濮良贵机械设计考研真题题库视频网课!
<p class="ne-p"><strong><span class="ne-text">濮良贵机械设计考研真题题库视频网课</span></strong><strong><span class="ne-text">!</span></strong><br></p><p class="ne-p"><strong><span class="ne-text">资料全称:</span></strong><strong><span class="ne-text">濮良贵《机械设计》(第10版)全套资料【笔记+题库+视频】</span></strong></p><p class="ne-p"><strong><span class="ne-text">濮良贵机械设计考研真题题库视频网课</span></strong><strong><span class="ne-text">部分摘录:</span></strong></p><p class="ne-p"><strong><span class="ne-text">填空题</span></strong></p><p class="ne-p"><strong><span class="ne-text">机械零件的设计准则为、、寿命准则、振稳定性准则和可靠性准则。[西北工业大学2015研]</span></strong></p><p class="ne-p"><span class="ne-text">【答案】强度准则;刚度准则</span></p><p class="ne-p"><span class="ne-text">【解析】本题考查机械零件的5个设计准则,其名称、具体内容、表达式均为考查重点,多以选择题和填空题的形式出现。</span></p><p class="ne-p"><strong><span class="ne-text">机械零件丧失预定功能或预定功能指标降低到许用值下的现象,称为机械零件的。[广东工业大学2014研]</span></strong></p><p class="ne-p"><span class="ne-text">【答案】失效</span></p><p class="ne-p"><span class="ne-text">【解析】本题考查失效的概念。机器失效将造成巨大的经济损失,在设计时必须对其产品,包括零、部件,进行可靠性分析与评估。机器可靠性的高低是用可靠度来衡量的。</span></p><p class="ne-p"><strong><span class="ne-text">下列四种叙述中正确的是()。[四川大学2013研]</span></strong></p><p class="ne-p"><span class="ne-text">A.变应力只能由变载荷产生</span></p><p class="ne-p"><span class="ne-text">B.静载荷不能产生变应力</span></p><p class="ne-p"><span class="ne-text">C.变应力是由静载荷产生的</span></p><p class="ne-p"><span class="ne-text">D.变应力是由变载荷产生的,也可能由静载荷产生</span></p><p class="ne-p"><span class="ne-text">【答案】D</span></p><p class="ne-p"><span class="ne-text">【解析】变载荷产生变应力,但变应力也可能由静载荷产生。故选D项。</span></p><p class="ne-p imgbox"><span class="image-box"><img data-original="http://image.uc.cn/s/wemedia/s/upload/2022/c5d7727b1192e4c20af4867fd14114ac.png" data-src="http://image.uc.cn/o/wemedia/s/upload/2022/c5d7727b1192e4c20af4867fd14114ac.png;,4,png;3,700x.png" src="//image.uc.cn/s/uae/g/1v/images/image-lazyload.png" uploaded="1" data-infoed="1" data-width="749" data-height="581" data-format="png" data-size="427488000" data-index="0" class="image-default-bg image-loaded b-lazy" style="width: 700px !important; height: 542.991px !important;" heavypress="http://image.uc.cn/o/wemedia/s/upload/2022/c5d7727b1192e4c20af4867fd14114ac.png;,4,png;3,700x.png"><span class="share-import-title"></span></span></p><p class="imgbox_desc"><span>濮良贵机械设计考研真题题库视频网课!</span></p><p class="ne-p"><strong><span class="ne-text">循环特性等于()时,称为对称循环变应力。[中山大学2018研]</span></strong></p><p class="ne-p"><span class="ne-text">A.-1</span></p><p class="ne-p"><span class="ne-text">B.1</span></p><p class="ne-p"><span class="ne-text">C.0</span></p><p class="ne-p"><span class="ne-text">D.无穷大</span></p><p class="ne-p"><span class="ne-text">【答案】A</span></p><p class="ne-p"><span class="ne-text">【解析】交变应力循环特性r等于最小应力与最大应力的比值。循环特性r=-1的变应力称为对称循环变应力;循环特性r=0的变应力称为脉动循环变应力;循环特性r=+1则表示材料所受的应力为静应力。</span></p><p class="ne-p"><strong><span class="ne-text">对于受循环变应力作用的零件,影响疲劳破坏的主要因素是()。[扬州大学2019研]</span></strong></p><p class="ne-p"><span class="ne-text">A.最大应力</span></p><p class="ne-p"><span class="ne-text">B.最小应力</span></p><p class="ne-p"><span class="ne-text">C.平均应力</span></p><p class="ne-p"><span class="ne-text">D.应力幅</span></p><p class="ne-p"><span class="ne-text">【答案】D</span></p><p class="ne-p"><span class="ne-text">【解析】对于受循环变应力作用的零件,最小应力不变的情况下,应力幅越小,零件的疲劳强度越高。</span></p><p class="ne-p"><strong><span class="ne-text">某截面形状一定的零件,当其尺寸增大时,其疲劳极限值将随之()。[中山大学2013研]</span></strong></p><p class="ne-p"><span class="ne-text">A.增高</span></p><p class="ne-p"><span class="ne-text">B.降低</span></p><p class="ne-p"><span class="ne-text">C.不变</span></p><p class="ne-p"><span class="ne-text">D.规律不定</span></p><p class="ne-p"><span class="ne-text">【答案】B</span></p><p class="ne-p"><span class="ne-text">【解析】零件的截面形状一定,当截面尺寸增大时,疲劳极限值将降低。因为截面积增大,累积缺陷会增多,疲劳极限值将会减小。</span></p><p class="ne-p"><strong><span class="ne-text">两轴线互相平行的圆桂体接触,受径向压力,则两零件的接触应力()。[中国科学院大学2013研]</span></strong></p><p class="ne-p"><span class="ne-text">A.相等</span></p><p class="ne-p"><span class="ne-text">B.不相等</span></p><p class="ne-p"><span class="ne-text">C.与直径相关,直径大的接触应力大</span></p><p class="ne-p"><span class="ne-text">【答案】A</span></p><p class="ne-p"><span class="ne-text">【解析】当两圆柱体相接触时,其最大接触应力正比于所加载荷的二分之一次方,两轴线互相平行时,在径向力作用下,两零件的接触应力相等。</span></p><p class="ne-p"><strong><span class="ne-text">温度升高时,润滑油的粘度()。[浙江大学2013]</span></strong></p><p class="ne-p"><span class="ne-text">A.升高</span></p><p class="ne-p"><span class="ne-text">B.减低</span></p><p class="ne-p"><span class="ne-text">C.不变</span></p><p class="ne-p"><span class="ne-text">D.可能升高也可能减低</span></p><p class="ne-p"><span class="ne-text">【答案】B</span></p><p class="ne-p"><span class="ne-text">【解析】润滑油的粘度随温度的升高而降低,随压强的增大而增加。</span></p><p class="ne-p imgbox"><span class="image-box"><img data-original="http://image.uc.cn/s/wemedia/s/upload/2022/a93e19e04da0ed753689631ab61d1794.png" data-src="http://image.uc.cn/o/wemedia/s/upload/2022/a93e19e04da0ed753689631ab61d1794.png;,4,png;3,700x.png" src="//image.uc.cn/s/uae/g/1v/images/image-lazyload.png" uploaded="1" data-infoed="1" data-width="755" data-height="583" data-format="png" data-size="456116000" data-index="1" class="image-default-bg b-lazy" heavypress="http://image.uc.cn/o/wemedia/s/upload/2022/a93e19e04da0ed753689631ab61d1794.png;,4,png;3,700x.png" style="width: 700px !important; height: 540.53px !important;"><span class="share-import-title"></span></span></p><p class="imgbox_desc"><span>濮良贵机械设计考研真题题库视频网课!</span></p><p class="ne-p"><strong><span class="ne-text">以下4顶特性中,只属于润滑脂的特性是()。[浙江大学2013研]</span></strong></p><p class="ne-p"><span class="ne-text">A.凝点</span></p><p class="ne-p"><span class="ne-text">B.滴点</span></p><p class="ne-p"><span class="ne-text">C.闪点</span></p><p class="ne-p"><span class="ne-text">D.油性</span></p><p class="ne-p"><span class="ne-text">【答案】B</span></p><p class="ne-p"><span class="ne-text">【解析】润滑脂的主要性能指标是锥入度和滴点。</span></p><p class="ne-p"><strong><span class="ne-text">齿轮胶合失效属于(),点蚀失效属于()。[中国科学院大学2013研]</span></strong></p><p class="ne-p"><span class="ne-text">A.粘附磨损B.磨粒磨损</span></p><p class="ne-p"><span class="ne-text">C.接触疲劳磨损</span></p><p class="ne-p"><span class="ne-text">D.冲蚀磨损</span></p><p class="ne-p"><span class="ne-text">E.机械化学磨损</span></p><p class="ne-p"><span class="ne-text">【答案】A;C</span></p><p class="ne-p"><span class="ne-text">【解析】粘附磨损是金属摩擦副之间最普遍的一种磨损形式,齿轮胶合实质就是齿面金属直接接触并相互粘着;接触疲劳磨损即指材料的最大应力超过材料相应的接触疲劳极限时,材料表面发生疲劳裂纹。这些裂纹继续扩展,相互连接,形成小片并脱落,在齿轮表面上出现细碎的凹坑或麻点,从而造成齿面损伤,称为疲劳点蚀。</span></p><p class="ne-p"><strong><span class="ne-text">在受预紧力的紧螺栓连接中,螺栓危险截面的应力状态为()。[浙江大学2012研]</span></strong></p><p class="ne-p"><span class="ne-text">A.纯扭剪</span></p><p class="ne-p"><span class="ne-text">B.简单拉伸</span></p><p class="ne-p"><span class="ne-text">C.弯扭组合</span></p><p class="ne-p"><span class="ne-text">D.拉扭组合</span></p><p class="ne-p"><span class="ne-text">【答案】D</span></p><p class="ne-p"><span class="ne-text">【解析】预紧力使螺纹受轴向拉力,拧紧时螺纹间的摩擦力矩使螺纹受扭矩,故应力状态是拉扭组合。</span></p><p class="ne-p"><span class="ne-text">......</span></p><p class="ne-p"><strong><span class="ne-text">>>>本文为节选>>>相关资料均载于攻关学习网>>>每年更新!</span></strong></p><br>最后别忘了到沪学网下载免费课程!
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