PREDIKSI DIAGRAM BATAS MAMPU BENTUK PADA LEMBARAN LOGAM

• Main Author: Akuan, Abrianto
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/5196
• Institution: Institut Teknologi Bandung

<p>Abstract: </b><p align=\"justify\"> <br /> <br /> <br /> Forming limit diagram (FLD) is a collection of forming limit strains that has been successfully used as a diagnostic tool in sheetmetal forming operations. The FLD is observed have been experimentally with forming limit test. The case that arises is how to get FLD theoretically. Approach for predicting the FLD analytically based on theories o Hill\'s anisotropic yield criterion and criteria for diffuse necking proposed by Swift.<p align=\"justify\"> <br /> <br /> <br /> Material chosen in this study is 2036. T4 aluminum alloy. Analysis of formability done with different cases in variation of strain hardening coefficient, n and plastic strain ratio, r values. In the present study, a further attempt was made to also investigate the comparative effect of FLD different classes of materials. The mayor steps involved in present methodology are study literature of mathematical model of yield criterion, step in formulation a mathematical model on prediction of FLD, procedure of calculation of forming limit strains and formation of computer program which wrote in Matlab 99 version 5.3 language.<p align=\"justify\"> <br /> <br /> <br /> The well recognized general trend of values of strain hardening coefficient n and plastic strain ratio r resulting in higher formability levels and FLDO value. The relative amounts of drawing and stretching vary in sheet metal forming operations. Where stretching predominates, formability depends mainly on n value, whereas of drawing predominates, value of r is most important. Regarding the infuence of n is most sensitive to change in values of n and r with respect to FLD vertical position. FLD moves up with increasing n value especially in biaxial stretching zone (quadrant-I). As value of r increases, the FLD moves up especially deep drawing zone (quadrant-11) and the tendency to moves down of FLD in biaxial stretching zone (quadrant I). The FLD predicted for several other material shown that C.260 copper alloys have the highest formability than 2036. T4 aluminum alloys or Aluminum killed steel and 4011 structural steel.<p align=\"justify\"> <br /> <br />