8.3 Basic plastic behavior of rectangular section subjected to torsion 7力 1 T 》 ( (n) T。 max b2(3h-b) W。。b(6h-) 6 Torsinal plastic section modulus(抗扭塑性抵抗矩)8.3 Basic plastic behavior of rectangular section subjected to torsion (3 ) 6 1 2 max b h b TP    (3 ) 6 1 2 Wtp  b h  b Torsinal plastic section modulus（抗扭塑性抵抗矩）