F. Balle¹, S. Huxhold¹, G. Wagner¹, D. Eifler¹

Structural Durability & Health Monitoring, Vol.8, No.4, pp. 359-370, 2012, DOI:10.32604/sdhm.2012.008.359

Abstract Aluminum alloys and carbon fiber reinforced polymers (CFRP) are two important materials for lightweight design and the combination of these dissimilar materials becomes increasingly important. Recent investigations have shown that ultrasonic metal welding is a well suited process to realize aluminum/CFRP-joints.The ultrasonic shear oscillation parallel to the welding zone with a simultaneous welding force perpendicular to the aluminum/CFRP-sheets melts the polymer matrix and squeezes the polymer matrix out of the welding zone. This allows a direct contact between the carbon fibers and the aluminum. Beside monotonic properties the cyclic deformation behavior of these ultrasonically welded More >

A. Rama Mohan Rao¹, S. Krishna Kumar¹, K. Lakshmi¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 271-294, 2012, DOI:10.32604/sdhm.2012.008.271

Abstract Current advancements in structural health monitoring, sensor and sensor network technologies have encouraged using large number of sensor networks in monitoring spatially large civil structures like bridges. Large amount of spatial information obtained from these sensor networks will enhance the reliability in truly assessing the state of the health of the structure. However, if sensors go faulty during operation, the feature extraction techniques embedded into SHM scheme may lead to an erroneous conclusion and often end up with false alarms. Hence it is highly desirable to robustly detect the faulty sensors, isolate and correct the… More >

Biao Zhou^1,2,3, Xiong yao Xie^1,2, Yeong Bin Yang⁴, Jing Cai Jiang³

CMES-Computer Modeling in Engineering & Sciences, Vol.86, No.4, pp. 321-348, 2012, DOI:10.3970/cmes.2012.086.321

Abstract The vibration-based SHM (Structure Health Monitoring) system has been successfully used in bridge and other surface civil infrastructure. However, its application in operation tunnels remains a big challenge. The reasons are discussed in this paper by comparing the vibration characteristics of the free tunnel structure and tunnel-soil coupled system. It is revealed that all the correlation characteristics of the free tunnel FRFs (Frequency Response Function spectrum) will vanish and be replaced by a coupled resonance frequency when the tunnel is surrounded by soil. The above statement is validated by field measurements. Moreover, the origin of More >

Clyde K Coelho, Cristobal Hiche, Aditi Chattopadhyay

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 65-82, 2011, DOI:10.3970/sdhm.2011.007.065

Abstract Low velocity impacts on composite plates often create subsurface damage that is difficult to diagnose. Fiber Bragg grating (FBG) sensors can be used to detect subsurface damage in composite laminates due to low velocity impact. This paper focuses on the prediction of impact loading in composite structures as a function of time using a support vector regression approach. A time delay embedding feature extraction scheme is used since it can characterize the dynamics of the impact using the sensor signals. The novelty of this approach is that it can be applied on complex geometries and… More >

Dennis Bäcker¹, Andreas Ricoeur², Meinhard Kuna¹

Structural Durability & Health Monitoring, Vol.7, No.1&2, pp. 1-22, 2011, DOI:10.3970/sdhm.2011.007.001

Abstract A new sensor concept for monitoring fatigue crack growth in technical structures is presented. It allows the in-situ determination of the position of the crack tip as well as the fracture mechanical quantities. The required data are obtained from a piezoelectric polymer film, which is attached to the surface of the monitored structure. The stress intensity factors and the crack tip position are calculated from electrical potentials obtained from a sensor array by solving the non-linear inverse problem. More >

Hyung-Jo Jung, Jong-Jae Lee, Jeong-Su Park

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 125-126, 2011, DOI:10.3970/icces.2011.019.125

Abstract A vision-based displacement measurement method for structural health monitoring of large-scale infrastructures such as high-rise buildings and long-span bridges is presented. The method uses digital image processing techniques including a target recognition algorithm, projection of the captured image, and calculation of the actual displacement using target geometry and the number of pixels moved. To measure the displacement of a flexible structure from a distant location which can be regarded as a fixed reference point, a novel image processing method has been devised by means of successive estimation of relative displacement and rotational angle using a More >

Choong- Han Han, Hei-Sook Nah, Won-Sik Choi, Ki-Beom Ju, Jong-Kwan Song

The International Conference on Computational & Experimental Engineering and Sciences, Vol.18, No.3, pp. 87-88, 2011, DOI:10.3970/icces.2011.018.087

Abstract This study is aimed at improving the safety and maximizing construction productivity by effectively grafting SOC facility construction material to RFID/USN technology for the purpose of science in the maintenance of SOC facility. More >

David CC LAM^*, Leo K-K LEUNG, Match W-L KO, R. G-Z CHEN, I-S CHAN

The International Conference on Computational & Experimental Engineering and Sciences, Vol.20, No.3, pp. 85-86, 2011, DOI:10.3970/icces.2011.020.085

Abstract The eye is a biomechanical organ where the health of the optical nerves and vision are affected by the intrCular pressure and the ocular tissue structure. The ocular pressure is the primary parameter monitored by opticians and ophthalmologists to determine the ocular health of the eye to prevent glaucoma where 50% of the vision can be lost before detection by the patient. Elevated intrCular pressure is clinically correlated with the degeneration of the optic nerves, but the biomechanical mechanism for the degeneration remains speculative. In this study, we present the results from biomechanical modeling of More >

Q Wang^*, YP Zheng^∗,†, HJ Niu^∗,‡

Molecular & Cellular Biomechanics, Vol.7, No.1, pp. 45-58, 2010, DOI:10.3970/mcb.2010.007.045

Abstract This study aims to obtain osmosis-induced swelling strains of normal and proteoglycan (PG) depleted articular cartilage using an ultrasound system and to investigate the changes in its mechanical properties due to the PG depletion using a layered triphasic model. The swelling strains of 20 cylindrical cartilage-bone samples collected from different bovine patellae were induced by decreasing the concentration of bath saline and monitored by the ultrasound system. The samples were subsequently digested by a trypsin solution for approximately 20 min to deplete proteoglycans, and the swelling behaviors of the digested samples were measured again. The… More >

S. Ullah¹, B. Pichler¹, S. Scheiner^1,2, C. Hellmich^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.3, pp. 279-316, 2010, DOI:10.3970/cmes.2010.057.279

Abstract Point-wise optical measurements of 3D displacement vectors over time are a key input for monitoring shotcrete tunnel shells during construction according to the New Austrian Tunnelling Method (NATM). Aiming at estimation of the stresses prevailing in the highly loaded, hydrating material, we here deal with two different interpolation strategies for reconstructing, from measured displacement vectors, the 3D displacement field histories of the inner surface of the tunnel shell. The first approach considers spatial interpolation of displacement components in a fixed Cartesian base frame, while the second (new) approach refers to displacement components in a moving… More >