Circular Path and Linear Momentum Method for Seismic Response Analysis of Vehicles

Rishi Ram Parajuli,Junji Kiyono

doi:10.3389/fbuil.2016.00016

Abstract

We propose a circular path and linear momentum method for the seismic response analysis of vehicles. This method considers the momentum induced by earthquake excitation and applies the concept of centripetal force acting laterally on the vehicle in addition to longitudinal forces. This method is valid for vehicles at rest as well as those moving at a range of speeds. The vertical responses are calculated using a quarter vehicle model. We also calculate the translational motion of the vehicle using a model with six degrees of freedom. Three vehicle types (car, bus, and truck) were used in the analysis. We compared the result with analysis of the response of a shaking vehicle from video footage recorded during the Gorkha earthquake. We used the input ground motion from 10 large earthquakes of moment magnitudes 6.7 to 9.0. All three components of the ground motion were used in the analysis. Vehicles at rest and moving at various speeds were analysed. The lateral and longitudinal responses of the vehicles were calculated for different vehicle speeds ranging from 0 to 30.0 m/s, PGA excitations and orientations of the vehicle.

Highlights

Driving a vehicle during a strong earthquake can lead to a serious accident if the driver loses control, which can happen even in a moderate-level earthquake when the driver does not feel the ground motion
Drivers’ responses and the characteristics of ground motions during the 1983 M7.7 Nihon-kai-chubu earthquake in Akita Prefecture and the 1987 M6.7 Chiba-ken-oki earthquake in Chiba Prefecture, which both resulted in Japan Meteorological Agency (JMA) seismic intensities of V (JMA, 1996), were surveyed using a questionnaire (Kawashima et al, 1989)
circular path and linear momentum” (CPLM) Method on Seismic Response of Vehicle where m is the mass of the vehicle, K∅ is the rolling stiffness, K is the stiffness of the tire, ∅ is the rolling angle, θp is the pitching angle, h is the height of the center of gravity (CG) of the vehicle mass, and u and v are the longitudinal and lateral velocities of the vehicle, respectively

Summary

Introduction

Driving a vehicle during a strong earthquake can lead to a serious accident if the driver loses control, which can happen even in a moderate-level earthquake when the driver does not feel the ground motion. Earthquake damage to roads and infrastructure can be reduced by strengthening structures and increasing their earthquake resilience, lowering the risk of a vehicle driver losing control during a strong earthquake is more complex, involving mechanical, physical, and psychological factors. This risk depends on the individual’s driving skills, physical and psychological abilities, and on the mechanical properties of the vehicle. Most of the drivers stopped their vehicles (65 and 43.3% in the 1983 and 1987 events, CPLM Method on Seismic Response of Vehicle respectively) because they felt they were in danger. For JMA intensities larger than 4.5, 20% of the drivers stopped on the shoulders of the roads

Methods

Results

Conclusion