Process variable

About: Process variable is a research topic. Over the lifetime, 3983 publications have been published within this topic receiving 43130 citations. The topic is also known as: process parameter.

Accommodation of Springback Error in Channel Forming Using Active Binder Force Control: Numerical Simulations and Experiments

Abstract: Springback in a forming process is due to the elastic deformation of the part during unloading This manufacturing defect can be accounted for through proper tooling design or through proper design and control of the magnitude and history of restraining force Using finite element analyses of the process : (1) the effects of restraining force on the springback phenomena when stamping channels from aluminum sheet are investigated ; (2) a strategy to control the binder force during the forming operation in order to reduce springback and simultaneously avoid tearing failure is described ; and (3) a binder force control strategy which provides robustness in the presence of process parameter uncertainty is implemented The process history and controller designed using finite element analyses is then experimentally verified : excellent agreement between simulation and experiments is obtained A binder force history, which leads to a significant reduction in the amount of springback incurred by the formed part without reaching critical stretching conditions, was proposed Although an optimal forming history was found, in order to ensure that part shape error remained minimized even in the event of variations in processing parameters such as friction, a closed-loop control algorithm was developed whereby the binder force is altered during the process in order to provide a robust, repeatable stretching history Experiments were performed using a double-action servo-controlled process and were found to produce the desired results demonstrating both the accuracy of the numerical simulation and the success of the proposed active-binder force control method to obtain net shape

Characterization of process–deformation/damage property relationship of fused deposition modeling (FDM) 3D-printed specimens

Abstract: In this paper, we investigated the process variable effects on the damage and deformational behavior of fused deposition modeling (FDM) three-dimensional (3D)-printed specimens by performing tensile tests and inverse identification analyses. A characterization of the effects of different parametric variations of 3D-printed specimens on fracture properties are a matter of considerable significance that are often overlooked. By combining the infill density and the layer thickness options that are available in the 3D printer machine, six groups with different structural configurations can be obtained. The data and images obtained from experiments are employed to investigate the failure mechanism of 3D-printed specimens and demonstrate the relationship that exists between structural variations and fracture mechanical properties. On the basis of experimental results, a Gurson-type porous plasticity model was used within a 3D continuum finite element model to characterize the process–damage parameter relationship through an inverse identification process.

Process Parameter Optimization of Extrusion-Based 3D Metal Printing Utilizing PW-LDPE-SA Binder System.

Abstract: Recently, with a broadening range of available materials and alteration of feeding processes, several extrusion-based 3D printing processes for metal materials have been developed. An emerging process is applicable for the fabrication of metal parts into electronics and composites. In this paper, some critical parameters of extrusion-based 3D printing processes were optimized by a series of experiments with a melting extrusion printer. The raw materials were copper powder and a thermoplastic organic binder system and the system included paraffin wax, low density polyethylene, and stearic acid (PW-LDPE-SA). The homogeneity and rheological behaviour of the raw materials, the strength of the green samples, and the hardness of the sintered samples were investigated. Moreover, the printing and sintering parameters were optimized with an orthogonal design method. The influence factors in regard to the ultimate tensile strength of the green samples can be described as follows: infill degree > raster angle > layer thickness. As for the sintering process, the major factor on hardness is sintering temperature, followed by holding time and heating rate. The highest hardness of the sintered samples was very close to the average hardness of commercially pure copper material. Generally, the extrusion-based printing process for producing metal materials is a promising strategy because it has some advantages over traditional approaches for cost, efficiency, and simplicity.