Multibody Dynamics Approaches for Biomechanical Modeling in Human Impact Applications

Abstract

Abstract.The construction of multibody biomechanical models for impact is discussed here with the emphasis on the formulation aspects. First the relations between the human or the dummy anthropometric data and the rigid bodies in the model are presented. The motion restrictions between the different anatomical segments of model can be defined as kinematic joints, suitable to represent mechanical joints of dummies or a simplified kinematics of human joints, or as contact/sliding pairs, which are used to describe realistic human like anatomical joints. Another particular aspect of biomechanical models is the representation of the range of motion of the anatomical joints. This is achieved either by setting proper contact pairs between the adjacent anatomical segments or by setting resisting muscle forces or resisting moments that develop when the relative orientation between the segments reach critical values. Another fundamental aspect of the models is the ability to represent the contact geometries and the contact forces with realism. In fact, the outcome of all injury indexes predictions is strongly dependent on the quality of the representation of the contact. Contact models suitable to be used in biomechanical models, to represent the contact between anatomical segments of the biomechanical model or between these and external objects, are presented and discussed emphasizing the requirements to develop more advanced biomechanical models. The current biomechanical models either do not include muscle actions or, at the most, include a reflexive muscle contraction. It is suggested here that for the case of standing passengers it is important to include in the biomechanical models muscle models that allow for the representation of the muscle voluntary contractions and joint stiffening. It is also suggested that the evaluation of the models leading to the identification of such actions can be done by using techniques similar to those used in the evaluation of muscle force sharing in different human motions.

Multi-body dynamics in vehicle engineering

“…Representative literature for multi-body vehicle dynamics, including biomechanical issues are reported. [95][96][97][98][99][100][101][102][103][104][105][106] Infinitesimal elasto-multi-body dynamics of powertrain systems With improved methods of solution, including integration algorithms for stiff systems (widely split eigenvalue systems or broadband frequency response systems), 14,24,[107][108][109][110] multibody analysis found its way into the multi-scale domain with integrated simultaneous dynamics across the physics of scale. In this domain, the flexibility of components should be taken into account.…”

“…Representative literature for multi-body vehicle dynamics, including biomechanical issues are reported. 95–106…”

State Estimator Design for Real-time Controlled Restraint Systems

“…The family of dummies modeled in the Madymo [7], has proven to be versatile and accurate for different types of crashes and dummies [22]. Besides, the available coupling between Madymo and MAT-LAB/Simulink is of great advantage here.…”

“…However, a state transformation is undesirable, since the nonlinear output equation in (2) can then not be used to predict the output z. For this reason, the observer is designed with the unbalanced system G 22 .…”

Multibody modelling of the foot for the biomechanical analysis of the ankle joint during running: A narrative review

“…21,23,24 In inverse dynamics, internal forces are estimated for an observed fully described movement and measured external forces, whereas in forward dynamics, the kinematics of the biomechanical system is estimated by applying a set of known forces. 25 These estimations can potentially suffer from inherent errors that may result from the movement of markers relative to the underlying bones, incorrect modelling assumptions of the dynamic response of the biomaterials that lead to inconsistent kinematics and force estimations, 26 inadequate evaluation of muscle actions, or the use of algorithms in inverse and forward dynamics which can introduce numerical errors. 27 The main goal of this work is to provide a general overview of generic foot multibody models and their application to the analysis of ankle biomechanics during running.…”