单项选择题
以下组件由两个直径为30mm的红黄铜棒AB和CD、一个直径为40mm的钢合金棒EF和一个刚性盖G组成。如果A、C和F处的支座是刚性的,AB和EF中产生的平均应力是()。
A.20.5MPa,33.8MPaB.26.5MPa,31.8MPaC.22.5MPa,31.8MPaD.26.5MPa,33.8MPa
A.P/2,P/2B.6P/17,11P/17C.10P/17,7P/17D.8P/17,9P/17
A.80.2MPa,71.0MPaB.102.0MPa,50.9MPaC.121.0MPa,36.0MPaD.138.2MPa,21.0MPa