Method and apparatus for simultaneous determination of post-buckling deformation parameters and elastic moduli of elastomeric material

Abstract

The invention discloses a method and an apparatus for simultaneous determination of post-buckling deformation parameters and elastic moduli of an elastomeric material. The method is as follows: a PLC controller controls a linear stepping motor through a driver, a movable supporting baffle plate is pushed by the linear stepping motor so as to allow a sample to undergo post-buckling deformation, a scanner acquires a post-buckling deformation image of the sample and transfers the image to a notebook computer, and image processing analysis software is used to process the sample so as to obtain the skeleton of the post-buckling deformation image; a coordinate of a point at a leftmost end of the sample and a coordinate of a point at a rightmost end of the sample are determined according to the skeleton of the post-buckling deformation image, a coordinate of the midpoint of chord length between the leftmost end point coordinate and the rightmost end point coordinate is calculated, and then flexibility of the midpoint, corners at the ends and elastic moduli are calculated. According to the invention, synchronous determination of the elastic moduli in a pressure bar post-buckling method and the post-buckling deformation parameters of the pressure bar are realized, which enables the processes of determination and calculation of the elastic moduli to be simplified; test operation is simple, determination precision is improved, and miniaturization, intelligentization and automation of the apparatus are realized.

Description

technical field [0001] The invention belongs to the field of physical property detection of engineering materials, and relates to a method and a comprehensive device for simultaneously measuring the post-buckling deformation behavior parameters and elastic modulus of elastic material compression rods, in particular to the axial displacement of the post-buckling ends of elastic material compression rods, the middle Method and device for simultaneous determination of point deflection, end rotation angle and elastic modulus. Background technique [0002] The analysis and calculation of post-buckling and large deflection mechanical properties of compression bars is the key technology in the process of developing some special parts in engineering. In the geometric nonlinear analysis of slender compression bars, the model can be simplified under certain assumptions, and the analysis results can be very good. It satisfies engineering requirements well and provides theoretical suppo...

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Problems solved by technology

[0003] Liang Jun (Food Science and Technology, 1991, (1): 28) developed a simple noodle bending broken strip detector for measuring the midpoint deflection and end axial displacement of noodle post-buckling by using a horizontal ruler and a vertical ruler. Visual measurement, low precision, inconvenient operation

In "Engineering Mechanics (1)" (P340-342) published by Higher Education Press, edited by Fan Qinshan in 2002, the post-buckling deformation parameters of slender compression rods were measured using a special special loader and a contact potentiometer, but the sample size Large size, special special loading machine is required, the size of the loading machine is very large, the structure is complex, and the midpoint deflection is measured by contact measurement, the measurement accuracy is low, only suitable for large-sized samples, not suitable for small-sized samples

[0004] At present, the Chinese patent number is ZL200810243157.1, titled "Measurement method and measuring instrument for bending and fracture rate of dried noodles based on axial compression". The midpoint deflection and end rotation angle are still measured visually through the ruler and angle scale line, the measurement accuracy is low and the operation is inconvenient

The Chinese patent number is ZL200910030016.6, titled "Measurement Method for Elastic Modulus of Dried Noodles Based on Post-buckling of Compression Bars", which is a method for measuring the elastic modulus of dried noodles based on post-buckling of compression bars by using a general physical property instrument, but does not involve the deformation parameters of dried noodles Measurement

The Chinese patent number is ZL200920231756.1, and the name is "Intelligent Measuring Instrument for Noodle Bending and Fracture Rate Based on End Axial Displacement". It uses touch screen technology, stepping linear motor drive technology and The PLC control technology has improved the bending resistance of dried noodles measured by the axial displacement of the end instead of the end rotation angle, as well as the input and output of the parameters of the measuring instrument, the transmission method and the control method of the axial displacement of the end, etc., but Unable to determine the elastic modulus of the sample and analyze the post-buckling deformation parameters of the sample

Therefore, there is no literature report on the method of measuring the mid-point deflection and end rotation angle of elastic material post-buckling deformation parameters by image processing method, and simultaneously measuring the elastic modulus.

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