问题 单项选择题

关于悬臂梁变形大小的影响因素,下列表述不正确的是( )。

A.跨度越大,变形越大

B.截面的惯性矩越大,变形越大

C.截面积越大,变形越小

D.材料弹性模量越大,变形越小

答案

参考答案:B

解析:[考点] 1A411012掌握房屋结构的适用性要求
影响梁变形(位移)的因素有跨度、材料、截面形状、外部荷载、支座情况等。要求考生要掌握均布荷载作用下悬臂梁的最大变形公式([*])中各影响因素与变形的关系,如与梁变形(位移)成正比的因素有跨度、荷载,成反比的因素有惯性矩、弹性模量等,此处知识点可出多选题。而所有因素中影响最大的是跨度(L),此处也可出计算式的单项选择题,如当梁的跨度增加1倍时,其变形增大到原来的多少倍(16倍)。

阅读理解

The earth moves around the sun, and the moon moves around the earth. When our part of the earth turns to the moon, it is night.

The sun is much bigger than the moon. But sometimes the moon looks bigger than the sun, because it’s much nearer to the earth.

The sun is very bright. It gives a very strong light. The moon looks quite bright, too. But it doesn’t give any light at all.

The moon looks much bigger and brighter than the stars. But actually(实际上) the stars are much bigger and brighter than the moon. They look smaller than the moon because they’re much farther away from us.

小题1:____moves around________.

A.The earth; the moon

B.The moon; the earth

C.The moon; the stars

D.The sun; the earth小题2:Sometimes the moon looks bigger than the sun, because_________.

A.it is much bigger than the sun

B.it comes out only at night

C.it is much nearer to the earth than the sun

D.it doesn’t give a strong light小题3:The sun_______________.

A.is very bright, and it gives a very strong light

B.isn’t bright, but it gives a very strong light

C.is very big, but it doesn’t give any light at all

D.is very round, but it can’t move round小题4:The stars______________.

A.look much bigger than the moon

B.look much bigger than the sun

C.are a lot brighter than the moon, but they are not bigger than the moon

D.are much farther away from us than the moon小题5:When                            ,it is day.

A.our part of the earth turns to the moon

B.our part of the earth turns to the sun

C.the sun moves

D.the moon moves

多项选择题