Inverse Dynamics Problems; Mechanical Vibration; Structural Health Monitoring
Mechanical Vibration and Measurement
Dynamics & Control
Strength of Engineering Materials
Zhang, M, Qiu, B, Kalhori, H & Qu, X 2019, 'Hybrid reconstruction method for indirect monitoring of an ice load of a steel gate in a cold region', COLD REGIONS SCIENCE AND TECHNOLOGY, vol. 162, pp. 19-34.View/Download from: Publisher's site
Kalhori, H, Alamdari, MM, Zhu, X & Samali, B 2018, 'Nothing-on-Road Axle Detection Strategies in Bridge-Weigh-in-Motion for a Cable-Stayed Bridge: Case Study', JOURNAL OF BRIDGE ENGINEERING, vol. 23, no. 8.View/Download from: UTS OPUS or Publisher's site
Zhang, M, Qu, X, Kalhori, H & Ye, L 2018, 'Indirect monitoring of distributed ice loads on a steel gate in a cold region', Cold Regions Science and Technology, vol. 151, pp. 267-287.View/Download from: Publisher's site
A steel gate is one of the major components of a hydraulic power station for storing water and monitoring the water level. In cold regions, the temperature decreases to well below the freezing point, and the water turns to ice, which can apply high loads on the steel gate, leading to large deformations and failure of the gate. This study aims to monitor and analyse the ice load distribution on a steel gate using an inverse method. As a case study, a steel gate at the hydraulic station on the Songhua River in Harbin is selected. The steel gate is equipped with several vibrating wire strain gauges, and deformation data for various locations on the structure was collected for 100 days. As experimental identification of the system transfer matrix requires information concerning the actual loads, which is not directly attainable, the transfer matrix was constructed using a finite element method. Five inverse methods were verified with a certain number of load patterns to determine the optimal method. The ice load distribution obtained using the optimal method is verified with the deformation data, indicating accurate load identification. Consequently, variation in the ice load distribution during the freezing period is monitored, and the relationship between the total ice force and temperature is obtained. During the winter of 2015–2016, the average ice line load gradually increased until reaching a maximum of approximately 25 kN/m on 11 Dec. 2015. Subsequently, the ice line load fluctuated between 17 and 25 kN/m. Finally, the ice released all of the force within 3 days beginning on 15 Mar. 2016.
Kalhori, H, Makki Alamdari, M, Zhu, X, Samali, B & Mustapha, S 2017, 'Non-intrusive schemes for speed and axle identification in bridge-weigh-in-motion systems', Measurement Science and Technology, vol. 28, no. 2, pp. 1-16.View/Download from: UTS OPUS or Publisher's site
© 2017 IOP Publishing Ltd. Bridge weigh-in-motion (BWIM) is an approach through which the axle and gross weight of trucks travelling at normal highway speed are identified using the response of an instrumented bridge. The vehicle speed, the number of axles, and the axle spacing are crucial parameters, and are required to be determined in the majority of BWIM algorithms. Nothing-on-the-road (NOR) strategy suggests using the strain signals measured at some particular positions underneath the deck or girders of a bridge to obtain this information. The objective of this research is to present a concise overview of the challenges of the current non-intrusive schemes for speed and axle determination through bending-strain and shear-strain based approaches. The problem associated with the global bending-strain responses measured at quarter points of span is discussed and a new sensor arrangement is proposed as an alternative. As for measurement of local responses rather than the global responses, the advantage of shear strains over bending strains is presented. However, it is illustrated that shear strains at quarter points of span can only provide accurate speed estimation but fail to detect the correct number of axles. As a remedy, it is demonstrated that, even for closely-spaced axles, the shear strain at the beginning of the bridge is capable of reliably identifying the number of axles. In order to provide a fully automated speed and axle identification system, appropriate signal processing including low-pass filtering and wavelet transforms are applied to the raw time signals. As case studies, the results of experimental testing in laboratory and on a real bridge are presented.
Kalhori, H, Ye, L & Mustapha, S 2017, 'Inverse estimation of impact force on a composite panel using a single piezoelectric sensor', Journal of Intelligent Material Systems and Structures, vol. 28, no. 6, pp. 799-810.View/Download from: UTS OPUS or Publisher's site
© SAGE Publications. Identification of location and magnitude of impact forces on a rectangular carbon fibre-epoxy honeycomb composite panel has been experimentally investigated through an inverse approach. The dynamic signals captured by a single piezoelectric (PZT) sensor installed on the panel remotely from the impact locations are utilized to identify the impact forces generated by an instrumented hammer. A number of potential impact locations on the panel are assumed to be known a priori. An actual impact is then occurred at one or two of these locations. The objective is to simultaneously identify the location and magnitude of the impact forces using the PZT sensor. The problem is solved through minimization of an extended matrix form of the convolution integral incorporating linear superposition of the responses due to impact at different locations. The under-determined problem is ill-posed and is regularized by Tikhonov and generalized cross validation methods. It is revealed that impact forces occurred at any location among four possible locations can be well identified.
Sun, M, Alamdari, MM & Kalhori, H 2017, 'Automated Operational Modal Analysis of a Cable-Stayed Bridge', JOURNAL OF BRIDGE ENGINEERING, vol. 22, no. 12.View/Download from: UTS OPUS or Publisher's site
Alamdari, MM, Samali, B, Li, J, Kalhori, H & Mustapha, S 2016, 'Spectral-Based Damage Identification in Structures under Ambient Vibration', JOURNAL OF COMPUTING IN CIVIL ENGINEERING, vol. 30, no. 4.View/Download from: UTS OPUS or Publisher's site
Kalhori, H, Ye, L, Mustapha, S, Li, J & Li, B 2016, 'Reconstruction and Analysis of Impact Forces on a Steel-Beam-Reinforced Concrete Deck', EXPERIMENTAL MECHANICS, vol. 56, no. 9, pp. 1547-1558.View/Download from: UTS OPUS or Publisher's site
Li, B, Ye, L, Li, Z, Ma, Z & Kalhori, H 2015, 'Quantitative identification of delamination at different interfaces using guided wave signals in composite laminates', JOURNAL OF REINFORCED PLASTICS AND COMPOSITES, vol. 34, no. 18, pp. 1506-1525.View/Download from: Publisher's site
Mareishi, S, Kalhori, H, Rafiee, M & Hosseini, SM 2015, 'Nonlinear forced vibration response of smart two-phase nano-composite beams to external harmonic excitations', Curved and Layered Structures, vol. 2, no. 1, pp. 150-161.View/Download from: Publisher's site
© 2015 S. Mareishi et al., licensee De Gruyter Open. This paper presents an analytical solution for nonlinear free and forced vibration response of smart laminated nano-composite beams resting on nonlinear elastic foundation and under external harmonic excitation. The structure is under a temperature change and an electric excitation through the piezoelectric layers. Different distribution patterns of the single walled aligned and straight carbon nanotubes (SWCNTs) through the thickness of the beam are considered. The beam complies with Euler-Bernoulli beam theory and von Kármán geometric nonlinearity. The nonlinearity is due to the mid-plane stretching of the beam and the nonlinear stiffness of the elastic foundation. The Multiple Time Scales perturbation scheme is used to perform the nonlinear dynamical analysis of functionally graded carbon nanotube-reinforced beams. Analytical expressions of the nonlinear natural frequencies, nonlinear dynamic response and frequency response of the system in the case of primary resonance have been presented. The effects of different parameters including applied voltage, temperature change, beam geometry, the volume fraction and distribution pattern of the carbon nanotubes on the nonlinear natural frequencies and frequency-response curves are presented. It is found that the volume fractions of SWCNTs as well as their distribution pattern significantly change the behavior of the system.
Hosseini, SM, Kalhori, H, Shooshtari, A & Mahmoodi, SN 2014, 'Analytical solution for nonlinear forced response of a viscoelastic piezoelectric cantilever beam resting on a nonlinear elastic foundation to an external harmonic excitation', COMPOSITES PART B-ENGINEERING, vol. 67, pp. 464-471.View/Download from: Publisher's site
Hosseini, SM, Mareishi, S, Kalhori, H & Rafiee, M 2014, 'Large Amplitude Free and Forced Oscillations of Functionally Graded Beams', MECHANICS OF ADVANCED MATERIALS AND STRUCTURES, vol. 21, no. 4, pp. 255-262.View/Download from: Publisher's site
Hosseini, SM, Shooshtari, A, Kalhori, H & Mahmoodi, SN 2014, 'Nonlinear-forced vibrations of piezoelectrically actuated viscoelastic cantilevers', NONLINEAR DYNAMICS, vol. 78, no. 1, pp. 571-583.View/Download from: Publisher's site
Shooshtari, A, Hoseini, SM, Mahmoodi, SN & Kalhori, H 2012, 'Analytical solution for nonlinear free vibrations of viscoelastic microcantilevers covered with a piezoelectric layer', SMART MATERIALS AND STRUCTURES, vol. 21, no. 7.View/Download from: UTS OPUS or Publisher's site
Hosseini, SM, Al-Jumaily, A & Kalhori, H 2017, 'Tremor suppression in wrist joint using active force control method', 9th Australasian Congress on Applied Mechanics, ACAM 2017, Australasian Congress on Applied Mechanics, Engineers Australia, Sydney, NSW.View/Download from: UTS OPUS
© 2017 National Committee on Applied Mechanics. All Rights Reserved. Tremor is a neurological disorder characterized by involuntary oscillations. Difficulties associated with tremor in patients with Parkinson's disease have motivated the researchers to work on developing various methods for tremor suppression. Active Force Control (AFC) method for tremor attenuation in human body parts is considered in this work. This paper proposes a new AFC system based on a piezoelectric actuator. A three-degree-of-freedom musculoskeletal model including wrist flexion-extension (FE), radial-ulnar deviation (RUD), and pronation supination (PS) is developed for studying tremor in the wrist joint. The musculoskeletal model for this study contains four muscles; extensor carpi radialis longus, extensor carpi ulnaris, flexor carpi ulnaris and flexor carpi radialis. Also, the muscle model is developed from the classic Hill-type muscle model. First, simulation of the tremor generation in the model is performed and then the performance of AFC system for suppressing wrist joint tremor is investigated. A single piezoelectric actuator is embedded in AFC system for controlling the behavior of the classic proportional-derivative controller. MATLAB Simulink is used to analyze the model. Results show that the AFC-based system with a piezoelectric actuator and a PD controller is very effective in suppressing the human hand tremor.
Makki Alamdari, M, Khoa, N, Rakotoarivelo, T, Kalhori, H & Li, J 2017, 'Structural health monitoring in the Sydney harbour bridge using spectral moments', SHMII 2017 - 8th International Conference on Structural Health Monitoring of Intelligent Infrastructure, Proceedings, Structural Health Monitoring of Intelligence Infrastructure Conference, Brisbane, Australia, pp. 481-490.
© 2017 International Society for Structural Health Monitoring of Intelligent Infrastrucure. All rights reserved. The motivation behind this paper is to develop a spectral-based damage identification scheme using output only acceleration responses. The presented method is in the context of non-model-based damage identification methods and does not require any representative numerical/analytical model of the structure. The method utilizes spectral moments of the response as damage sensitive feature. Spectral moments directly retrieve information from the power spectral density of the response. Unlike the modal data that only provide information at a limited number of eigen-frequencies, spectral moments capture information from the entire spectra, hence they can distinguish any subtle differences between a normal and distorted signal. The feasibility of the approach in damage identification was validated using real data from the Sydney Harbour Bridge. There are approximately 800 jack arches over a total distance of 1.2 km need to be continuously monitored. For this study, two instrumented jack arches were considered. These joints are located on the eastern side of the bridge underneath the bus lane near the north pylon. One of these two joints had a known crack in 2012, along the front face propagating toward the surface of the deck, while the other joint was intact. This damage was repaired in 2013. Acceleration data were collected from tri-axial accelerometers mounted on the base of each joint before and after repair. The presented spectral-based method along with the hypothesis testing involving the KS-test were applied to obtain a decision on whether or not the structure is damaged. Spectral moments with different orders were also investigated. It was demonstrated that the proposed spectrum-driven feature can reliably distinguish between the healthy and damaged joints which is of great importance for the asset owner. The presented results illustrated high potent...
Sadeghi, S, Kalhori, H, Tabassum, M, Fu, K, Ye, L & Kinloch, A 2017, 'Characterization of Mode I fracture behavior of a shear thickening fluid using a cohesive zone model', 9th Australasian Congress on Applied Mechanics, ACAM 2017.
© 2017 National Committee on Applied Mechanics. All Rights Reserved. The fracture behavior of double cantilever-beam (DCB) specimens with a shear thickening fluid (STF) as an adhesive layer is investigated numerically. The mode I fracture toughness of the STF appears to increase with an increase in the opening displacement rate, showing brittle fracture at high loading rates. In this study, a rate-dependent cohesive zone model (CZM), following a bilinear traction-separation behavior, is introduced, in which the rate-dependency of the fracture toughness, initial stiffness, and cohesive stress are incorporated. A linear dependence of the CZM parameters on the strain rate based on a logarithmic relationship is proposed. The model is then validated by comparing the predictions with the experimental results, and good agreement is found. It is shown that the use of a well-founded rate-dependent numerical model is crucial for modeling a shear thickening fluid as an adhesive material subjected to various loading rates.
Alamdari, MM, Khoa, NLD, Rakotoarivelo, T, Kalhori, H & Mustapha, S 2016, 'Damage identification in the concrete jack arch bridge using spectral moments', MAINTENANCE, MONITORING, SAFETY, RISK AND RESILIENCE OF BRIDGES AND BRIDGE NETWORKS, 8th International Conference on Bridge Maintenance, Safety and Management (IABMAS), CRC PRESS-TAYLOR & FRANCIS GROUP, Foz do Iguacu, BRAZIL, pp. 548-548.
Alamdari, MM, Khoa, NLD, Rakotoarivelo, T, Kalhori, H & Mustapha, S 2016, 'Damage identification in the concrete jack arche bridge using spectral moments', Maintenance, Monitoring, Safety, Risk and Resilience of Bridges and Bridge Networks - Proceedings of the 8th International Conference on Bridge Maintenance, Safety and Management, IABMAS 2016, International Conference on Bridge Maintenance, Safety and Management (IABMAS), CRCNet, Foz Do Iguacu, Brazil, pp. 2271-2276.
© 2016 Taylor & Francis Group, London.The motivation behind this paper is to develop a spectral-based damage identification scheme using output only acceleration response. The method utilizes spectral moment of the response as damage sensitive feature. Spectral moments retrieve information directly from the power spectrum. The major advantages of the method include, first, the method works based on the output only measurement data without demanding any representative model of the structure; second, unlike modal data, the presented method is a broadband approach which implements information from a wide frequency range. The feasibility of the approach in damage identification was validated using real data from the Sydney Harbour Bridge. Currently the bridge carries eight lanes of road traffic and two railway lines. Traffic lane 7 is a dedicated bus and taxi lane on the Eastern side of the bridge. Lane 7 consists of an asphalt road surface on a concrete deck supported by concrete and steel jack arches. There are approximately 800 jack arches over a total distance of 1.2 km. The jack arches are physically very difficult to access and are inspected typically at two yearly intervals according to standard visual inspection practices. For this study, three instrumented jack arches were considered. These joints are located on the eastern side of the bridge underneath the bus lane near the north pylon. One of the joints had a known crack, along the front face and the crack propagated toward the surface of the deck, while the other joints were intact: one very far from the damaged joint and the other one very close to the damaged joint. Acceleration data were collected from tri-axial accelerometers mounted on the base of each joint; data were collected before and after repair conducted on the damaged joint. The presented method was applied to see whether the presence of crack in the damaged joint can be identified and to investigate the impact of repair on the damaged joint...
Kalhori, H, Ye, L, Li, Z & Li, B 2015, 'IDENTIFICATION OF LOCATION AND MAGNITUDE OF IMPACT FORCE ON A COMPOSITE SANDWICH STRUCTURE WITH LATTICE TRUSS CORE', PROCEEDINGS OF THE ASME INTERNATIONAL MECHANICAL ENGINEERING CONGRESS AND EXPOSITION, 2015, VOL 1, ASME International Mechanical Engineering Congress and Exposition (IMECE2015), AMER SOC MECHANICAL ENGINEERS, Houston, TX.
Kalhori, H, Ye, L, Mustapha, S & Li, J 2014, 'Impact force reconstruction on a concrete deck using a deconvolution approach', 8th Australasian Congress on Applied Mechanics, ACAM 2014, as Part of Engineers Australia Convention 2014, Australasian Congress on Applied Mechanics, Informit, Melbourne, Australia, pp. 763-771.View/Download from: UTS OPUS
In this study, impact force history applied to a steel-reinforced concrete deck has been reconstructed based on vibration response signals collected at random positions from the impact location. A deconvolution technique in time domain utilizing the responses recorded, from piezoelectric (PZT) sensors and accelerometers are used to reconstruct the impact force. As the deconvolution is an ill-conditioned inverse problem, the truncated singular value decomposition (TSVD) and the Tikhonov regularization are used to regularize the problem. The effect of different attachment methods of the PZTs/accelerometers on the structure is investigated including the use of Blu-tack and the 5-minnutes Araldite. It is found that with the use of the Blu-tack, the reconstructed force is not predicted precisely which can be attributed to the nonlinear behaviour of the Blu-tack. In addition, the effect of the location of the measurement point on quality of reconstructed impact force is investigated. It is found that when the measurement location is very close to the impact site, there is no need to use the regularization techniques and the pseudo-inverse method can provide acceptable results.