This paper presents the results of the fundamental researches on a newly devised “Dynamic Load Testing Machine for Architectural Materials applying Automatic Control Techniques”.
Recently high-storied buildings began to draw increasing attentions in this country where earthquakes occur frequently. During an earthquake the architectural materials such as beams of the high-storied buildings are deformed dynamically corresponding to the earthquake's wave form.
Needless to say, a reasonable design of high-storied building should be based on a secured knowledge concerning the dynamics of the beam in the structure.
To the authors' knowledge, it is only possible to perform static or repeated load tests of the beam and almost impossible to perform a dynamic test by the conventional material testing machine.
The first aim of the newly devised load testing machine is to dynamically deform a test beam in a prescribed wave from of oscillation. The wave form can be arbitrarily prescribed except that the frequency of its highest harmonic cannot dexceed 10 c. p. s.. This frequency limit is set by experience taking into account the wave forms of earthquakes so far recorded. The second aim is to make the static and dynamic characteristics of the testing machine independent of the characteristics of a test beam attached to the testing machine.
This new load testing machine is a kind of electro hydraulic servosystem based on some original ideas.
The hydraulic servomotor which gives deformation to the beam and is a main power element of the load testing machine has a spring type load resulting from the beam deformation. The dynamic characteristics of the spring loaded servomotor is analyzed, for they have not been reported in the published papers.
As the results of the above analysis, it becomes clear that the second aim is attained by an appropriate choice of the ram area of the servomotor.
It is shown also that a simple electronic compensator is additionally needed to attain the first aim.
The experimental frequency responses of the load testing machine with an electronic compensator and a properly designed servomotor show satisfactory results.

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