Technikatörténeti szemle 11. (1979)

TANULMÁNYOK - Petik Ferenc: The development of material testing machines

Development in our century

It the first half of the 20th century only a few essential changes were made on this build-up which can be almost considered as standardized. In Fig. 16 a machine built in Hungary can be seen. In the field of mechanical testing machines a few basic designs are current.

In the last decade the testing of complete .structural assemblies became a necessity in materials testing. Thus strength testers of build-up .system, without a common machine frame were developed, the elements of which can be mounted as required on the structure to be tested.

Material testing specialists were increasingly demanding intertialess dynamometer systems. Pendulum systems, namely, can follow strains in the specimen only with a time delay, in some cases the system starts oscillating. This fact is especially inadvantageous at plotting the yield section of the stress-strain diagram. Efforts were made to realize inertialess load meaisu- rement by employing again steel springs [14] (coil spring at Amsler’s, torsion rod by WPM), the reliable solution, however, was brought only by electronic load measurement [19, 20]. Universal strength testers with electronic dynamometer, variable drive, and with various program control devices (Fig. 17) represent the result of a long sequential evolution. We know, however, that development will continue in the future as well.

17. Universal electronic, testing machine (Zwick & Co)

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