问题 单项选择题

某冶金工厂操作平台横剖面如图所示。平台承受由检修材料所产生的均布活荷载标准值为20kN/m2,平台结构自重为2kN/m2,每跨横梁中部设有检修单轨吊车,其作用荷载标准值F=100kN,每片框架承受水平活荷载标准值H=50kN,平台柱自重可忽略不计。

平台梁跨度9m,柱距5m,柱高6m,柱顶与横梁铰接,柱底与基础固接,各列柱纵向均设有柱间支撑,柱顶纵向有可靠支承,平台面铺钢板,与横梁焊接。

平台结构采用Q235-B·F(3号钢)制作,在框架平面内,中柱截面惯性矩为边柱的2倍,中柱截面为钢板焊成的实腹工形柱,如题图,两翼缘为-250mm×25mm,腹板为 -450mm×l2mm。ix=21.1cm,iy=6.03cm,Wx=3187cm3

柱CD在N=1126kN、Mx=210kN·m作用下,截面最大应力是()。

A.108.3N/mm2

B.125.7N/mm2

C.149.1N/mm2

D.171.4N/mm2

答案

参考答案:B

解析:

根据《钢结构设计规范》(GB 50017—2003),本题柱不承受My查表5.2.1,截面塑性发展系数γx=1.05,强度

阅读理解

Some people believe that international sport creates goodwill between the nations and that if countries play games together, they will learn to live together. Others say that the opposite is true: international competitions encourage false national pride and lead to misunderstanding and hatred. There is probably some truth in both arguments, but in recent years the Olympic Games have done little to support the view that sport encourages international brotherhood. Not only was there the tragic incident including the murder of athletes, but the Games were also ruined by incidents caused mainly by smaller national contests.

One country received its second-place medals with visible anger after the hockey final. There had been noisy scenes at the end of the hockey match, the losers objecting to the final decisions. They were sure that one of their goals should not have been disallowed and that their opponents’ victory was unfair. Their manager was in great anger when he said, “This wasn’t hockey. Hockey and the International Hockey Federation are finished.” The president of the Federation said later that such behavior could result in the suspension(停赛)of the team for at least three years.

Incidents of this kind will continue as long as sport is played competitively rather than for the love of the game. The suggestion that athletes should compete as individuals, or in non-national teams, might be too much to hope for. But in the present organization of the Olympics there is far too much that encourages  aggressive patriotism(爱国主义).

小题1:According to the author, recently the Olympic Games have ______.

A.created goodwill between the nations

B.brought about only false national pride

C.hardly showed any international friendship

D.put an end to misunderstanding and hatred小题2:The underlined word “disallowed”(in Paragraph 2) means “______”.

A.permitted to pass

B.considered as reasonable

C.won by the other side

D.refused to accept小题3:What did the manager mean by saying, “Hockey and the International Hockey Federation 

are finished"?

A.His team would no longer take part in international games.

B.Hockey and the Federation are both ruined by the unfair decisions.

C.There should be no more Hockey matches organized by the Federation.

D.The Federation should break up.小题4:The author gives the example in paragraph 2 to show ______.

A.how false national pride led to undesirable incidents in international games

B.that sportsmen are often against the final decisions

C.that competitiveness in the games discourages international friendship

D.that unfair decisions are common in the Olympic Games小题5:What conclusion can be drawn from the passage?

A.The organization of the Olympic Games must be improved.

B.Athletes should compete as individuals in the Olympic Games.

C.A game should be played competitively rather than for the love of the game.

D.More and more athletes will compete for their own honor.

名词解释