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Nowadays modeling with real life objects is too expensive and requires a lot of time. Changing some details of the system to get sought results, especially when we talk about vehicles as mechanical systems, sometimes is nearly impossible in real life cases. The aim of this study was to develop a virtual model that would allow to estimate the dynamics of the vehicle at specific situations and to identify impact of input parameters and environment. The quarter-car and half-car methods are well known particularly when we talk about hand calculations but it consumes too much time and detail level is inadequate so the use of specific software that enables us to simplify calculations is suggested. 3D modeling software provides an opportunity to get proper results and often allows elimination of experiments with material objects giving that the models complies well with real objects behavior. For this reason it is important to create adequate model to get proper results. This paper presents such model where main parameters are mass, damper, rigidity and wheel (as a complex of spring and damper) parameters. These parameters were set when creating a model with Motion add-in in SolidWorks software. Also various types of roads (as an environment) were modeled with different surfaces like road with one pit across, pit for wheels on one side, pits that are placed sequentially on the opposite sides, road bend (adding a path of a model movement) and other. [ABSTRACT FROM AUTHOR]

According to World Health Organization obesity is one of the greatest public health challenges of the 21st century. It has tripled since the 1980s and the numbers of those affected continue to rise at an alarming rate, especially among children. There are number of devices that act as a prevention measure to boost person's motivation for physical activity and its levels. The placement of these devices is not restricted thus the measurement errors that appear because of the body rheology, clothes, etc. cannot be eliminated. The main objective of this work is to introduce a tool that can be applied directly to process measured accelerations so human body surface tissue induced errors can be reduced. Both the modeling and experimental techniques are proposed to identify body tissue rheological properties and prelate them to body mass index. Multi-level computational model composed from measurement device model and human body surface tissue rheological model is developed. Human body surface tissue induced inaccuracies can increase the magnitude of measured accelerations up to 34% when accelerations of the magnitude of up to 27 m/s(2) are measured. Although the timeframe of those disruptions are short - up to 0.2 s - they still result in increased overall measurement error., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Due to their small size, low weight, low cost and low energy consumption, MEMS accelerometers have achieved great commercial success in recent decades. The aim of this research work is to identify a MEMS accelerometer structure for human body dynamics measurements. Photogrammetry was used in order to measure possible maximum accelerations of human body parts and the bandwidth of the digital acceleration signal. As the primary structure the capacitive accelerometer configuration is chosen in such a way that sensing part measures on all three axes as it is 3D accelerometer and sensitivity on each axis is equal. Hill climbing optimization was used to find the structure parameters. Proof-mass displacements were simulated for all the acceleration range that was given by the optimization problem constraints. The final model was constructed in Comsol Multiphysics. Eigenfrequencies were calculated and model's response was found, when vibration stand displacement data was fed into the model as the base excitation law. Model output comparison with experimental data was conducted for all excitation frequencies used during the experiments.