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1.圆柱形角尺的修理 圆柱形角尺的修理需要在磨床上进行。在磨床上修角尺的外径和两端时,是以两端中心孔作为定位基准的。在修前应抛光或研磨中心孔,这道工序可在车床上进行。将死顶针装在车床主轴和尾座锥孔上,用尾崖顶针加研磨膏研磨中心孔,研好一端后调头研磨另一端中心孔。最后,在外圆磨床上修磨外径和两端面,采用超精磨加工,达到表面粗糙度的要求。在磨床上修角尺之前,应先将磨床调整好,以防将角尺外径磨成锥形,就是说不能把角尺外径磨成大小头,必须保证角尺外径和端面互成90°角。 2·刀口形角尺的修理 修刀口形角尺是将一组(三把)角… 相似文献
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Li K 《Applied optics》1995,34(28):6376-6379
A laser-based technique, referred to as interferometric strain rosettes for measuring three in-plane strains, is presented. The strain rosette consists of three microindentations produced on a specimen surface and can be of two separate forms. The two forms are 45° and 60° rosettes for indentations located at the vertices of a 45° right triangle and an equilateral triangle, respectively. The three indentations for either form can be grouped into three pairs. When the indentations are illuminated with laser light, each pair of indentations acts like a two-point source generating a pair of Young's interference fringe patterns. The fringe spacing is inversely proportional to the separation of the indentations. Because strains cause the separation to change, the fringe spacing also changes. The fringe change is monitored with linear-array diodes and collected real time through a microcomputer system. The three strain components in the directions of the indentation pairs can then be obtained. 相似文献
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Leslie Banks-Sills Yuval Freed Rami Eliasi Victor Fourman 《International Journal of Fracture》2006,141(1-2):195-210
Experiments are carried out to determine the delamination toughness for a crack along the interface between two transversely
isotropic materials. The material chosen for study consists of carbon fibers embedded within an epoxy matrix. A crack is introduced
between two layers of this material, with fibers in the upper layer along the + 45°-direction and those in the lower layer
along the − 45°-direction both with respect to the crack plane. The Brazilian disk specimen is employed in the testing. To
calibrate the specimens, stress intensity factors are obtained which result from the applied load, as well as residual curing
stresses. It may be noted that all three modes are coupled, leading to a three-dimensional problem. The finite element method
and a mechanical M-integral are employed to determine the stress intensity factors arising from the applied load. For the residual stresses,
a three-dimensional conservative thermal M-integral is presented for stress intensity factor determination. The stress intensity factors found for the applied load
and residual stresses are superposed to obtain a local energy release rate, together with two phase angles. From the load
at fracture, the critical interface energy release rate or interface toughness
as a function of phase angles ψ and ϕ is determined. Results are compared to a fracture criterion. 相似文献
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依据JJF1059-1999《测量不确定度评定与表示》要求,并综合测量设备、人员、环境条件等因素,对正弦规成30°时的角值误差的测量结果进行测量不确定度的分析和评定,并按照CNAS-CL07∶2011《测量不确定度要求》提出的CMC表示方式表示测量结果。 相似文献
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依据1059.1-2012《测量不确定度评定与表示》要求,对正弦规成30°时的角度偏差测量结果进行测量不确定度的分析和评定。 相似文献
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重庆水泵厂計量室,摸索到一种大型直角尺簡便修理方法。其特点是:工具簡便,容易掌握,效率較高,比較适用。現将这种方法介紹如下: 相似文献
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文章介绍的检验方法适用于边长达1 500mm的宽度角尺.方法规定了公称长度的精度范围、质量的性能及检验. 相似文献
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提出了一种改进输入形式的径向基网络RBFN与自回归隐马尔可夫模型ARHMM相结合的异常数据检测方法,并通过引入核空间概念,用以解决过程工业中大量过程数据要求在线异常检测问题。该方法利用改进的RBF网络在核空间内预测待检测数据值,并根据核空间内的预测值与实际值偏差的大小,利用核ARHMM检测数据异常情况。改进的RBF网络能够方便地引入遗忘因子以及惩罚因子,从而增加算法的鲁棒性,提高检测的准确性。采用核ARHMM检测算法可以直接对数据异常情况作出准确判断,从而避免事先确定检测阈值的问题。通过实验与应用证明了该算法的实用性,与AR模型检测方法比较,该方法更适合于过程数据的异常检测问题。 相似文献
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圆柱角尺是一种制造方便、精度高的专用量具,普遍用作光隙法检定直角尺的基准,但由于光隙法采用估计读数,存在很大误差,况且为避免直角尺侧角误差,给检定带来的影响,故仅局限于宽座直角尺的检定,使用范围很窄。我厂计量室利用圆柱角尺与装有杠杆千分表的一个精密圆环所组成的检具,用于检定 相似文献
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《计量技术》90年第12期刊载了《圆柱角尺垂直度的测量及其误差分析》(下称《测量》),文中介绍了对一米或更大的圆柱角尺的垂直度进行精确测量的方法。笔者认为该方法似有不妥之处,提出来与大家商榷。 1.《测量》中是用两标准心轴组成60°~90°的V型角度,被测圆柱角尺紧靠心轴测量,如图1所示。但实际上,圆柱角尺的圆度 相似文献
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电厂锅炉集箱小口径管座角焊缝大多采用非全焊透形式。制造厂一般进行磁粉检查,在役检查中,需要对管座角焊缝内部进行超声波检查。本文介绍了在实际探伤中,根据焊缝结构尺寸,选择合适的探头,采用直接接触法手工超声波检测方法,从而达到检测目的。 相似文献