(合力 3、连接处破坏的三种形式: ①剪切破坏 沿铆钉的剪切面剪断,如 P 沿nn面剪断。 (合力) ②挤压破坏 剪切面 铆钉与钢板在相互接触面 O 上因挤压而使溃压连接松动, n P 发生破坏。 ③拉伸破坏 钢板在受铆钉孔削弱的截面处,应力增大,易在连接处拉断
n n （合力） （合力） P P 3、连接处破坏的三种形式： ①剪切破坏 沿铆钉的剪切面剪断，如 沿n– n面剪断 。 ②挤压破坏 铆钉与钢板在相互接触面 上因挤压而使溃压连接松动， 发生破坏。 ③拉伸破坏 P n n Q 剪切面 钢板在受铆钉孔削弱的截面处，应力增大，易在连接处拉断
SHEAR 2 Practical calculation of shear Method of the practical calculation: According to possibility of breakage of the member some assumptions by which basic characteristic subjected to force actions can be reflected and calculations can be simplified are used. Then calculate its nominal stress, determine the corresponding permissible stress in accordance with the result of direct test. At last do the strength calculation applying range: volume of the member is not large and real stress is quite complex Such as the connecting pieces etc Assumption of practical calculation Assume that shearing stress is distributed uniformly in the shearing plane and equal to the average shearing stress
2、Practical calculation of shear Method of the practical calculation：According to possibility of breakage of the member some assumptions by which basic characteristic subjected to force actions can be reflected and calculations can be simplified are used. Then calculate its nominal stress, determine the corresponding permissible stress in accordance with the result of direct test. At last do the strength calculation. Applying range：volume of the member is not large and real stress is quite complex. Such as the connecting pieces etc. Assumption of practical calculation：Assume that shearing stress is distributed uniformly in the shearing plane and equal to the average shearing stress
二、剪切的实用计算 实用计算方法:根据构件的破坏可能性,采用能反映受力基本 特征,并简化计算的假设,计算其名义应力,然后根据直接试 验的结果,确定其相应的许用应力,以进行强度计算。 适用:构件体积不大,真实应力相当复杂情况,如连接件等。 实用计算假设:假设剪应力在整个剪切面上均匀分布,等于剪 切面上的平均应力
二、剪切的实用计算 实用计算方法：根据构件的破坏可能性，采用能反映受力基本 特征，并简化计算的假设，计算其名义应力，然后根据直接试 验的结果，确定其相应的许用应力，以进行强度计算。 适用：构件体积不大，真实应力相当复杂情况，如连接件等。 实用计算假设：假设剪应力在整个剪切面上均匀分布，等于剪 切面上的平均应力
SHEAR 1)Shearing plane-A: Shifting plane (Resultant Shearing force-Q: Internal force on the shearing plane. n P 2)Nominal shearing force--t ( Resultant Q O Shearing Q plane 3)Strength condition of shear n n ≤[], where[z Working stress should not exceed the permissible stress
1)Shearing plane--AQ ： Shifting plane. Shearing force--Q：Internal force on the shearing plane. AQ Q = 2)Nominal shearing force--： 3)Strength condition of shear： = AQ Q n jx = n n （ Resultant ） (Resultant ） P P P n n Q Shearing plane Working stress should not exceed the permissible stress. ,where
(合力 1、剪切面-4o:错动面。 P 剪力-Q:剪切面上的内力。 n 2、名义剪应力-c: (合力) Q 剪切面 Q 3、剪切强度条件(准则): n n r=%团]其[= 工作应力不得超过材料的许用应力
1、剪切面--AQ ： 错动面。 剪力--Q： 剪切面上的内力。 AQ Q = 2、名义剪应力--： 3、剪切强度条件（准则）： = A Q n jx 其中: = n n （合力） （合力） P P P n n Q 剪切面 工作应力不得超过材料的许用应力