NON-LINEAR DYNAMIC BEHAVIOR OF THERMOELASTIC CIRCULAR PLATE WITH VARYING THICKNESS SUBJECTED TO NONCONSERVATIVE LOADING

The non-linear dynamic behaviors of thermoelastic circular plate with varying thickness subjected to radially uniformly distributed follower forces are considered. Two coupled non-linear differential equations of motion for this problem are derived in terms of the transverse deflection and radial displacement component of the mid-plane of the plate. Using the Kantorovich averaging method, the differential equation of mode shape of the plate is derived, and the eigenvalue problem is solved by using shooting method. The eigencurves for frequencies and critical loads of the circular plate with unmovable simply supported edge and clamped edge are obtained. The effects of the variation of thickness and temperature on the frequencies and critical loads of the thermoelastic circular plate subjected to radially uniformly distributed follower forces are then discussed.

Forming and Springback Prediction of Strips Under Multi-square Punch Concave Forming Process Considering Partial-unloading Effects

To further investigate the forming mechanism and springback characteristics of strips under multi-square punch forming (MSPF) considering partial-unloading effects, a series of concave form ing tests of strips are conducted on the MSPF machine. This paper aims to reveal the physical mecha nism of the elastic-plastic deformation in the MSPF process considering the effect of the forming ap proaches, and derive appropriate mathematical interpretations. The theoretical model is firstly estab lished to analyse the concave forming mechanism and springback characteristics of the strip, and its accuracy is then validated by experimental data. The forming history and load evolutions are depicted to explore the required forming capacity through the proposed analytical method. Besides, the paramet ric studies are carried out to discuss their effects on the springback of the strip. The results suggest that the deformation paths of the strip are influenced by the forming approach, and the springback of the strip in convex forming is larger than that in concave forming.

Life cycle evaluation of an intercooled gas turbine plant used in conjunction with renewable energy

The life cycle estimation of power plants is important for gas turbine operators.With the introduction of wind energy into the grid,gas turbine operators now operate their plants in Load–Following modes as back-ups to the renewable energy sources which include wind,solar,etc.The motive behind this study is to look at how much life is consumed when an intercooled power plant with 100 MW power output is used in conjunction with wind energy.This operation causes fluctuations because the wind energy is unpredictable and overtime causes adverse effects on the life of the plant–The High Pressure Turbine Blades.Such fluctuations give rise to low cycle fatigue and creep failure of the blades depending on the operating regime used.A performance based model that is capable of estimating the life consumed of an intercooled power plant has been developed.The model has the capability of estimating the life consumed based on seasonal power demands and operations.An in-depth comparison was undertaken on the life consumed during the seasons of operation and arrives at the conclusion that during summer,the creep and low cycle life is consumed higher than the rest periods.A comparison was also made to determine the life consumed between Load–Following and stop/start operating scenarios.It was also observed that daily creep life consumption in summer was higher than the winter period in-spite of having lower average daily operating hours in a Start–Stop operating scenario.