Rotating Bending Fatigue Testing Machine@[Japan]
YAMAMOTO METAL TECHNOS CO., LTD.
Japanese
Top Company Info News Products Site Map contact
TOP
GIGA QUAD Line up
YRB200
YRB300L
Corrosion environmental testing unit YRB200-010
High temperature environmental testing unit(Halogen Lamp)
2-step variable loading unit
Q&A
Libcy
Technical information



papers
Products

Dual-spindle rotating bending fatigue testing machine


GIGA QUAD
Q&A
GIGA QUAD Q&A
Contact

What is the superiority of the rotating bending machine comparing with the ultrasonic machine?


These 3points are fundamental advantages of the rotating bending machine.
1.Heat generation of the specimen takes place in the case of ultrasonic tests.
2.When we use the ultrasonic fatigue instrument, the shape of a specimen is restricted depending on the resonance conditions. But, we can perform fatigue tests for various shapes of specimens, if we use the rotating bending fatigue testing machine here explained.
3.S-N characteristics depend on the loading frequency.
This fact is repeatedly confirmed by many researchers all over the world.
Thus, it is very difficult to obtain the real S-N property at usual frequency(50Hz/60Hz) by using the ultrasonic fatigue testing machine.



What is the difference between both-handed type and one-handed type?


When both-handed type is used, the loading type becomes guniform bendingh, while when one-handed type is used, the loading type is cantilever bending.
In the case of cantilever bending, the bending stress increases depending on distance from the loading point.
So hourglass type of specimens is accepted to keep the fracture at the critical portion.
Based on such a situation, the effective volume of the specimen in the cantilever bending is a little smaller than that in the uniform bending.
Thus, fatigue strength in the cantilever bending would be a little higher than that in the uniform bending.
But, the difference is usually very small within a few percents.
That is the reason why many users have already used one-handed type.


We have already performed fatigue test by axial loading. But furthermore, do we have to performed fatigue test by rotating bending.


The loading types between axial loading and rotating bending are different.
In the case of axial loading is uniform on the critical section.
While in the case of rotating bending is graduated, that is ,the loading on the surface is maximum, but the loading of the center is zero.
Therefore, especially effect of surface treatment on the fatigue strength makes quite different between them.
Thus, both types of fatigue tests are important to make sure the fatigue property.
This is our fundamental standpoint to develop the rotating bending testing machine.


What is most difficult subject in the development of GIGA QUAD?


The most difficult subject was the development of high performance spindle having a small eccentricity.
If the eccentricity becomes large, problems of vibration and noise take place in the fatigue tests, and some extent of error is included in the applied stress.
Actually, the reason why we can keep such a small eccentricity is to use a collet chuck and a collet nut.
But there is another main reason. That is the precision of shape and dimensions of the spindle and every component around the spindle.
How can we produce those precise parts?
And how can we assemble these parts??
This is the most important and difficult subject to develop the high performance machine.


TECHNICAL INFORMATION
>> PageTop



YAMAMOTO METAL TECHNOS CO., LTD.
Rotating Bending Fatigue Testing Machine@[Japan]

4-7, Setoguchi 2-chome, Hirano-ku, 547-0034 Osaka Japan
TEL: 81-6-6704-1800@E-mail: info@yama-kin.co.jp


Top | Company Info | News | Products | Site Map | Contact