高职机械设计基础螺纹连接与螺旋传动.ppt

第7章 螺纹连接 7-1 螺纹连接的基本类型及标准件连接 7-2 螺纹连接的拧紧与防松 7-3 螺纹的强度计算 7-4 螺栓组的连接设计和受力分析 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 本章要求: 1.了解螺纹连接的主要类型及螺纹连接件。 2.掌握螺栓强度计算方法，会查阅国家标准。 3.理解螺栓的拧紧与防松的概念。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 罗定职业技术学院 连接：将两个或两个以上的零件连成一体的结构。 常见的机械连接有两类： （1）机械动连接（动连接）：被连接的各零部件之间 可以有相对位置变化，如运动副； （2）机械静连接（静连接）：被连接的各零部件间的 相对位置固定不变，不允许产生相对运动。 静连接静连接 不可拆连接 装拆方便，装拆不损伤连接 中的任何零件。如螺纹连 接、键连接、销连接 在拆开连接时会损坏连接 中的零件或使用性能。如 焊接、铆接、黏接 可拆连接 （永久连接） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 7-1 螺纹连接的基本类型及标准件连接 螺纹连接是利用具有螺纹的零件构成的一 种可拆卸连接，基本要求是不断（具有足够 的强度）、不松（连接可靠）。 一、螺纹连接的基本类型 （1）螺栓连接 （2）双头螺柱连接 （3）螺钉连接 （4）紧定螺钉连接 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. （1）螺栓连接 栓连接 连 连 连 连 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. （2）双头螺柱连接 连 连 连 连 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. （3）螺钉连接 连 连 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. （4）紧定螺钉连接 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 吊环螺钉 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 地脚螺栓 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 1.螺栓、螺柱、螺钉连接件 二、标准螺纹连接件 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 2.紧定螺钉、螺母 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 3.垫圈 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 罗定职业技术学院 7-2 螺纹连接的拧紧与防松 一、螺纹连接的拧紧 绝大多数螺纹连接在装配时需要拧紧，使连接在 承受工作载荷之前，预先受到力的作用，这个预加的作 用力称为预紧力。 一般螺纹连接在装配的时候都必须拧紧，以增强连 接的可靠性、紧密性和防松能力。 对于一般连接，可凭经验来控制预紧力的大小，但 对于重要的连接就要严格控制其预紧力。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 连接中常用的单线普通螺纹和管螺纹在冲击、振动、变载 荷下或温度变化过大时容易产生松脱现象。 螺纹连接防松的根本问题在于要防止螺旋副的相对运动 。 常用的防松方法: （1）摩擦防松 （2）机械防松: （3）铆冲防松：端铆、冲头 弹簧垫圈对顶螺母 自锁螺母 开口销与槽形螺母止动垫片 二、螺纹连接的防松 串联钢丝 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 7-3 螺栓的强度计算 螺栓的强度是指连接螺栓中承受最大载荷的单个螺栓的强 度。 1. 螺栓传递的载荷主要有两类： （1）轴向载荷：外载荷沿螺栓轴线方向，即受拉螺栓。 （2）横向载荷：外载荷垂直于螺栓轴线方向。 采用普通螺栓，靠预紧力使被连接件接合面间产生的摩擦力 传递横向载荷，此时螺栓所受的是预紧力，为轴向拉力。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 绞制孔用螺栓，螺杆与绞制孔间是过渡配合，工作时靠螺 杆受剪，杆壁与孔相互挤压传递横向载荷，此时杆件受剪 切力作用，故称受剪螺栓。 2.螺纹连接的主要失效形式有三类： （1）拉断； （ 2）剪断； （3）对于铰制孔连接出现孔或螺栓挤压变形。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 一、普通螺栓的强度计算 （1）受拉螺栓常见的失效形式多为螺纹的塑性 变形和断裂。实践表明，螺栓断裂多发生 在开始传力的第一、第二圈旋合螺纹的牙 根处，因应力集中较大。 （2）一般选用标准螺纹零件，其主要尺寸已作 出规定，故螺栓的强度计算主要是求出或 校核螺纹危险剖面的尺寸，即螺纹小径d1。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 罗定职业技术学院 1.松螺栓连接的强度计算 工作时不需要将螺母拧紧。如吊钩 螺栓。 螺栓所受拉力=工作载荷 d1螺纹小径（mm）； F螺栓承受的轴向工作载荷（N）。 松螺栓连接的拉应力： 松螺栓连接的拉应力（N/mm2） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 2.紧螺栓连接的强度计算 （1）只受预紧力作用的螺栓。螺纹部分强度条件为 F螺栓承受的预紧力（N）； d1螺纹小径（mm）； 紧螺栓连接的拉应力（N/mm2） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 （2）受预紧力和轴向静工作拉力的螺栓连接。 F0总拉力； F预紧力； F工作拉力； F”螺栓受载变形后的剩余预紧力，大于零； 螺栓的相对刚度。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 螺栓相对刚度，其大小和连接的材料、结构形 式、尺寸大小及载荷作用方式等有关。一般设计时钢 制被连接件可取：金属垫（或无垫）0.20.3、皮革 垫0.7、铜皮石棉垫0.8、橡胶垫0.9；一般当工作拉 力F无变化时，螺栓受载变形后的剩余预紧力F”= （0.2 0.6）F，当F有变化时， F”=（0.6 1.0） F；对要求紧密性的螺栓连接，取F”=（1.5 1.8） F。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 罗定职业技术学院 若螺栓工作时被补充拧紧，在螺纹部分产生扭转 剪应力，将总拉力F0增大30%作为计算载荷，则受拉 螺栓螺纹部分的强度条件为 或 F0总拉力； d1螺纹小径（mm） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 二、绞制孔用螺栓连接的强度计算 这种连接是将螺栓穿过被连接件上的绞制孔并与 之过渡配合。在被连接件的接合面处螺栓杆受剪切， 螺栓杆表面与孔壁之间受挤压。因此，应分别按挤压 强度和抗剪强度计算。 （1）螺栓杆与孔壁的挤压强度 条件为 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 （2）螺栓杆的抗剪强度条件为 Fs单个螺栓所受的横向工作载荷（N）； Lmin螺栓杆与孔壁挤压面的最小高度（mm）; d0螺栓剪切面的直径（mm）; m螺栓受剪面数； :螺栓或孔壁材料中较弱者的许用挤压应力（N/mm2） ：螺栓材料的许用切应力（N/mm2） Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 7-4 螺栓组的连接设计和受力分析 一、螺栓组连接的结构设计 （1）接合面设计成轴 对称的几何形 状，使接合面受 力均匀。 （2）螺栓均匀布置， 远离螺栓组的几何中 心。圆周上的螺栓数 宜采用3、4、6、 8、12等，便于加工 时分度、画线。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 连接 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 （3）螺栓的布置应有合理的间距、边距和扳手空间。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 （4）应保证螺栓与螺母的支承面平整，并与螺栓轴 线垂直，以避免引起偏心载荷。一般可将被连接 件的支承表面制成凸台或沉头座。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. 机电工程系 模具教研室 罗定职业技术学院 二、螺栓组的受力分析 受力分析的目的是找出受力最大的螺栓，求其所 受力的大小和方向，利用公式校核螺栓强度或求出 螺栓直径，确定螺栓尺寸。螺栓组的其余螺栓可按 受力最大螺栓的直径选取。分析时有4点假设: （1）被连接件不变形； （2）各螺栓材料、尺寸和拧紧力均相同； （3）受力后材料变形（应变）在弹性范围内； （4）接合面型心与螺栓组型心重合，受力后接合面 仍为平面。 Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profile .Created with Aspose.Slides for .NET 3.5 Client Profile . Copyright 2004-2011 Aspose Pty Ltd.Copyright 2004-2011 Aspose Pty Ltd. Evaluation only.Evaluation only. Created with Aspose.Slides for .NET 3.5 Client Profi