Propulsion system development requires new, more affordable manufacturing techniques and technologies in a constrained budget environment, while future in-space applications will require in-space manufacturing and assembly of parts and systems. Marshall is advancing cuttingedge commercial capabilities in additive and digital manufacturing and applying them to aerospace challenges. The Center is developing the standards by which new manufacturing processes and parts will be tested and qualified. Rapidly evolving digital tools, such as additive manufacturing, are the leading edge of a revolution in the design and manufacture of space systems that enables rapid prototyping and reduces production times. Marshall has unique expertise in leveraging new digital tools, 3D printing, and other advanced manufacturing technologies and applying them to propulsion systems design and other aerospace materials to meet NASA mission and industry needs. Marshall is helping establish the standards and qualifications “from art to part” for the use of these advanced techniques and the parts produced using them in aerospace or elsewhere in the U.S. industrial base.

Additive manufacturing

https://spiral.imperial.ac.uk/bitstream/10044/1/73026/9/1-s2.0-S0264127519306021-main.pdf

Review on design and structural optimisation in additive manufacturing: Towards next-generation lightweight structures

VOLUME ONE: CLASSICAL AND CONTEMPORARY STUDIES Banana Time: Job Satisfaction and Informal Interaction - Donald Roy Perceptions and Methods in Men Who Manage - Melville Dalton Men and Women of the Corporation - Rosabeth Kanter Manufacturing Consent - Michael Burawoy Breakfast at Spiro's: Dramaturgy and Dominance - Michael Rosen The World of Corporate Managers - Robert Jackall Engineering Humour: Masculinity Joking and Conflict in Shop-Floor Relations - David Collinson Extract from Crafting Selves: Power Gender and Discourses of Identity in a Japanese Workplace - Dorinne Kondo Engineering Culture: Control and Commitment in a High-Tech Corporation - Gideon Kunda Theorizing Managerial Work: A Pragmatic Pluralist Approach to Interdisciplinary Research - Tony Watson Rational Choice Situated Action and the Social Control of Organizations: The Challenger Launch Decision - Diane Vaughan Strategizing as Lived Experience and Strategists - Dalvir Samra-Fredericks Power Control and Resistance in 'The Factory that Time Forgot' - Mahmoud Ezzamel et al. Extract from Talking about Machines: An Ethnography of a Modern Job - Julian Orr Extract from The Business of Talk: Organizations in Action - Diedre Boden Extract from Investigating Small Firms: Nice Work? - Ruth Holliday Narrative Interviewing and Narrative Analysis in a Study of a Cross-Border Merger - Anne-Marie Soderberg Speech Timing and Spacing: The Phenomenon of Organizational Closure - Francois Cooren and Gail T. Fairhurst, VOLUME TWO: METHODS APPROACHES TECHNIQUES: GUIDES AND EXEMPLARS The Infeasibility of Invariant Laws in Management Studies: A Reflective Dialogue in Defence of Case Studies - Tsuyoshi Numagami The Interview: From Neutral Stance to Political Involvement - Andrea Fontana and James Frey Rethinking Observation: From Method to Context - Michael Agrosino et al. Notes on (Field) notes - James Clifford The Textual Approach: Risk and Blame in Disaster Sensemaking - Robert Gephart Triangulation in Organizational Research: A Re-presentation - Julie Wolfram Cox and John Hassard The Storytelling Organization: A Study of Performance in an Office Supply Firm - David Boje Semiotics and the Study of Occupational and Organizational Cultures - Stephen Barley The Use of Grounded Theory for the Qualitative Analysis of Organizational Behaviour - Barry Turner Reflecting on the Strategic Use of CAQDAS to Manage and Report on the Qualitative Research Process - Mark Wickham and Megan Woods Longitudinal Field Research on Change - Andrew Pettigrew Historical Perspectives in Organization Studies: Factual Narrative and Archeo-Genealogical - Michael Rowlinson Action Research: Explaining the Diversity - Cathy Cassell and Phil Johnson Photography and Voice in Critical Qualitative Management Research - Samantha Warren Moments Mixed Methods and Paradigm Dialogues - Norman Denzin VOLUME THREE: PRACTICES AND PREOCCUPATIONS Extract from The Discipline and Practice of Qualitative Research - Norman Denzin and Yvonna Lincoln Learning to Be a Qualitative Management Researcher - Catherine Cassell et al. Getting In Getting On Getting Out and Getting Back - David Buchanan et al. Reflections on the Researcher-Researched Relationship: A Woman Interviewing Men - Terry Arendell Real-Time Reflexivity: Prods to Reflection - Karl Weick Towards an Integrative Reflexivity in Organizational Research - Leah Tomkins and Virginia Eatough Appealing Work: An Investigation of How Ethnographic Texts Convince - Karen Golden-Biddle and Karen Locke The Philosophy and Politics of Quality in Qualitative Organizational Research - John Amis and Michael Silk Objectivity and Reliability in Qualitative Analysis: Realist Contextualist and Radical Constructionist Epistemologies - Anna Madill et al. Whatever Happened to Organizational Ethnography: A Review of the Field of Organizational Ethnography and Anthropological Studies - S.P. Bate Working with Pluralism: Determining Quality in Qualitative Research - Mark Easterby-Smith, Karen Golden-Biddle and Karen Locke The Role of the Researcher: An Analysis of Narrative Position in Organisation Theory - Mary Jo Hatch The Professional Apprentice: Observations of Fieldwork Roles in Two Organizational Settings - John Van Maanen and Deborah Kolb In Defense of Being "Native": The Case for Insider Academic Research - Teresa Brannick and David Coghlan Ethics and Ethnography - Robert Dingwall Extract from Qualitative Methods in Management Research - Evert Gummesson Making Sense as a Personal Process - Judi Marshall My Affair with the "Other": Identity Journeys across the Research-Practice Divide - Laura Empson VOLUME FOUR: CHALLENGES AND PROSPECTS Secrecy and Disclosure in Fieldwork - Richard Mitchell Organization Science as Social Construction: Postmodern Potentials - Kenneth Gergen and Tojo Joseph Thatchenkerry Farewell to Criteriology - Thomas Schwandt Reflexive Inquiry in Organizational Research: Questions and Possibilities - Ann Cunliffe The Action Turn: Towards a Transformational Social Science - Peter Reason and William Torbert Signing My Life Away? Researching Sex and Organization - Joanna Brewis Evaluating Qualitative Management Research: Towards a Contingent Criteriology - Phil Johnson et al. Postcolonialism and the Politics of Qualitative Research in International Business - Gavin Jack and Robert Westwood Organization Studies and Epistemic Coloniality in Latin America: Thinking Otherness from the Margins - Eduardo Ibbaro-Colado Fitting Oval Pegs into Round Holes: Tensions in Evaluating and Publishing Qualitative Research in Top-Tier North American Journals - Michael Pratt Hegemonic Academic Practices: Experiences of Publishing from the Periphery - Susan Merilainen et al., Case Study as Disciplinary Convention: Evidence from International Business Journals - Rebecca Piekkari, Catherine Welsh and Eriikka Paavilainen Managerialism and Management Research: Would Melville Dalton Get a Job Today? - Emma Bell Ways of constructing research questions: gap-spotting or problematization? - Jorgen Sandberg and Mats Alvesson

Challenges and prospects

Innovative honeycomb-based structures have been paid substantial attention in recent years due to their superb mechanical performances and specific functions. The presented study made acomprehensive overview on the development of the innovative honeycomb-based structures in the past two decades, including filled-type, embedded, tandem, hierarchical, auxetics with Negative Poisson's Ratio (NPR), etc. Mechanical performances of these structures were commented with advantages and disadvantages, related on their geometric configurations, mechanical performance and dynamic response, respectively. The challenges as well as future directions were also analyzed. The achievements provide significant guidelines in designing of new generation light-weight honeycomb-based structures.

Recent advances in novel metallic honeycomb structure

Novel engineered wood and bamboo composites for structural applications: State-of-art of manufacturing technology and mechanical performance evaluation

Effective elastic properties of periodic hexagonal honeycombs

Additive manufacturing is a fabrication technology that is rapidly revolutionising the manufacturing and construction sectors. In this paper, a review of various prototyping technologies for printing cementitious materials and selected 3D printing techniques are presented in detail. Benchmark examples are provided to compare three well-known printing techniques; inkjet printing (binder jetting), selected laser sintering (SLS) and extrusion printing (FDM). A comprehensive search in the literature was conducted to identify various mix designs that could be employed when printing cementitious materials. Aspects of concrete mix design are described, and some new experiments are conducted to analyse the printability of new mixes by the authors. Future research in the area of the rheology of cementitious materials and its relationship with the structural performance of finished concretes are highlighted.

/pdf/review-of-emerging-additive-manufacturing-technologies-in-3d-p0es99194o.pdf

Review of emerging additive manufacturing technologies in 3D printing of cementitious materials in the construction industry

Additive manufacturing technologies offer new ways to fabricate cellular materials with composite cell walls, mimicking the structure and mechanical properties of woods. However, materials limitations and a lack of design tools have confined the usefulness of 3D printed cellular materials. We develop new carbon fiber reinforced, epoxy inks for 3D printing which result in printed materials with longitudinal Young's modulus up to 57 GPa (exceeding the longitudinal modulus of wood cell wall material). To guide the design of hierarchical cellular materials, we developed a parameterized, multi-scale, finite element model. Computational homogenization based on finite element simulations at multiple length scales is employed to obtain the elastic properties of the material at multiple length scales. Parameters affecting the elastic response of cellular composites, such as the volume fraction, orientation distribution, and aspect ratio of fibers within the cell walls as well as the cell geometry and relative density are included in the model. To validate the model, experiments are conducted on both solid carbon fiber/epoxy composites and cellular structures made from them, showing excellent agreement with computational multi-scale model predictions, both at the cell-wall and at the cellular-structure levels. Using the model, cellular structures are designed and experimentally shown to achieve a specific stiffness nearly as high as that observed in balsa wood. The good agreement between the multi-scale model predictions and experimental data provides confidence in the practical utility of this model as a tool for designing novel 3D cellular composites with unprecedented specific elastic properties.

http://iopscience.iop.org/article/10.1088/1748-3190/aa6028/pdf

Sardar Malek

Papers

Effective elastic properties of periodic hexagonal honeycombs

Review of emerging additive manufacturing technologies in 3D printing of cementitious materials in the construction industry

Lightweight 3D cellular composites inspired by balsa.

A differential approach to finite element modelling of isotropic and transversely isotropic viscoelastic materials

Multi-scale modelling of elastic properties of balsa