The objective of this study was to investigate the effects of various occlusal loads on the stress distribution of the buccal cervical region of a normal maxillary second premolar, using a three dimensional finite element analysis (3D FEA).After 3D FE modeling of maxillary second premolar, a static load of 500N of three load cases was applied. Stress analysis was performed using ANSYS (Swanson Analysis Systems, Inc., Houston, USA). The maximum principal stresses and minimum principal stresses were sampled at thirteen nodal points in the buccal cervical enamel for each four horizontal planes, 1.0 ㎜ above CEJ, 0.5 ㎜ above CEJ, CEJ, 0.5 ㎜ under CEJ.The results were as follows 1. The peak stress was seen at the cervical enamel surface of the mesiobuccal line angle area, asymmetrically. 2. The values of compressive stresses were within the range of the failure stress of enamel. But the values of tensile stresses exceeded the range of the failure stress of enamel. 3. The tensile stresses from the perpendicular load at the buccal incline of palatal cusp may be shown to be the primary etiological factors of the NCCLs. [J Kor Acad Cons Dent 31(6):427-436, 2006]
Corrosion is a factor that decreases the ultimate strength of a structure, which can lead to structural failure in an aged structure. This study proposes a reliable method to predict the ultimate strength reduction caused by pitting corrosion of a structure at various ages. Hence, the objectives of this study are as follows: (1) finding relationship between the ultimate strength reduction and pit depth and (2) finding relationship between the ultimate strength reduction and the age of structure. The presented method has six steps and was assessed by applying it to the simplified example of a thin-plate panel structure. The ultimate strengths of the panel with different pit depths were calculated using finite element analysis. The effects of material and geometric nonlinearities as well as the initial imperfections and buckling were also considered. A linear regression model, representing the relationship between the ultimate strength reduction and pit depth, was then developed. Furthermore, using the experimental data, the weighted mean value of ultimate strength reduction was acquired for different age groups of the panel. The introduced stepwise approach contemplates the nonlinearity of pitting corrosion with time by considering the experimental data. As corroborated by the successful application of the presented methodology, this method is more accurate, compared to the accepted practices available in the literature.
Abstract. Accurate tire slip estimation might be regarded as a small portion of the vehicle safety but is important criterion. Furthermore, as an autonomous vehicle system gets sophisticated, this type of technique will be more necessary. In this paper performance analysis for slip estimation in various situations is presented with several commonly known filter-extended Kalman filter (EKF) and unscented Kalman filter (UKF). Tire slip behaves differently depending on the surface type, the motion of the robot, and other environmental factors. Therefore, different kinds of situations and conditions are considered to estimate more accurate tire slip. Also as far as the tire slip is not based on actual data, it will be assumed to imitate the real tire slip behavior based on other study data. Finally, the performances of two filtering algorithms are compared to find more adequate algorithm with respect to the given condition for the future experimental results.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.