This study examined injuries sustained by a six-year-old child dummy in a numerical dolly rollover crash using a Toyota Yaris 2010. A harmonic dynamic system (HDS) composed of spring, dampers, and masses with a Low Back Booster (LBB) is denominated as HDS-LBB model. The HDS-LBB was designed to allow damping movements along three Cartesian axes (X, Y, Z) to reduce the energy transferred to the child by a motor vehicle accident and avoid a high injury risk. The HDS-LBB incorporates springs into the vertical axis to decrease the vertical movement during the rollover. The numerical analysis was conducted using LS-Dyna® R12.1 version during an interval of 1 s, and the boundary conditions were set by the Federal Motor Vehicle Safety Standard (FMVSS) 213 for child restraint recommendations and the FMVSS 208 for a dolly rollover procedure. Data on head and thorax decelerations, neck flexion-extension, and thoracic deflection were acquired at a rate of 1 ms. The injury values obtained by the HDS-LBB were compared with the injury values by another configuration denominated LBB-ISOFIX to assess the effectiveness of the model proposed. The results show a higher peak injury value in the neck and thorax because of seatbelt displacement across the child’s shoulder. Nevertheless, despite this seatbelt behavior, the injuries sustained remained below the Injury Assessment Reference Values (IARVS).

Side impact crashes are one of the most dangerous impact scenarios that a child can suffer. Studies by the National Highway Traffic Safety Administration (NHTSA) have shown that the head and Thorax regions are affected severely. The objective of this work is to perform a numerical evaluation of the oblique pole-side test considering the FMVSS 214-P standard to estimate the Head, Neck, and Thorax injuries for a six-year-old child positioned in the rear seat without any Child Restraint System, two configurations were performed for the oblique pole-side impact: a nearside and a far-side positioning configuration. A six-year-old Human Body Model (HBM) denominated Scalable PIPER Child Model, and the Ford Explorer 2003 were used to perform the test in the LS DYNA® software to assess the biomechanics involved in the crash scenarios. The approach considered a comparative case study with the baseline of the six-year-old child PIPER model to ensure that the positioning adjustment has not affected the mesh quality and interior components for the PIPER child model. The outcomes obtained in case 1 show that the modified PIPER child model has slight outcomes at the shoulder and pelvis zone due to the differences in the body positioning and not by the mesh or the interior interaction between the components. The outcomes obtained in case 2 reflect that the nearside setup obtained the higher measurements for the child occupant. The A c 3 m s for Head at nearside test to overcome the Side Criteria established by the Assessment Protocol Child Occupant Protection by Euro NCAP, the kinematics behavior demonstrates the importance of researching children in side crashes to enhance child security, especially in the oblique pole side impact.

According to the World Health Organization (WHO), approximately 1.3 billion people experience visual impairments. Daily exposure to various levels of luminous beams directly impacts the front layer of the visible structure, leading to corneal injuries. To comprehensively understand this, we reconstructed a three-dimensional model utilizing the PENTACAM^® system. This enabled us to accurately determine the 50th percentile dimensions of the fibrous layer of the eyeball. Using the Ogden mathematical model, we developed a 3D cornea model, treating it as a soft tissue with predictable behavior, considering mechanical properties such as viscoelasticity, anisotropy, and nonlinearity. Employing the Finite Element Method (FEM), we analyzed five distinct test scenarios to explore the structural response of the cornea. Luminous beam properties were instrumental in establishing varying mechanical loads, leading to structural deformations on the corneal surface. Our findings reveal that when a smartphone’s screen emits light at a frequency of 651.72 THz from 200 mm, displacements in the corneal layer can reach up to 9.07 µm. The total load, computed by the number of photons, amounts to 7172.637 Pa.

Some common conductive polymers are polyfuran, polyacetylene, polythiophene, and poly-pyrrole. Since their discovery, many researchers have been exploring and evaluating their conductive and electronic properties. Various applications have been developed for conductive materials. Their biocompatibility offers a new alternative for studying and solving complex problems, such as cellular activity, or, more recently, for use as neural implants and as an alternative to spinal cord regenerative tissue. This is particularly true for the use of poly pyrrole. The main obstacle lies in estimating some of the mechanical properties, such as Young’s or shear modulus values for poly pyrrole, since these vary depending on the type of synthesis used. This article outlines a composite methodology for characterizing the elastic modulus according to ASTM D882 and the shear modulus according to E143 standards. It is specifically designed and applied for 3D composite samples involving PLA and PPy, where the PPy was processed by plasma oxidation. As a result, an increase of 360.11 MPa in the modulus of elasticity is observed on samples coated with poly pyrrole. The results are evaluated through a numerical test using COMSOL Multiphysics software 6.2 version, finding a similar behavior in the elastic zone, as indicated by the stress–strain diagram. The statistical analysis yields consistent data for tensile and shear results, with low to moderate variability.

This research examines a 2D Harmonic Dynamic System (HDS) proposed to reduce the kinetic energy transferred to the child body in a motor vehicle crash with the purpose of its subsequent implementation for use in children with bone-degenerative diseases such as Osteogenesis Imperfecta (OI). The 3D model from the HDS was modified into a simplified 2D model that considers the components present in the XY plane such as rails, springs and shock absorbers that damping excessive movements along the X axis. The 2D multibody numerical analysis was conducted using WorkingModel® during an interval of 140 ms, the boundary conditions were in accordance with the United Nations Economic Commision for Europe UN Regulation No. 129 for a CRS frontal test evaluation (CRS). The kinetic behavior observed shows a great correlation between the 2D multibody test and the test evaluation from the literature. Although the results were satisfactory for the 2D case proposed, the multibody analysis needs to be revised in a 3D multibody test considering a more detailed CRS and HDS as well as components such seatbelt.