Barbara Linke

Leveraging Technology for a Sustainable World

The integrated planning of production sequence and logistics transports for vehicle manufacturers is the focus of the research project InterTrans. The aim of the project is to develop sustainable and cost efficient concepts in multi-site production networks with multi-modal supply chain structures. The basic idea is to integrate logistics constraints in production scheduling of a vehicle manufacturer in order to improve inbound and outbound transportation processes in terms of CO2 emissions and transportation costs. The project results show, that the introduction of logistics constraints in production scheduling is possible and that logistics savings can be significant.

Mechanisms in the generation of grinding wheel topography by dressing

For the process of dressing vitrified bonded grinding wheels with diamond tools it has been unknown how the wheel topography is generated. Moreover, the influence of the kinematical dressing parameters on the wheel wear behavior has not been quantified. In the course of this article the grinding wheel was dealt with as a porous ceramic composite. In FEM simulations common dressing forces and usual dressing tool geometries were applied. The results were verified by dressing tests and grinding wheel scratch tests which show the wheel wear mechanisms. The common practice of decreasing the grinding wheel surface roughness by a finishing dressing stroke has to be reconsidered, because previous dressing strokes with higher depths of cut can weaken the grinding wheel structure and lead to an unsteady phase with high grinding wheel wear after dressing.

Review on Grinding Tool Wear With Regard to Sustainability

Manufacturing processes have to become more sustainable. For grinding processes, this means that tool wear and performance need to be critically evaluated in their economic, environmental, and social impact. Tool wear affects several stakeholders. Different wear mechanisms on the grit and bond level lead to a change in tool profile and sharpness. For the user, wear changes tool costs, process stability, and maybe worker safety. Tool manufacturers need tool wear to sell replacements, whereas tool users might not like the higher waste and costs from tool wear but need tool self-sharpening.

Life Cycle Analysis of Grinding

Abrasive unit processes are key technologies to achieve high surface quality and dimensional tolerances with highly stable processes. Life Cycle Inventory provides a basis to evaluate the environmental aspects of unit processes. This paper will provide an integrated analysis of floor-to-floor cycle for product grinding as well as review the state-of-the-art for industrial grinding including cooling lubricants and specific energy. This work discusses existing approaches to evaluate grinding process sustainability and shows the applicability (and limits) of the UPLCI method. The goal is a workable, estimating approach that can be widely used in decisions for energy improvement and product life cycle.

Sustainability Indicators for Grinding Applied to Dressing Strategies

Author(s): Linke, BS | Abstract: Growing environmental awareness leads production engineers to focus increasingly on energy and material efficiency of manufacturing processes. However, only a few holistic approaches have been applied on the manufacturing process level and they often disregard product quality. In this study, sustainability indicators for the discrete manufacturing process of grinding are defined and discussed. Various temporal and spatial boundaries for the sustainability analysis are evaluated with regard to their effect on the results. Selected indicators, here energy and waste intensity, are then used to evaluate different dressing strategies in a case study. This study highlights the challenges in setting the boundaries for a sustainability analysis and stresses the importance of clearly defining these in research papers.

Development of a reliable grinding procedure for ceramic medical instruments

Surgical instruments have to meet strict requirements on functionality and stable performance. The functional properties of scalpels, for example, are mainly dependent on a precise cutting edge geometry and high blade sharpness. To achieve a reliable production of scalpels, it is necessary to establish a holistic understanding of the process chain as well as the interactions of all machining processes. An innovative zirconium oxide offers high toughness and high wear resistance, leading to its use in ophthalmic scalpels. A cooperative project has been conducted by two universities and two industrial partners, funded by the German Federal Ministry of Economics and Technology (BMWi).The project focuses particularly on the grinding process as a controlling factor for the scalpel’s functionality and sharpness. The complex process chain with various interactions of kinematics, vibrations and tool micro-topography was developed for high reliability and efficiency. The performance of in-machine dressing of diamond wheels with diamond form rollers was decisive for scalpel quality.

Sustainability Case Studies

This chapter discusses different case studies on sustainability in the life cycle of abrasive tools. The first study compares the embodied energy of tools with conventional abrasives against tools with superabrasives and discusses further considerations. The second study points to research work on comparing hard turning and grinding. The third and forth studies are about leveraging aspects in speed-stroke grinding and gear grinding.

FEM-Based Simulation of Temperature in Speed Stroke Grinding with 3D Transient Moving Heat Sources

The grinding process is one of the most important finishing processes to obtain high surface quality. Nowadays, grinding is also considered as a high performance process with high material removal rates. Nevertheless, to avoid thermally-induced structural changes poses a major challenge for this manufacturing technology. Until now, the Finite Element Method (FEM) has been widely applied as a proper numerical technique to predict workpiece properties in machining processes. However, actual models in grinding are limited to conventional grinding processes with simple workpiece profiles and low table speeds. In this paper, finite element simulations are expanded to 3-dimensional (3D) models with temperature-dependent material properties and heat source profiles derived from experimental results, i.e. tangential forces. Both temperature simulation and measurement were conducted for deep grinding, pendulum grinding and speed stroke grinding in the table speed range of vw = 12 m/min to 180 m/min and specific material removal rates of Q’w = 40 mm³/mms. Overall, the simulation results show a good agreement with the measured temperature and surface integrity after grinding. This research indicates that a 3D FE model with temperature dependent material properties can predict realistic temperature fields in speed stroke grinding. Therefore, the experiment and measurement costs and time can be reduced by FEM simulation.

Grinding Energy Modeling Based on Friction, Plowing, and Shearing

Journal of Manufacturing Science and Engineering. Received March 30, 2017; Accepted manuscript posted July 13, 2017. doi:10.1115/1.4037239 Copyright (c) 2017 by ASME Grinding energy modeling based on friction, plowing and shearing py ed ite d Barbara S. Linke University of California Davis, Mechanical and Aerospace Engineering Department 1 Shields Ave, Davis, CA 95616 USA bslinke@ucdavis.edu ASME member t N ot Co Ian Garretson University of California Davis, Mechanical and Aerospace Engineering Department 1 Shields Ave, Davis, CA 95616 USA icgarretson@ucdavis.edu Ma nu sc rip Francois Torner University of Kaiserslautern Institute for Measurement and Sensor‐Technology Gottlieb‐Daimler‐Strase 67663 Kaiserslautern Germany torner@mv.uni‐kl.de Ac ce pt ed Joerg Seewig University of Kaiserslautern Institute for Measurement and Sensor‐Technology Gottlieb‐Daimler‐Strase 67663 Kaiserslautern Germany seewig@mv.uni‐kl.de Downloaded From: http://manufacturingscience.asmedigitalcollection.asme.org/pdfaccess.ashx?url=/data/journals/jmsefk/0/ on 07/14/2017 Terms of Use: http://www.asme.org/a

Aesthetics and Gloss of Ground Surfaces: A Review on Measurement and Generation

ASME Journal of Manufacturing Science and Engineering Aesthetics and gloss of ground surfaces – A review on measurement and generation Barbara Linke 1 University of California Davis 1 Shields Ave, Davis, CA 95616, USA bslinke@ucdavis.edu ASME Member Jayanti Das University of California Davis 1 Shields Ave, Davis, CA 95616, USA jydas@ucdavis.edu ABSTRACT Visual appearance of an object significantly influences a consumer’s choice and largely controls the market economy. The perceived quality of products are governed by surface’s optical properties (reflection, refraction, etc.), geometrical properties (roughness, waviness, etc.) and chemical properties (oxide layer formation, thermal variation, etc.). Surface shininess attracts researchers from many different disciplines, in particular manufacturing, metrology, psychology, physiology, and computer science. Unfortunately, there are still huge knowledge gaps on characterizing and appraising shiny surfaces in a reproducible way. This paper introduces the main definitions and physics of shininess and gloss, methods of gloss sensing, and relates these definitions and methods to surface generation by grinding. Automated gloss measurement is difficult in particular for free form surfaces and optical quality is still often evaluated by human workers. Gloss models are often based on the bidirectional reflection distribution function (BRDF) of the surface, but the models are commonly not connected with the manufacturing process. This study proposes to consider the geometrical features (defects, waviness, lay, and roughness) of metal surfaces as well as the physical and chemical features (grain structure and micro layers) to understand surface Corresponding author.