on Deterministic and Reliability Based Design Optimization (DO and RBDO) of composite stiffened panels considering post-buckling regime and progressive failure analysis. The ultimate load that a post-buckled panel can hold is to be maximised by changing the stacking sequence of both skin and stringers composite layups. The RBDO problem looks for a design that collapses beyond the shortening of failure obtained in the DO phase with a target reliability while considering uncertainty in the elastic properties of the composite material. The RBDO algorithm proposed is decoupled and hence separates the Reliability Analysis (RA) from the deterministic optimization. The main code to drive both the DO and RBDO approaches is written in MATLAB and employs Genetic Algorithms (GA) to solve the DO loops because discrete design variables and highly nonlinear response functions are expected. The code is linked with Abaqus to perform parallel explicit nonlinear finite element analyses in order to obtain the structural responses at each generation. The RA is solved through an inverse Most Probable failure Point (MPP) search algorithm that benefits from a Polynomial Chaos Expansion with Latin Hypercube Sampling (PCE-LHS) metamodel when the structural responses are required. The results led to small reductions in the maximum load that the panels can bear but otherwise assure that they will collapse beyond the shortening of failure imposed with a high reliability.
Li M, Tian YL, Wen PH, et al., 2016, Anti-plane interfacial crack with functionally graded coating: static and dynamic, Theoretical and Applied Fracture Mechanics, Vol: 86, Pages: 250-259, ISSN: 0167-8442
The anti-plane displacement discontinuity method is applied to establish the Fredholm integral equation of the first kind for the orthotropic Functionally Graded Material (FGM) coatings subjected to static/dynamic shears. The shear modulus and mass density are assumed to vary exponentially through the thickness. The static and dynamic fundamental solutions with anti-plane displacement discontinuity are derived for orthotropic FGM coating by using Fourier transform method and Laplace transform method. It has been shown that the transformed fundamental solution with orthotropic coatings has the same order of hyper-singularity as in the static case, i.e. O(1/r2), and the Chebyshev polynomials of the second kind are used to solve the integral equations numerically. The time dependent stress intensity factors are obtained directly from the coefficients of the Chebyshev polynomials with the aid of Durbin’s Laplace transform inversion method. A comparative study of FGM versus homogeneous coating is conducted, and the dependence of the stress intensity factors in the coating/substrate system on the material property (orthotropic) and thickness of coating is examined. Two examples including the static/dynamic loads are given as benchmarks for the numerical methods and application in composite engineering.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.