DSpace Collection:http://hdl.handle.net/10722/444512024-03-28T12:25:58Z2024-03-28T12:25:58ZDevelopment of a pilot manufacturing cyberinfrastructure with an information rich mechanical cad 3D model repositoryBharadwaj, AkshayXu, YangAngrish, AtinChen, YongStarly, Binilhttp://hdl.handle.net/10722/3415212024-03-13T08:43:28Z2019-01-01T00:00:00ZTitle: Development of a pilot manufacturing cyberinfrastructure with an information rich mechanical cad 3D model repository
Authors: Bharadwaj, Akshay; Xu, Yang; Angrish, Atin; Chen, Yong; Starly, Binil
Abstract: Data driven advanced manufacturing research is dependenton access to large datasets made available from across theproduct lifecycle-from the concept design phase all the waydown to end use and disposal. Despite such data being generatedat a rapid pace, most product design data is archived ininaccessible silos. This is particularly acute in academic researchlaboratories and with data generated during product design andmanufacturing courses. This project seeks to create aninfrastructure that allow users (academia and the general public)to easily upload project data and related meta-data. Currentmanufacturing research must shift from siloed repositories ofproduct manufacturing data to a federated, decentralized, openand inter-operable approach. In this regard, we build 'FabWave'a cyber-infrastructure tool designed to capture manufacturingdata. In its first pilot implementation, we focused our attentionto gathering information rich 3D Mechanical CAD data andrelated meta-data associated with them, with the intent to makeit easier for users to upload and access product design data. Wedescribe workflows that we have initially tested out within thetwo academic universities and under two different coursestructures. We have also developed automated workflows togather license appropriate CAD assemblies from commercialrepositories. Our intent is to create the only known largestavailable CAD model set within academia for enabling researchin data-driven computational research in digital design,fabrication and quality control.2019-01-01T00:00:00ZDirect droplet writing - A novel droplet-punching capillary-splitting 3D printing method for highly viscous materialsXu, YangQi, FangjieGao, XiangyunShan, YujieZhou, YunChen, Yonghttp://hdl.handle.net/10722/3415062024-03-13T08:43:20Z2021-01-01T00:00:00ZTitle: Direct droplet writing - A novel droplet-punching capillary-splitting 3D printing method for highly viscous materials
Authors: Xu, Yang; Qi, Fangjie; Gao, Xiangyun; Shan, Yujie; Zhou, Yun; Chen, Yong
Abstract: The drop-on-demand (DOD) based three-dimensional (3D) printing methods can fabricate an object with a high level of accuracy and shape complexity using multiple materials. However, a key limitation of the DOD approaches such as ink jetting is only the inks with low viscosity can be used. Such low-viscosity restriction severely limits the material options for the DOD-based 3D printing methods. To address the viscosity issue, we have developed a novel drop-on-demand 3D printing method called direct droplet writing (DDW) for highly viscous material. One main idea of the DDW process is to use direct droplet-punching to enable the printing of materials that may have a viscosity over 190,000 mPa·s; and another main idea of the DDW process is to use capillary-splitting to avoid common issues of various ink-jetting approaches, including splashing, droplet deflection, and satellite droplets. The DDW process can reliably fabricate 3D structures using a wide range of materials that are challenging for the jetting-based and extrusion-based methods. Analytical models to characterize the DDW process are presented. A set of test cases have been conducted using the in-house developed prototype system to characterize the relationship between droplet size and process parameters such as droplet punching speed and dispensing gap. Various materials, including high-loading photocurable tricalcium phosphate (TCP) ink and polyurethane (PU) leather ink, were successfully used in the DDW process. In addition to a much broader range of 3D printable materials, the DDW process is robust, without ink clogging or leaking, and can achieve consistent printing results using digitally controlled droplets.2021-01-01T00:00:00ZA vibration-assisted separation method for constrained-surface-based stereolithographyXu, YangZhu, YizhenSun, YifengJin, JieChen, Yonghttp://hdl.handle.net/10722/3412992024-03-13T08:41:44Z2020-01-01T00:00:00ZTitle: A vibration-assisted separation method for constrained-surface-based stereolithography
Authors: Xu, Yang; Zhu, Yizhen; Sun, Yifeng; Jin, Jie; Chen, Yong
Abstract: For the bottom-up based stereolithography (SL) process, a separation process is required to detach the newly cured layer from the constrained surface in order to accomplish the fabrication of the current layer. Excessive separation force will cause damage to the built layers and the constrained surface. Different surface coatings, platform motions including tilting and sliding, and the utilization of oxygen-permeable films have been proposed to address the separation-related problems. Among these approaches, there is a limited study on the vibration-assisted (VA) separation method to reduce the separation force. The underlying mechanism of the VA-separation-based method remains unexplored for the SL-related additive manufacturing, and the best way to use VA separation in the bottom-up based SL process is still unclear. In this paper, a new VA separation design for the bottom-up SL process is presented. A prototype system has been built to study the VA separation mechanism in SL. Experiments on the separation performance under different parameters including vibration frequency, pre-stress level, and exposure area were conducted. Based on the collected separation force data, an analytical model based on the mechanics of fatigue fracture was built. The separation behaviors related to different shape sizes and topologies were also studied and compared. The results showed that the separation force in SL was significantly reduced using the VA-separation-based method. Furthermore, the relationship between the separation force and the separation time conforms to the stress-based fatigue model well. This study provides insights on how to choose process parameters by considering the trade-offs between separation force and building efficiency.2020-01-01T00:00:00ZAirline's Fleet Sizing and Pricing Strategies with Convertible Aircraft under Demand UncertaintyGong, ZhenweiZhang, Fangnihttp://hdl.handle.net/10722/3407432024-03-11T10:46:48Z2024-01-08T00:00:00ZTitle: Airline's Fleet Sizing and Pricing Strategies with Convertible Aircraft under Demand Uncertainty
Authors: Gong, Zhenwei; Zhang, Fangni2024-01-08T00:00:00Z