The purpose of this study is to determine limit loads for pipe elbows subjected to in-plane bending moments that tend to close the elbow (i.e., decrease its radius of curvature), and the influence of internal pressure on the value of the limit load. Load-deflection curves were obtained, and from these curves plastic collapse or instability loads at various values of internal pressure were determined. This was done for different pipe bend factors (h = Rt/r2) using the nonlinear finite element analysis code (ABAQUS) with its special elbow element. The limit load was found to increase and then decrease with increasing pressure for all the elbow geometries studied.
The purpose of this study is to determine limit loads for pipe elbows subjected to inplane bending moments that tend to open the elbow (i.e., increase its radius of curvature), and the influence of internal pressure on the value of the limit load. Load-deflection curves were obtained, and from these curves plastic collapse and instability loads at various values of internal pressure were determined. This was done for different pipe bend factors (h = Rt/r2) using the nonlinear finite element analysis code (ABAQUS) with its special elbow element. A set of limit curves was generated from the results. These curves show the variation of collapse and instability loads with internal pressure for different elbows. Collapse loads were found to increase and then decrease with increasing pressure for all the elbow geometries studied. Instability loads were difficult to reach because of the large stiffening effect of the elbow cross-sectional deformation, and they were generally found to decrease with increasing pressure.
The purpose of this study is to investigate the effect of pressure on the strain and stress analysis of pipe elbows subjected to in-plane bending moments. A finite element model for the bend was constructed and loaded with a pressure of 1200 psi and end moments taking geometric and material nonlinearities into account using (ABAQUS) nonlinear finite element code. The pressure changes the effective stress distribution and location of the initial yielding from the inside surface of the elbow crown to the outside surface for the closing moment case and increases the moment of yielding. For the opening moment case, yielding starts at the inside surface of the elbow crown with and without pressure. The pressure changes the location of the maximum axial strain at instability for the closing and opening cases, and it also changes the ovality of the cross section in both cases.
A new design of friction sensor, intended for use in industrial process applications, such as metal forming, has been developed. The sensor consists of a diaphragm whose outer surface is flush with the surface of the tool and whose inner surface is instrumented with strain gauges. Relative to previous sensor designs, this sensor offers reduced disturbance of the frictional interaction between the tool and the workpiece. A proof-of-concept prototype has been constructed and tested in a laboratory test apparatus. The results of testing validate the anticipated performance, based on finite element modeling. The sensor is able to measure both shear and normal forces and, of greater significance, is able to simultaneously differentiate between the two types of loading.
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.