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Shape Terra: 열지속특성을 응용한 CAD 피쳐 인식 도구
Ramy Harik,백승엽(Seung-Yeob Baek),Barend-Jan Van Bruchem,Michel Van Tooren (사)한국CDE학회 2015 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2015 No.동계
In many CAD/CAM/CAPP applications, recognizing geometric features is of ubiquitous need. Recognizing and analyzing geometric features in a mechanical part will augment manufacturing knowledge within the product development process. Although feature recognition is progressing steadily in many computer graphics applications, it is still an undiscovered area in mechanical design; we are still lacking a feasible solution for feature recognition that can be applied specifically to the CAD parts. In this paper, we will present Shape Terra; our recent advance in CAD feature recognition technology. Shape Terra identifies the typical mechanical features from a given CAD part by utilizing the findings of traditional heat transfer theory, which says that salient features tend to retain the heat more whereas flat surfaces tend to lose it faster. Furthermore, each feature is analyzed and assigned with its meaning, such as design parameters, manufacturability, and so on. Various CAD/CAM/CAPP applications will profit from such information.
Free vibration analysis of stiffened laminated plates using layered finite element method
Guo, Meiwen,Harik, Issam E.,Ren, Wei-Xin Techno-Press 2002 Structural Engineering and Mechanics, An Int'l Jou Vol.14 No.3
The free vibration analysis of stiffened laminated composite plates has been performed using the layered (zigzag) finite element method based on the first order shear deformation theory. The layers of the laminated plate is modeled using nine-node isoparametric degenerated flat shell element. The stiffeners are modeled as three-node isoparametric beam elements based on Timoshenko beam theory. Bilinear in-plane displacement constraints are used to maintain the inter-layer continuity. A special lumping technique is used in deriving the lumped mass matrices. The natural frequencies are extracted using the subspace iteration method. Numerical results are presented for unstiffened laminated plates, stiffened isotropic plates, stiffened symmetric angle-ply laminates, stiffened skew-symmetric angle-ply laminates and stiffened skew-symmetric cross-ply laminates. The effects of fiber orientations (ply angles), number of layers, stiffener depths and degrees of orthotropy are examined.
Concentrically Loaded Circular RC Columns Partially Confined with FRP
Sahar Y. Ghanem,Issam E. Harik 한국콘크리트학회 2018 International Journal of Concrete Structures and M Vol.12 No.5
Wrapping reinforced concrete (RC) columns with fiber reinforced polymer (FRP) composites is effective in increasing their capacity. The current state of the art concentrates primarily on fully wrapped columns and few studies dealt with partially wrapped ones. The objective herein is to evaluate the effectiveness of partial wraps (or strips) and to develop a confined concrete compressive stress.strain (fc - εc) model that accounts for partial wrapping. Three-dimensional finite element (FE) models are generated to evaluate the influence of different parameters on the behavior of concentrically loaded RC circular columns that are partially and fully wrapped with FRP. The results indicated an increase in ductility as the number of FRP strips is increased, and revealed that longitudinal steel had little influence on the confined fc . εc relationship. The proposed fc . εc model, derived from the parametric study, accounts for the effect of partial and full confinement, the unconfined concrete strength f ′c , and yielding of transverse steel. Comparison of the results generated using the proposed model with FE and experimental results are in good agreement.