问题 问答题 简答题

摆式转向架是怎样实现横向两级弹簧刚度的?

答案

参考答案:侧架横向位移分为两个阶段。

第一阶段可称为低阻力保护阶段,此阶段转向架的横向刚度值为侧架横向等效刚度与二系悬挂横向刚度的串联刚度;

第二阶段可称为对完全压实侧向冲击的高阻力保护阶段,此阶段转向架的横向刚度值为二系悬挂的横向刚度。因此,侧架摇摆式转向架利用弹簧托板,横向止挡使其横向悬挂特性形成类似的多级刚度。

阅读理解

One day, many years ago, when I was working as a psychologist in England, I brought David into my office. His face was pale and he looked at his own feet.

David lost his father when he was two years old and lived with his mother and grandfather ever since. But when he was 13, his grandfather died and his mother was killed in a car accident. His teacher told me that he refused to talk to others from then on.

David didn’t say a word. As he was leaving, I put my hand on his shoulder. “Come back next week if you like.” I said.

He came and I suggested we play a game of chess. He agreed. After that we played chess every Wednesday afternoon — in complete silence. Usually, he arrived earlier than we agreed. It seemed that he liked to be with me.

Maybe I gave David something. But I learned more from him. I learned that time makes it possible to get over what seems to be painful. David showed me how to help people like him.

根据短文内容,选择正确答案。

小题1:When David came into the writer’s office, he___________.

A. said hello to the writer   B. seemed happy    C. looked at his feet

小题2:David’s father died when he was ____________.  

A. 13        B. 2         C. 5

小题3:To help David, the writer ________ every Wednesday afternoon.

A. played chess with him     B. told stories to him    C. played soccer with him

小题4:What club did David join?

A. A chess club    B. An art club     C. A bicycle club

小题5:Which of the following statements is NOT true?

A. Since his father died, David refused to talk to others.

B. David didn’t say anything to the writer at first.

C. David finally got friends in school.

单项选择题