The Auxiliary Devices Of A Method For Measuring Residual Stress Based On The Magnetic Measurement, Signal Producer And Data Analyzer

In many areas of the national economy, wide application of ferromagnetic materials, such as railroad tracks, pipelines, steel pressure vessels, steely bridges, et cetera. These facilities will have a direct impact on the safety of the normal operation of the national economy and people's property. Ferromagnetic components are usually damagedâ†'crack stress concentration (seam)â†'fault, the following three processes. This shows that the concentration of stress for the whole surveillance equipment maintenance plays a vital role.The remain stress is the stress with balance state in the object on which no extern stress imposes .In the making process of many kinds of mechanism and enginery the remain stress will engender inside the component .In fact the remain stress is impossible to avoid in the process of the component .all kinds of remain stress will engender in the machining such as drawing, extrusion, roll, emendation, cutting, chop, hammer and heat machining .In the process of using, the piled stress of the extern stress and the remain stress will make the component deformed and the redistribute of the remain stress ,then shorten the period of the normal use of the device, even bring grave accident. So the monitoring of the remainder stress is very significant.The researching of detection to the remainder stress comes from 1930s. Now there are several decades methods which can be separate to two kinds of mechanical detection and physical detection, or can be called scathing detection and non scathing detection .The theory of mechanical detection is to release the part on which the remain stress impose by using certain methods which is to separate or divide this section in part, and by measuring the distortion, get the value of the remain stress in flexibility mechanics. The benefit of this kind of methods has higher reliability and veracity, but its cost is to break the structure more or less, so it is limited in fact.Physical detection is one kind of non scathing detections, it utilize the relations between the physical characters and the stress of the structure, primarily includes X ray diffraction, magnetism detection on which many kinds of methods are based, ultrasonic detection.In both kinds of method, the X ray diffraction and the blind-hole detection have been delved deeply and been matured. But both kinds of these methods have their limitation, the blind-hole detection is a kind of devastating method, and the depth of the X ray diffraction is only 30um. When the ferromagnetism object is imposed by stress, its remote structure such as magnetic domain, magnetism conductance and magnetism resistance will be changed. This change will change the value of the voltage in the induction windings, so can get the value of the stress by measuring the value of the voltage, this is the theory of the magnetism detection. After a lot of experiments to prove that such residual stress measurement method is feasible. In this connection, we have the research and development of auxiliary equipment, including signal circuits. PC data acquisition circuit and the data analysis, this is the basic thesis of this work.[1] Since the low-frequency signal source by circuit simulation performance is not satisfactory, and the lower frequency output signal. So consider the use of single chip controller form for the completion of the interrupted output waveform data. Use the converter's output waveform needed. In this paper, the low-frequency signal generator is the core piece of the 8-bit MCU and DAC chip was DAC0832. The experiments show that this circuit with the signal frequency stability, rate stability, harmonic distortion small waveform good.[2] Data acquisition circuit 89S52 SCM as controller As with MAX197 12 of the A/D converter circuit. 89S52 SCM is primarily through of the provision of the MAX197.to completion of the data acquisition process control and data acquisition mode. MAX197 completed reading the register data transmission. MAX197 in different ways under the computer's control data acquisition, the data collected will be transmitted to the microprocessor.[3] Because of the limited capacity of SCM analysis of the data, using serial access PC for data analysis. The data acquisition system designed PC software is written in Microsoft Visual Basic 6.0 as a tool for development. The mostly of the software system is to implement PC serial port switch, remote data acquisition switch and the data reception and preservation.