Drilling-induced damage

Delamination is one of the most common damage forms associated with drilling of polymer composites. The most common types of drilling-induced damage mechanisms are peel-up delamination at entrance and push-down delamination at exit side of the drilled hole. The various other types of drilling-induced damage found are fibre... 

Drilling-induced damage in unidirectional GFRP laminates... 

The ANN topology was adopted as a predictive tool. The cutting speed, feed rate, drill diameter and drill point geometry were nsed as the input parameters. The drilling-induced damage was the output. The maximum absolute error for training patterns was found to be 12.7 per cent and the minimum was 0.1 per cent, and for most cases the error was less than 5 per cent. The maximum absolute error for testing patterns was found to be 13.19 per cent and the minimum was 0.35 per cent (Mishra et al., 2010). 

The previous section dealt with application of soft computing techniques for developing predicting models for drilling forces and drilling-induced damage in PMCs. This section... 

Mishra, R., Malik, J. and Singh, 1. (2010) Prediction of drilling-induced damage in unidirectional glass fiber reinforced plastic laminates using an artificial neural network, PI MECH ENG B-J ENG, 224 733-8. 

Stonemasons are at risk of hand-arm vibration when using chipping hammers, angle grinders, drills, disk cutters, air rammers and abrasive wheels. Vibration-induced vasospastic disease, such as vibration white finger, or bone and joint disorders, such as carpal tunnel syndrome, are the most common diseases [8-10]. Damage to blood circulation, nerves and muscles may influence occupational skin disease. 

The irritant effects of surfactants have been discussed earlier. Cutaneous toxicity has recently been dealt with in some detail in a symposium volume edited by Drill and Lazar [229]. The damage surfactants can cause to the barrier layer of the skin can potentiate the toxicity of other substances. 5% NADS doubles the permeation rate of water after 1 h [230] and markedly reduced the amount of bound water in the tissues [231]. Increased penetration induced by surfactants is largely due, however, to keratin denaturation accompanied by tissue swelling [232]. 

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