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1.
A proper detection and classification of defects in steel sheets in real time have become a requirement for manufacturing these products, largely used in many industrial sectors. However, computers used in the production line of small to medium size companies, in general, lack performance to attend real-time inspection with high processing demands. In this paper, a smart deep convolutional neural network for using in real-time surface inspection of steel rolling sheets is proposed. The architecture is based on the state-of-the-art SqueezeNet approach, which was originally developed for usage with autonomous vehicles. The main features of the proposed model are: small size and low computational burden. The model is 10 to 20 times smaller when compared to other networks designed for the same task, and more than 700 times smaller than general networks. Also, the number of floating-point operations for a prediction is about 50 times lower than the ones used for similar tasks. Despite its small size, the proposed model achieved near-perfect accuracy on a public dataset of 1800 images of six types of steel rolling defects. 相似文献
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针对含噪信号的有效奇异值个数难以确定的问题,提出了一种改进的奇异值分解降噪方法--奇异值累积法。该方法通过计算奇异值的实际下降值与奇异值平均下降速度累积量的差值,并取该差值最大值点的位置作为有效奇异值的分界点来确定有效奇异值的个数。在此基础上,提出了一种基于奇异值累积法与快速谱峭度的滚动轴承故障诊断方法。采用奇异值累积法对原信号进行降噪处理,然后利用快速谱峭度确定滤波器中心频率及带宽,通过分析频段包络谱中明显的频率成分来诊断故障。该方法可以有效去除信号中的噪声,使得到的峭度值所反映的故障冲击更接近实际情况。对含内圈、外圈故障的滚动轴承实验数据进行分析,实验结果表明,相比快速谱峭度的故障诊断方法,该方法具有更好的故障识别效果。 相似文献
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具有一定曲率外形的铝合金整体壁板属于典型的多筋零部件,传统弯曲成形工艺成形困难,容易产生多种缺陷。提出了离散填料辅助滚弯成形整体2A12T4铝合金壁板滚弯工艺,并通过实验与整体填料滚变成形进行了对比,同时采用有限元模拟技术,探究了离散填料辅助整体壁板滚弯成形中的影响因素。研究结果表明:填料数量、上下垫板厚度等因素对成形性能影响较大,填料在3~6块时成形稳定,可以有效地避免筋条屈曲与失稳;随垫板厚度增加,壁板表面圆弧更加光滑、连续,但是回弹性增强;上下垫板分别在10~20 mm厚度时,综合性能较好。通过离散填料辅助滚弯技术可以成形出质量较高的整体壁板。 相似文献
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针对轧机垂直系统动力学参数可信度不足等问题,提出一种基于实测数据的改进粒子群算法辨识轧机垂直系统动力学参数的方法。首先,将轧机垂直系统刚度和阻尼考虑成达芬振子和范德波尔振子,构建轧机垂直系统非线性动力学模型,并对粒子群算法进行改进;然后,通过数值仿真算例辨识得到系统在感染噪声和不含噪声时的动力学参数,验证了该算法的有效性;最后,以现场某轧机垂直系统为研究对象,基于现场实测数据,应用该算法进行辨识,得到了轧机垂直系统动力学参数估计,通过实测位移、速度和加速度信号分别与辨识后的位移、速度和加速度信号进行对比,证明该方法辨识轧机垂直系统动力学参数结果可靠,具有一定的工程应用价值。 相似文献
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《Journal of the European Ceramic Society》2019,39(2-3):624-630
Single phase PbHfO3 antiferroelectric ceramics were prepared via rolling process. It is revealed that the rolling process can reduce the grain size and increase the bulk density, which lead to the enhanced breakdown strength up to 268 kV/cm versus 219 kV/cm of samples using the conventional solid-state method. As a result, high recoverable energy density of 7.6 J/cm3 with an efficiency of 80.8 % was achieved. Meanwhile, a large current density of 1381 A/cm2 and an ultrahigh peak power density up to 170 MW/cm3 were observed under 250 kV/cm. In addition, unique electrical polarization response characteristics at different electric fields and temperature-induced structural phase transitions were also investigated. The energy storage performance and charge-discharge properties of PbHfO3 were first studied in this communication and all the results indicate that PbHfO3 ceramic is a promising candidate for pulse power applications. 相似文献
8.
In this research, deep consolidation technique is utilized for processing of low and high carbon content ferrous powders to manufacture composite material. High carbon content ferrous powders were used as reinforcing material. The powder particles were allowed to mix with low carbon content ferrous powders in 50:50 weight percent for fabrication of composites. The composites were heat treated at three different temperatures (i.e., 800°C, 900°C, and 1000°C). The changes in microstructure, microhardness, the grain size, and bonding among powder particles were studied. Refinement of grains was observed and this led to improved hardness enabling the processed material to be used as a suitable composite. Abrasive wear tests were carried out using a laboratory tribometer in dry reciprocating sliding contact against Sic abrasive paper. The outcomes demonstrate that the abrasive wear resistance was notably affected by the treatment temperature and hardness of the composites. 相似文献
9.
Darothi Bairagi Venkataramana Munukuti Pallabi Bhuyan Rajib Saha Sumantra Mandal 《工业材料与腐蚀》2021,72(5):829-838
The influence of cementite spheroidization on the impact toughness and electrochemical properties of a high-carbon steel has been thoroughly investigated in this study. Heavy warm rolling, followed by 2 h of annealing, has resulted in near-complete spheroidization, leading to a microstructure consisting of nano-cementite globules dispersed in the ultrafine-grained ferritic matrix. The Charpy impact test exhibited superior impact toughness with increased spheroidization. It is validated by the presence of abundant dimples in the fractographs of spheroidized specimens, in contrast to the as-received one that experienced a brittle failure due to its lamellar pearlitic structure. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) carried out in a 3.5% NaCl solution revealed that the corrosion resistance of the alloy gets improved with the increase in the degree of spheroidization. This is attributed to the lower susceptibility of the spheroidized specimen to microgalvanic corrosion owing to the minimum area of contact between nano-spheroidized cementite and ferrite, as elucidated with the help of EIS results aided by equivalent electrical circuit model. 相似文献
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