【摘要】 本文用光弹性实验的方法揭示了抓爪截面的应力分布规律,得出竖椭圆形、圆形和横椭圆形爪受力状态良好。木材抓具的抓爪,在不利工况下的危险截面是位于撑杆与抓爪联结爪耳处的内缘,该处所受应力最大。利用本试验所得的数据与公式,可以求出不同材料,不同截面尺寸的抓具允许收紧力,并以此可以进行横椭圆形爪的原木归装抓具的设计与计算。更多还原

【Abstract】 The paper indicates the regularity of stress distribution over the sections of log grips by means of photoelastical method. It is concluded that the grips of vertical elliptical, circular and horizontal elliptical contour are stressed favourably. Under unfavourable work conditions a dangerous section forms on the inner wing of the joint between sprag and grip, where the stresses are concentrated. It is possible to determine the allowable gripping strenth of the grips made of various materials and of various section sizes, and furthermore, to design the gripping device with horizontal elliptical grips, using the data and formulae derived from the experiment.更多还原