圆截面简支梁由两根梁A、B嵌套组成，A、B之间不计摩擦，弹性模量<img src="https://static.zxtiku.com/wangke/imgs/topic/175e73a00c235ff28596dbd6b399f4fe.png"/>，则在外力偶矩<img src="https://static.zxtiku.com/wangke/imgs/topic/6a9cc4c59af6bcb841cd0505394d3155.png"/>作用下A、B中最大正应力的比值<img src="https://static.zxtiku.com/wangke/imgs/topic/f74f3cfc464a5119e0f41554818be464.png"/>为。<img src="https://static.zxtiku.com/wangke/imgs/topic/50c485145f18fd12d3ff27c8c23a8811.png"/>