2024 年 90 巻 936 号 p. 24-00039
This paper deals with the reproducibility of the running safety limit diagram of multi-connected vehicle using the reduced-order-model. The vehicle model consists of 10 cars and has 210 degrees of freedom. It needs much time to simulate the car’s behavior and make the running safety limit diagram by numerical calculation because the model has enormous degrees of freedom, so we consider about model reduction to decrease the calculation time. So far, when the types of car’s characteristics or input waves have been changed, we reconstructed reduced-order-model for each case, so it is difficult to make the running safety limit diagram which needs various types of input waves (many cases of frequency or acceleration amplitude) when using the reduced-order-model. Therefore, in this study, we use an index called as ‘multiplicity’ of mode for all of 210 modes, and make ‘common’ reduced-order-model by using modes whose multiplicities are high. As a result, if the common model included 20 – 60 modes, the model could reproduce the running safety limit diagram of original model, and the calculation cost decreased by 75 % when 20 – 50 modes, and by 35 % when 60 modes. Considering both accuracy and calculation cost, 50 modes was better to make the diagram. Moreover, the reduced-order-model which included 50 modes was also applicable to the running safety limit diagram using real seismic waves.
