Hitachi, Ltd.

Masaharu Sugano

Toshihiko Horiuchi

Takao Konno

Kazuhiro Umekita

Yasuyuki Momoi

Masahiko Inoue

Yuuji Tadano

Makoto Yamakado

Wataru Yamagishi

Yuji Tadano

The testing performs a vibration excitation testing of a part of the structure, performs a numerical calculus of vibration response of the other parts of the structure, and calculates the vibration response of a whole of the structure by combining these two methods. Testing includes calculating a position of a point of exciting force on the basis of vibration exciting, and calculating a reaction force on the basis of a load detected and the position of the point of exciting force. Then, a displacement of a numerical model is computed by using the reaction force calculated and a known external force, and calculating a vibration exciting machine displacement command value on the basis of the displacement. A drive drives the vibration exciting on the basis of an output thereof. Vibration excitation is performed in the translational direction as well as the rotational direction.

Vibration exciting apparatus and vibration testing apparatus for structure using same

Multiple degree of freedom vibration exciting apparatus and system

A simulation apparatus for simulating vehicle movement during actual running has a mock vehicle that is provided with a truck and a vibrator, and a numerical model that is virtually connected to the mock vehicle and stored in a digital computer. Wheels are joined to the bottom portion of the truck, and a driving machine for rotationally driving the wheels is provided under the wheels. The driving machine drives the wheels in such a manner as to simulate a running surface such as a road or rails. The rotation of the wheels causes the truck to generate reaction force. A reaction force measuring device measures this reaction force. Based on a resulting measurement value and the numerical model stored in the digital computer, the digital computer calculates a vehicle movement after a lapse of a preset time. A controller controls the vibrator so as to realize the calculated vehicle movement.

Vehicle testing apparatus and method thereof

A centrifuge model test apparatus is accommodated in a pit, and comprises a vertical rotary shaft, a rotary arm horizontally secured to the rotary shaft, a swing bucket suspended from and supported at a pin on the rotary arm and located near the end thereof so as to be movable in the radial direction of the rotary arm or fixed, and a drive unit for rotating the rotary shaft. As the drive unit is driven and the rotational speed of the rotary shaft increases, the swing bucket is raised together with a sample contained therein due to the centrifugal force with the pin as a center and is placed at a nearly horizontal position when a predetermined rotational speed is reached. A partitioning plate provided under the swing bucket is moved upwards at the time when the swing bucket is raised, and the volume and surface area of the space defined by the partitioning plate and the pit reduce, and the frictional force due to the resistance of the air decreases. This makes it possible to increase the radius of the rotary arm or the load weight on the sample without increasing the driving force. As the rotary arm is made of high damping and easily welded material, vibration caused by resonance can be reduced when the testing apparatus of the centrifuge model is operated with a vibration generating device installed in the testing apparatus.

Centrifuge model test apparatus

Growing community of inventors

Ibaraki-ken, Japan

Masaharu Sugano