To control on the operation of sheet metal forming without failure, A diagram is used in which the range accepted, failure and critical deformation range are shown. This diagram is known as the Forming limit diagram. It is considered as one of the important tool to determine the formability of sheet metals. Every sheet metal has its own forming limit diagram which determines its formability, strain limit and the forming regions. In this paper, the forming limit diagrams (FLDs) were experimentally evaluated for low carbon steel sheets with different thickness (0.6, 0.75, 0.85, 1.2mm). The highest limit strain in the forming limit diagram is found in the steel sheet at thickness (1.2mm) and the lowest limits in the steel sheet at (0.6mm), this meaning that the formability improve with increase the thickness of steel sheet. The effect of load punch is higher at biaxial stretch path and the lowest at uniaxial tension path. The load punch is change with different thickness of sheet at the same path. The maximum thinning is found in the biaxial stretch path and the lowest of thinning in plane strain path for all sheets.
An experimental study was done on a solar water heater which consists of two prisms of orthogonal triangle cross-section with a 210 liters capacity . The heater was easy to make and has a low cost when comparted with other types of solar water heaters that it usually the collector separate on the water store. The study included experimental investigations , the experimental investigation was done under the Iraqi environmental conditions at Baghdad for the period in summer and winter seasons in 2006 but the calculation for only two days 15/7/2006 and 6/12/2006 . The study included testing the heater with & without loading and it tested in 13/12/2006and14/12/2006. draining hot water from storage tank at different rates . The experimental result show the ability to get hot water at 46oC at December i.e. a temperature rise at 30oC with 16oC initial temperature .