JPH02141643A - Mechanical property measuring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION 1. Field of Industrial Application This invention relates to a measuring device for measuring mechanical properties such as rigidity of a substance.

[Prior Art] Mechanical property measuring devices are generally classified into static measuring devices and dynamic measuring devices. An example of a conventional static measuring device is a tensile tester. A tensile testing machine applies a tensile load to a measurement sample to generate strain, and determines the mechanical properties of the measurement sample, such as the longitudinal elastic modulus, from the relationship drawn between the generated strain and the applied load.

On the other hand, as a dynamic measuring device, for example, there is a measuring device using a resonant frequency. This measuring device applies vibration to a measurement sample, detects its resonant frequency, and determines similar mechanical properties of the measurement sample based on the resonance frequency.

[Problems to be Solved by the Invention] However, in the conventional apparatus described above, there are restrictions on the size and shape of the measurement sample, and various problems have occurred.

First, in a tensile tester or a measurement device using a resonance frequency, the measurement principle of detecting strain occurring in a measurement sample or inducing resonance in a measurement sample is important. I had to prepare something with a linear shape.

In reality, the measurement sample is several millimeters (for example, 5M to 10M).
It is often the case that only small pieces of material of size m) are available, and measurements using such small pieces are extremely difficult with conventional equipment.

Second, with conventional devices, when measuring at a constant temperature, which is one of the measurement conditions, it is difficult to make the temperature distribution the same because the measurement sample is large and has a rod-like or linear shape. There was a problem in that it was not easy and difficult to make precise measurements. In particular, when measuring under high temperature conditions, it is difficult to make the temperature distribution of the measurement sample uniform, partly because the difference from the ambient temperature is large. In addition, under high-temperature conditions, the elastic limit of the sample to be measured decreases and creep may occur, making it difficult to measure accurately using a device that detects large strains such as a tensile tester.

The mechanical property measuring device of the present invention aims to solve the above-mentioned problems and to make this type of measurement accurate and easy.

Moxibustion Dish Erritan [Means for Solving the Problems] As illustrated in FIG. 1, the mechanical property measuring device of the present invention includes an ultrasonic transmitter and a receiver, and an ultrasonic probe M1 that is attached to the buffer section that propagates the ultrasonic waves and is brought into contact with the measurement sample S; and propagation of the ultrasonic waves between the transmitting section and the receiving section in the ultrasonic probe M1. an in-sample propagation time calculation means M2 that calculates the propagation time of the ultrasonic wave in the measurement sample S based on time; the propagation time of the ultrasonic wave in the measurement sample S and the thickness of the measurement sample in the ultrasonic propagation direction; sample propagation velocity calculation means M for calculating the propagation velocity of the ultrasonic wave within the measurement sample S from D;
3, the propagation velocity of the ultrasonic wave within the measurement sample S and the measurement sample S
The apparatus further comprises a mechanical property calculation means M4 for calculating various mechanical properties such as the rigidity of the measurement sample S based on the density of the measurement sample S.

[Operation J] The mechanical property measuring device of the present invention having the above configuration performs measurement by bringing the ultrasonic probe M1 into contact with the measurement sample S. At this time, the ultrasonic waves transmitted from the transmitting section of the ultrasonic probe M1 propagate into the measurement sample S via the buffer section. The propagated ultrasonic waves pass through or are reflected within the measurement sample S, and reach the receiving section of the ultrasonic probe M1 via the buffer section. The intra-sample propagation time calculation means M2 calculates the propagation time of the ultrasonic wave within the measurement sample S based on the propagation time between the ultrasonic transmitter and the receiver,
The sample propagation velocity calculating means M3 calculates the propagation velocity within the measurement sample S from the propagation time and thickness of the ultrasonic wave within the measurement sample S. The mechanical property calculation means M4 calculates mechanical properties such as the rigidity modulus based on the sample propagation velocity of the ultrasonic waves and the density of the measurement sample S determined in this way. Calculations for determining mechanical properties are performed, for example, using the following equations.

Rigidity modulus G So Bulk elastic modulus K ... (2) Longitudinal elastic modulus E [K≦Ff/s 2 ko ・ (3) Polyson ratio ν In the formula, CP is the propagation velocity of the longitudinal ultrasonic wave, and C3 is the transverse wave ultrasonic wave. The propagation velocity of the sound wave, ρCK'j/mm31, is the density of the measurement sample,
CI [謔/S2] is gravitational acceleration.

The above equations (1) to 4) are the equation of propagation velocity when longitudinal and/or transverse sound waves propagate through a solid that can be considered infinitely wide, and the relational equation between mechanical properties such as rigidity. It is derived from

The formulas are shown below.

Longitudinal wave ultrasonic propagation velocity CP Transverse wave ultrasonic propagation velocity C3 Poisson's ratio, which is the ratio of transverse strain to longitudinal strain ν = E-2
G = 3 - E = 3 - 2G2G 6K 2
(3 to 10 G) (7) [Example] In order to further clarify the structure and operation of the present invention described above, preferred embodiments of the present invention will be described next. Second
The figure is a schematic configuration diagram of a mechanical property measuring device according to an example.

As shown in the figure, this mechanical property measuring device includes an ultrasonic probe 1 that transmits and receives ultrasonic waves, an ultrasonic transceiver 2 that controls the transmitted waves and detects the received waves, and performs various calculations based on the transmitted and received waves. The apparatus is comprised of a computer 3 for performing this, a thickness measuring device 5 for measuring the thickness of the sample S to be measured, and an electric furnace 6 in which the sample S to be measured is placed and maintained at a predetermined temperature.

The ultrasonic probe 1 includes a longitudinal wave transducer 11 and a transverse wave transducer 1.
3 and a buffer section 15 to which these are attached. The longitudinal wave transducer 11 and the transverse wave transducer 13 of the embodiment serve as an ultrasonic transmitting section and a receiving section, respectively, and are arranged in parallel at one end of the buffer section 15. The ultrasonic transmission frequency is 10 [MH2] for the longitudinal wave transducer 11 and 5 [MH2] for the transverse wave transducer 13.
], the diameters of each vibrator 11.13 are both 6.35 [#]. It is preferable that the transmission frequency, diameter, and thickness of each of these vibrators 11, 13 are changed depending on the thickness of the measurement sample and the desired resolution. The higher the transmission frequency, the better the resolution of the measurement device will generally be. Furthermore, if the diameter and thickness of the transducer are increased, the transmitted power of the ultrasonic wave will be increased, so even a thick sample can be measured satisfactorily. Note that the transverse wave transducer 13 is capable of transmitting transverse ultrasonic waves in a direction perpendicular to its vibration surface. In addition to this, a longitudinal wave vibrator may be used as the transverse wave vibrator 13 in an inclined arrangement. In this case, the transverse ultrasound waves are generated from oblique longitudinal ultrasound waves.

The buffer section 15 is made of water glass, quartz, magnesium, nickel, etc., which are effective as a medium for ultrasonic waves, and its tip surface is finished with high smoothness as a contact surface 15a with the measurement sample S. Therefore, the ultrasonic waves from the ultrasonic transducers 11.15 efficiently enter the measurement sample S.

The ultrasonic transmitting/receiving device 2 controls the ultrasonic transmission of the longitudinal wave and transverse wave transducers 11.13 of the ultrasonic probe 1, and detects the ultrasonic waves received by both transducers 11.13.

The computer 3 includes input/output devices such as a CRT display 31 and a keyboard 33, and an electronic control device 35. The electronic control device 35 includes a well-known CPU 37 and a ROM 3.
9. Constructed as an arithmetic and logic operation circuit centering on RAM 41, etc., video RAM 43, input/output board 45 for the above input/output equipment, and measuring device input/output for ultrasonic transmitting/receiving device 2 and thickness measuring device 5. Equipped with 47 boats. This electronic control device 35 functions as an intra-sample propagation time calculation means, an intra-sample propagation velocity calculation means, and a mechanical property calculation means by executing a predetermined procedure stored in the ROM 39.

The thickness measuring device 5 includes a light emitting/receiving sensor 51 that emits an inspection light having a predetermined inclination angle and receives the reflected light, and measures the height of the top surface of the object to be measured and the height of the reference surface on which the object to be measured is placed. The height difference is output as the thickness of the measured object.

The electric furnace 6 has a measurement sample S placed therein, and is heated to and maintained at a predetermined temperature by a heater 61.
The ceiling is provided with an opening 63 having approximately the same size as the cross section of the buffer section 15 of the ultrasonic probe 1. This electric furnace 6 has, as a temperature control mechanism, a temperature indicator controller 65 that compares the temperature instruction setting with the set instruction temperature and the actual temperature, and a thermometer 6 positioned at approximately the same height as the measurement sample S in the furnace.
7, and a heater power supply controller 69 that adjusts the heating of the heater 61 based on the output of the temperature indication controller 65.

Measurement by the mechanical property measuring device configured as described above will be explained along the flowchart of FIG. 3. The temperature of the measurement sample S was raised to the temperature of the measurement conditions using the electric furnace 6 and held there. and measure the thickness of the measurement sample S under temperature conditions (step 100).
.

Next, the buffer part 15 of the ultrasonic probe 1 is attached to the electric furnace opening/closing port 63.
, and its contact surface 15a is brought into contact with the upper surface of the measurement sample S. After this, under the control of the ultrasonic transceiver 2, the longitudinal and transverse wave transducers 11 and 13 of the ultrasonic transducer 1 are
The ultrasonic wave is then transmitted (step 110). In the embodiment device, as shown in the explanatory diagram of FIG.
A part W1 of the ultrasonic wave W transmitted from 3 is reflected at the interface between the buffer section] 5 and the upper surface of the measurement sample S, travels backward through the buffer section 15, and propagates to each of the transducers 11 and 13.

On the other hand, the ultrasonic wave W2 incident on the measurement sample S is reflected at the interface between the bottom surface of the measurement sample S and the table surface, travels back and forth through the measurement sample S, and travels backward through the buffer section 15 to each transducer 1.
1.13.

FIG. 5 shows an example of pulses detected by the ultrasonic transceiver @2. The horizontal axis represents time, and the vertical axis represents pulse size. The ultrasonic transmitter/receiver 2 determines the propagation time T1 required for the reflected wave W1 from the top surface of the measurement sample to reach each transducer 11. The propagation time T2 required to reach '13 is measured (step 120).

The electronic control unit 35 of the computer 3 performs various calculations based on the propagation time T1 of the reflected wave W1 on the top surface of the measurement sample and the propagation time T2 of the inverse q:i wave W2 on the bottom surface of the measurement sample (step 130). In the example, the reflected wave W1 from the upper surface of the measurement sample
and the reflected wave W2 from the bottom surface of the measurement sample both reciprocate through the buffer section 15, so both reflected waves W1. The difference between the propagation times TI and T2 of W2 is determined as the sample round-trip propagation time of the ultrasonic wave. The intra-sample propagation velocity of the ultrasonic wave is calculated from this sample-like round trip propagation time and the thickness of the measurement sample S, and the obtained intra-sample propagation velocity and the density of the measurement sample S are calculated using equation (1) in the [action] section. .

By substituting into (2), (3), and (4), the rigidity modulus, bulk elastic modulus, longitudinal elastic modulus, and Poisson's ratio of the measurement sample S are calculated and output.

The measurement results of this example device are shown in Tables 1 to 3. Table 1 shows the contents of the measurement sample, Table 2 shows the calculation details of the propagation velocity in the sample of longitudinal waves and transverse ultrasonic waves, and Table 3 shows the results of the determined mechanical properties. In the right column of Table 3, for comparison, the longitudinal elastic modulus determined by a conventional measuring device using a resonant frequency is listed.

It can be seen that the longitudinal elastic modulus determined by the example device agrees well with this. Note that the measurements were performed at room temperature.

The mechanical property measuring device of the embodiment described above measures the mechanical properties of the measurement sample S by determining the propagation velocity of longitudinal waves and transverse ultrasonic waves within the measurement sample S. It is possible to measure any size or shape. Moreover, since the measurement is carried out by bringing the ultrasonic probe 1 into contact with the measurement sample S, it can be carried out easily and in a short time.

Furthermore, when performing measurements under high temperature conditions, the measurement sample can be made small, making it easier to make the temperature distribution uniform, and the measurement accuracy is extremely high. During this measurement, each vibrator 11.13 of the ultrasonic probe 1 is separated from the inside of the furnace by the buffer section 15, so the temperature is within the appropriate operating temperature range (up to 5
0'C). Therefore, according to the apparatus of the embodiment, it is possible to set temperature conditions from a very wide range from room temperature to high temperature (approximately 1000° C.) and measure the mechanical properties of the measurement sample under those conditions. Note that even if the temperature is 1000''C or higher, measurement can be carried out depending on the heat resistance of the buffer section 15. Measurement can also be carried out under low-temperature or extremely low-temperature conditions.

Furthermore, since measurements can be carried out using longitudinal and transverse ultrasound waves, all of the stiffness modulus, bulk modulus, longitudinal elastic modulus, and Poisson's ratio can be obtained.

In addition to the above-mentioned effects, the device of this embodiment has the transmitting section and the receiving section of the ultrasonic probe 1 integrated into one ultrasonic transducer 11 (13).
Since it has a structure in which both functions are used, the following effects are achieved. At the time of measurement, it is only necessary to bring the ultrasonic probe 1 into contact with one point of the measurement sample, and the measurement can be carried out easily. Further, this contact operation of the ultrasonic probe 1 is not affected by the thickness of the measurement sample S, and its simplicity remains the same. Furthermore, in the arithmetic processing of the computer 3, the propagation time in the buffer section 15 included in the propagation time T1 of the reflected wave M1 on the top surface of the measurement sample and the propagation time T2 of the reflected wave M2 on the bottom surface of the measurement sample is determined by the propagation time of both reflected waves M1. Can be canceled by finding the difference between the propagation times TI and T2 of M2, and both reflected waves M1
．． The difference between the propagation times T1 and T2 of M2 can be directly used as the reciprocal propagation time of the ultrasonic wave within the sample.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. It goes without saying that the invention can be implemented in various ways without departing from the gist of the invention.

Effects of the Invention As detailed above, the mechanical property measuring device of the present invention has the following effects:
The method calculates the propagation velocity of the ultrasonic wave within the measurement sample and calculates the mechanical properties of the rigidity of the measurement sample based on this sample propagation velocity, so it can be measured regardless of the size or dimensions of the measurement sample. It has excellent effects. For example, only 5on to 10M, which was difficult to measure in the past.
Even a piece of material with zero angle can be easily measured.

The measurement operation is simply to bring the ultrasonic probe into contact with the sample to be measured, and the measurement can be carried out easily and in a short time.

Furthermore, even when measuring a measurement sample under its operating temperature conditions, since the measurement sample can be made small and the temperature distribution can be easily made uniform, accurate measurement can be achieved from low to high temperatures. In particular, the ultrasonic transmitter and receiver of the ultrasonic probe of the device of the present invention are separated from the measurement environment by the buffer section and protected, so that the device is effective for measurements under all environmental conditions in addition to temperature conditions.

Furthermore, in the present invention, the device configured to measure using both longitudinal and transverse ultrasonic waves can measure various mechanical properties such as rigidity modulus, bulk modulus, longitudinal elastic modulus, and Poisson's ratio all at once. It has the excellent effect of being able to

[Brief explanation of the drawing]

Figure 1 is a block diagram illustrating the basic configuration of the present invention, Figure 2 is a schematic configuration diagram of a mechanical property measuring device as an embodiment of the present invention, and Figure 3) A flowchart showing the measurement process, FIG. 4 is an explanatory diagram of the ultrasonic propagation path in the example device, and FIG.
2 is a timing chart showing an example of detection of ultrasonic waves. 1... Ultrasonic probe 2... Ultrasonic transmitting/receiving device 3
... Computer 6 ... Electric furnace 5 ... Thickness measuring device S ... Measurement sample

Claims (1)

[Scope of Claims] 1. An ultrasonic probe that is made of an ultrasonic transmitting section and a receiving section, and a buffer section to which the transmitting section and receiving section are attached and that propagates the ultrasonic waves, and that is brought into contact with a measurement sample. , an in-sample propagation time calculation means for calculating the propagation time of the ultrasonic wave within the measurement sample based on the propagation time of the ultrasonic wave between the transmitting section and the receiving section of the ultrasonic probe; and the measurement sample. in-sample propagation velocity calculation means for calculating the propagation velocity of the ultrasonic waves in the measurement sample from the propagation time of the ultrasonic waves in the measurement sample and the thickness of the measurement sample in the ultrasonic propagation direction; A mechanical property measuring device comprising mechanical property calculation means for calculating various mechanical properties such as rigidity of the measurement sample based on a propagation velocity and a density of the measurement sample.