| 摘要 |
PURPOSE:To easily excite a cable by a normal mode and to perfrom a high- precise measurement of a natural frequency, by a method wherein an exciting frequency and an exciting force are caused to change continuously, and a cushioning spring is located between a connection cable and a slide metal. CONSTITUTION:A variable speed motor 6 is secured to a base bed 6 to turn a fly wheel consisting of a crank metal 7. A crank pin 8 is situated so that an eccentric distance from the crank metal 7 can be adjusted, and is moved by a crank pin moving device 10. With the crank metal 7 turned, a slide metal 16 is guided by a guide member 18 attached to the base bed 5, and reciprocates in a direction of radius. A displacement gauge 19 outputs the reciprocating displacement distance of the slide metal, and a pulse meter 20 outputs the number of revoutions or the number of exciting frequencies of the motor 6. A connection wires 25, stretched between the other end of the slide metal 16 and a cable 3 to be excited, is provided with a cushioning spring 26 in the middle of the wire, and the wire 25 is connected to the cable 3 through a sleeve 27 for connecting the wire. |
