Premium
Investigation of gas‐assisted injection molding. Part III: Effect of gas channel design on part bending strength
Author(s) -
Chen ShiaChung,
Hu ShengYan,
Huang JengSheng,
Chien Rean Der
Publication year - 1998
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.10276
Subject(s) - moment of inertia , materials science , bending , beam (structure) , finite element method , molding (decorative) , structural engineering , bending stiffness , bending moment , stiffness , channel (broadcasting) , pure bending , cross section (physics) , moment (physics) , inertia , mechanical engineering , composite material , mechanics , engineering , physics , electrical engineering , classical mechanics , quantum mechanics
Numerical simulation and experimental measurements were carried out to investigate the effect of gas channel design on the bending performance of gas‐assisted injection molded parts. Plate parts designed with various channel geometries were gas‐assisted injection molded. Part flexible strength were measured via bending tests. It was found that part stiffness basically increases linearly with the inertia moment of the plate. The gas channel introduces an additional moment of inertia, the amount of which is determined by the shape and the dimension of the channel section as well as the hollowed core geometry. An analysis algorithm based on DKT/VRT elements superimposed with beam elements representing gas channels of various section geometries was developed to evaluate part bending behavior. An equivalent diameter was assigned to the beam element so that both the original gas channel and the circular beam have the same moment of inertia. The analyzed results from this model of 2 1/2‐D characteristics were also verified with both 3‐D and 2 1/2‐D analyses using ANSYS. The present simulations show reasonable accuracy as compared with experimental measurements and predictions from ANSYS. This investigation also indicates that it may be feasible to use the same CAE finite element model implemented for process simulation of gas‐assisted injection when performing part structural analysis as well as warpage calculation, resulting in great computational efficiency for industrial application.