Characterisation and modelling friction at the tool-ply interface for thermoplastic woven composites
Press forming of thermoplastic textile composites is a 
fast and efficient method of production. Friction 
occurring between the composite material and pressure 
blank-holder during forming imparts tensile stresses in 
the sheet which help counteract compressive stresses 
generated by material deformation; stresses that can 
result in unwanted wrinkling of the forming sheet. In 
order to model the press forming process and optimise 
boundary conditions, this friction behaviour must be 
characterised and modelled. Two different test methods 
are employed to characterise the friction and two 
complementary modelling strategies, an empirical and a 
predictive approach, are presented.
Composite preforming defects: a review and a classification
Advancing in the process of extending the use of composites for structural parts applications, it is inevitable to work on complex shapes. That is the main reason why understanding the complex forming mechanisms and the factors put into play during the process of composite materials is a major interest for both pre-impregnated forming and dry fabric preforming. Thus, the appearance of defects is a major concern and predicting their appearance for optimal product quality is the priority. A great number of authors showed that defects degrade the overall performance of the composite by creating local heterogeneities. Many factors can initiate these defects. This article is an assembly of the development of the literature on this subject. It is an attempt to provide a description for each defect and a classification order following the scale, the behavior mechanisms, the appearance plan. This will help to converge toward an identification of the defects manifesting during the composite forming.
Suitability and water quality criteria of an open drainage municipal sewage water at Coimbatore, used for irrigation.
Sanganur canal is the major open drainage system which has intricate linkage with storm water supply, domestic sewage and industrial effluent disposal. Water samples from various stations were collected and analysed for physicochemical parameters to assess the water quality of the Sanganur canal system. The study revealed that physicochemical parameters like pH, EC, TDS, DO, BOD, COD exceeded the permissible limit, clearly indicating the need of proper treatment of waste water before discharge into the Noyyal river.