INTRODUCTION - Injury Biomechanics and Control: Optimal Protection from Impact - page 13

using a version of the multibody dynamic simulator, the Articulated Total
Body (ATB) program, which has been validated extensively by crash sled
tests. The model was used to predict the responses of wheelchair - occupant
systems in various crash environments. To evaluate the crashworthiness of
different wheelchair tiedowns, the sensitivity of the dynamic responses to
several design parameters, such as tiedown stiffness, wheel stiffness, and
tiedown positions, was studied and optimal values of these parameters were
obtained. In addition, the model was used to study the sensitivity of crash
sled test results to impact pulses confined to a prescribed “corridor” in an
effort to develop a sled test standard. It was found that a corridor defined
by the International Organization for Standardization (ISO) allowed large
variations in the responses and should be tightened.
To improve the protection of a wheelchair-seated person traveling in a
vehicle from injuries in a crash, Balandin et al. (2008) proposed to attach
the wheelchair to a movable platform separated from the vehicle body by
means of a shock isolator. The control of the platform should be designed
to reduce the occupant's injury risk compared to attaching the wheelchair
directly to the vehicle. The isolator design was based on the minimization
of the force transmitted to the wheelchair occupant, provided that the space
allowed for the platform to move relative to the vehicle was constrained.
The possibility of pre-acting control when the isolator is engaged for a time
prior to the crash was discussed. A multibody model of the platform-based
occupied wheelchair was utilized for full-scale simulation of the response of
the system to a crash pulse. The simulation showed a noticeable reduction
in the injury risk due to the platform and an even greater reduction of injury
with pre-acting control.

1.2.8 Reviews

The first review related to the development of the theory of optimum shock
and vibration isolation was compiled by Balandin, Bolotnik, and Pilkey
(1998) and covers the period from the beginning of active studies on that
subject matter in the late 1950s to 1997. It contains a concise outline of the
basic concepts and an annotated bibliography of relevant publications.
Later, these authors published a more detailed review (Balandin, Bolot-
nik, and Pilkey, 2000) that characterized the historical perspectives and
state of the art of the theory of optimal shock isolation. Mathematical state-
ments of basic problems were given and solutions of these problems for
single-degree-of-freedom models were presented. Separate sections were
devoted to the limiting performance analysis and the parametric optimiza-
tion of shock isolation systems. Some topical issues, essential for the further