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 >

Leandro Fleck Fadel Miguel¹, Letícia Fleck Fadel Miguel²

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 249-270, 2012, DOI:10.32604/sdhm.2012.008.249

Abstract Model updating may be defined as an adjustment on the FE model through modal parameters experimentally obtained, in order to better represent its dynamic behavior. From this definition, structural health monitoring (SHM) methods can be considered closely related with these procedures, because it refers to the implementation of in situ non-destructive sensing and analysis of the dynamic system characteristics, which aims to detect changes that could indicate damage. Within this context, the present paper evaluates an iterative model updating approach when it is subjected to experimental vibration data. In addition, after getting the experimental adjusted… More >

P.H. Wen¹, M.H. Aliabadi²

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 223-248, 2012, DOI:10.32604/sdhm.2012.008.223

Abstract A mesh-free method for modelling crack growth in functionally graded materials is presented. Based on the variational principle of the potential energy, mesh-free method has been implemented with enriched radial bases interpolation functions to evaluate mixed-mode stress intensity factors, which are introduced to capture the singularity of stress at the crack tip. Paris law and the maximum principle stress criterion are adopted for defining the growth rate and direction of the fatigue crack growth respectively. The accuracy of the proposed method is assessed by comparison to other available solutions. More >

K.N. Song¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 209-222, 2012, DOI:10.32604/sdhm.2012.008.209

Abstract A PHE (Process Heat Exchanger) is a key component in transferring the high temperature heat generated from a VHTR (Very High Temperature Reactor) to the chemical reaction for the massive production of hydrogen. A performance test on a small-scale PHE prototype made of Hastelloy-X is currently under way a small-scale gas loop at the Korea Atomic Energy Research Institute. Previous research on the elastic high-temperature structural analysis of the small-scale PHE prototype has been performed using the parent material properties over the whole region. In this study, an elastic-plastic high-temperature structural analysis considering the mechanical More >

He Xufei¹, Deng Zhongmin², Song Zhitao¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 193-208, 2012, DOI:10.32604/sdhm.2012.008.193

Abstract This paper describes an information optimizing scheme which is developed by integrating rough set and hierarchical data fusion. The novel structural damage indices are extracted using the information from different sources and then imported into probabilistic neural network (PNN) for classification and health assessment. In order to enhance the accuracy of diagnosis, results from separate PNN classification are fused to achieve comprehensive decision. Rough set is employed to decrease the spatial dimension of data. The predictive accuracy of optimizing scheme is demonstrated on a helicopter, taken as an example, with varied sensors, for multiple damage More >

D. Crivelli¹, M. Guagliano², A. Monici³

Structural Durability & Health Monitoring, Vol.8, No.2, pp. 177-192, 2012, DOI:10.3970/sdhm.2012.008.177

Abstract Pultrusion is a process for manufacturing uniform section composite profiles, which allows to obtain structural elements of virtually any length. The use of E-glass fiber allows to obtain a material with a good rigidity-to-weight and strength-to-weight ratio; these features allowed to use these materials in civil structures, such as poles for anti-noise panels and public lighting, also thanks to their insulating properties. However, the knowledge on the damage development of these materials is still uncertain, and this is slowing down their development.
For these reasons, an experimental study on pultruded materials aimed at identifying the damage… More >

G. Pitarresi¹

Structural Durability & Health Monitoring, Vol.8, No.2, pp. 149-176, 2012, DOI:10.3970/sdhm.2012.008.149

Abstract The present work describes the implementation of active IR Thermography techniques for the NDT of thick polymer and glass-fibre reinforced polymer (GRP) composite panels. A low cost Thermal NDT set-up is proposed, comprising a single-detector IR camera with low thermal resolution and low frame rate, and common low-power halogen lamps as external heat source devices. The use of halogen lamps in particular requires several seconds of switch-on time in order to deliver meaningful and effective heat quantities. The influence of such long heat deposition intervals is investigated on the possibility to implement Transient Thermography and More >

G. Nicoletto¹, A. Saletti²

Structural Durability & Health Monitoring, Vol.8, No.2, pp. 131-148, 2012, DOI:10.3970/sdhm.2012.008.131

Abstract Fatigue strengthening of fillets by deep rolling is finding increased application for example in engine crankshaft production for functional and economical reasons. A fatigue design method aimed at exploiting the residual stresses that develop at a notched part following the rolling process is proposed. It is based on the superposition of residual stresses obtained by elastic-plastic FE simulation of the rolling process and the cyclic elastic stresses within a Haigh diagram framework. The fatigue design method is assessed using the experimental evidence obtained by testing notched specimens made of 30NiCrMo12 steel subjected to different rolling More >

G. Meneghetti¹

Structural Durability & Health Monitoring, Vol.8, No.2, pp. 111-130, 2012, DOI:10.3970/sdhm.2012.008.111

Abstract This paper deals with the local approach based on the Notch Stress Intensity Factors (NSIFs) to analyse the fatigue behavior of welded joints. In transverse load carrying fillet-welded joints, failure may occur either at the toe or at the root, depending on the geometry. At the toe, due to the flank angles that are usually encountered in practice, mode I local stresses are singular, while mode II stresses are not. Conversely, at the root of the particular joints analysed in the present paper both mode I and mode II stresses are singular and must be… More >

A. Risitano¹, D. Corallo¹, G. Risitano²

Structural Durability & Health Monitoring, Vol.8, No.2, pp. 91-110, 2012, DOI:10.3970/sdhm.2012.008.091

Abstract According to Miner's rule, the fatigue life of a material (or a mechanical component) is not a function of the order of the application of load. Many authors have already observed that the model proposed by Palmgren/Miner leads to underestimation of the damage and one of the reasons could be the disregard of the sequence of loads. Referring to the energy loss related to irreversible damage of the material, it was observed that the Miner's rule gives exact results only if the damage caused by the fatiguing load is low compared to the limit energy More >