Verification measuring and evaluation method for seismic response of diesel engine by shaking-table excitation.

As far as internal combustion reciprocating engines such as diesel engines are concerned, it is difficult to evaluate the seismic response because the axial vibration in the shafting system originates from torsional vibration, harmonic radial components of the gas and mass force, and seismic force. This paper presents a study on the response of a diesel engine used in an emergency power supply system during strong earthquakes. We conducted experiments to study the characteristics of nonlinear vibration using a shaking-table and calculated the axial behavior of the crankshaft on the oil film in the case of a shut-down and of a running engine. As a result, a good agreement was obtained between the calculated results and experiment ones. The proposed method of separating the response of seismic force from the other forces using coherency function was demonstrated to be effective.