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EXPERIMENTAL INVESTIGATIONS OF 25
ACCELERATIONS AND VIBRATIONS ON VEHICLES AND BOATS

an active windshield. Belgacem et al. [19] focused on the cancellation of road noise, from the
analysis of vibration transmission paths for an automotive suspension to the design of an active
control system using inertial actuators on a suspension to reduce the vibrations transmitted to
the chassis. Matilainen and Tuononen [20] determined the the tyre contact length on dry and wet
roads measuring the accelerations of the inner liner with a three-axial accelerometer. Aranda et
al. [21] improved the design of a multivariable robust controller so that it will be able to reduce
incidences of motion sickness on high speed ferries. Kuznetsov et al. [22] analyzed an improved
suspension system with the incorporated inerter device of the quarter-car model to obtain
optimal design parameters for maximum comfort level for a driver and passengers. Ahn [15]
focused on the discomfort of vertical whole-body shock-type vibration in the frequency range of
0.5 to 16 hz. Kim et al. [14] evaluated driven two passenger cars at several speeds over several
road profiles to evaluate the subjective rating of ride comfort.

The first objective of this study is to measure the hydrodynamic accelerations of Istanbul
AFAD’s inflatable boats. The measurements in seas can lead the future researchers to design
proper hull shapes and seating that can help people from severe impact injuries. The second
objective of this research is to identify the environmental factors affecting individual
susceptibility to motion sickness during the road transport. The measurements can be used to
analyze the quality of roads.

2. Vibration Analyses

For generations, boaters have experienced the danger of slamming at high speeds in rough
conditions. Currently, a number of national and international regulatory and certification
organizations have published specific standards intended to limit impact exposure on boat
passengers and operators. While it is well known in the scientific community that acute injury
in slamming events results from impact, not form vibration, most of these standards are based
on different methods of reducing complex whole-body vibration (WBV) exposure data to
simple single-figure values.

There is no doubt that being exposed to vibration is healthy. Vibration can cause various health
problems including accelerated aging of spinal disks and cartilage. Those problems contribute to
cumulative injuries that can weaken structures and increase the risk of acute injury. However
acute injury is most commonly triggered by impacts.

The most severe injuries caused by slamming in high-speed boats include fractures in vertebrae
and extremities, and ruptures of intervertebral disks including those in the neck. A fast boat in
motion even on a relatively calm sea is bafflingly dynamic, making it difficult to accurately
predict the slamming loads passengers in a particular boat in particular conditions will be
exposed to. It is safe to say that risk of acute injury is proportional to the level of energy
absorbed form a particular slam but accurately predicting the magnitude of any slam is
practically impossible.

2.1 Motion Sickness

By definition motion sickness or kinetosis is a condition in which a disagreement exists between
visually perceived movement and the sensory system’s sense of movement. It may be caused by
different type of motion environments (e.g., cars, boats, planes, funfair rides, etc.). Factors
which are conducting motion sickness sensitivity can be divided into two groups:

Sayı 3, 2015 GiDB|DERGi