408 Mechanics of Materials $15.7 02 6 Sheor diagonal Fig.15.6.Maximum shear stress failure envelope. and for compressive yield,with a2 compressive, 02-v01=0y Since this theory does not find general acceptance in any engineering field it is sufficient to note here,without proof,that the above equations produce the rhomboid failure envelope shown in Fig.15.7. 2 品 Shear diagonal Fig.15.7.Maximum principal strain failure envelope. (d)Maximum strain energy per unit volume theory With o3=0 this failure criterion reduces to a1+o3-2v0102= i.e. a+-2x(e)-1408 Mechanics of Materials 515.7 Fig. 15.6. Maximum shear stress failure envelope and for compressive yield, with o2 compressive, Since this theory does not find general acceptance in any engineering field it is sufficient to note here, without proof, that the above equations produce the rhomboid failure envelope shown in Fig. 15.7. 4 Fig. 15.7. Maximum principal strain failure envelope. (d) Maximum strain energy per unit oolume theory With c3 = 0 this failure criterion reduces to a:+a;-2vo,02 = 6; i.e