Open Access

ARTICLE

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 >

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1704

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ARTICLE

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 >

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1637

Open Access

ARTICLE

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 >

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1886

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ARTICLE

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 >

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1248

Open Access

ARTICLE

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 >

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