P Sriram

This paper applies a mixed-mode delamination onset criterion to predict edge delamination in quasi-isotropic laminates of IM7/8320 and IM7/5260. The laminates were tested statically and in fatigue at 23 and 175°C. The three stages involved in this process were: (1) determination of the mixed-mode ratio, (2) determination of the mixed-mode delamination onset criterion using the mixed-mode bending apparatus, and (3) comparison with experimental data. To determine the mixed-mode ratio, several finite element analysis (FEA) models were created with different element sizes at the delamination front and with resin layers also modeled. The β = 0 approach was employed to converge the FEA results. Surface fits were made to the mixed-mode data to allow for prediction of the flat laminate experimental data. The influence of the Mode II component in the predictions resulted in the predictions being less conservative than using a Mode I failure criterion, although the predictions were still conservative.

Several higher educational institutions are now emerging in the private sector, which are much larger than the traditional high performing Government funded institutions like the Indian Institute of Science (IISc) and the IITs. We identify seven such mega institutions and use the bibliometric and financial data from NIRF 2017 to see how they compare with IISc when both research excellence and socio-economic performance are taken into account. Apart from other legacy and perception factors that attract the best faculty to premier institutions, the capital expenditure per faculty per year must be increased by 5 to 50 times as the case may be, before these universities can become attractive destinations for the best and brightest of aspiring faculty.

Experimental studies are carried out to determine the interlaminar fracture toughness of unidirectional laminates made of M55J/M18 carbon/epoxy material under different mixed mode ratios (GI /GII ). A mixed mode delamination fracture criterion using mixed mode bending specimens is developed. It is observed that when loading in mode I is predominant, GII has a considerable value but the opposite is not true when mode II is predominant.