Tool Technology for Lightweight Structures in 3-D Hybrid Designs

Textiles are perishables in the archaeological record unless specific environmental conditions are met. Fortunately, the textile tools used in their manufacture can provide a wealth of information and via experimental archaeology make visible to an extent what has been lost. The article presents and discusses the results obtained in a research project focused on textile tool technologies and identities in the context of settler and indigenous peoples, at select archaeological sites in South Italy and Sicily in the Archaic and Early Classical periods, with an emphasis on loom weights. Despite a common functional tool technology, the examined loom weights reveal an intriguing inter-site specificity, which, it is argued, is the result of hybrid expressions embedded in local traditions. Experimental archaeology testing is applied in the interpretation of the functional qualities of this common artefact.

Download Full-text

Investigation of Energy-Absorbing Properties of a Bio-Inspired Structure

Metals ◽

10.3390/met11060881 ◽

2021 ◽

Vol 11 (6) ◽

pp. 881

Author(s):

Adrian Dubicki ◽

Izabela Zglobicka ◽

Krzysztof J. Kurzydłowski

Keyword(s):

Absorption Capacity ◽

Compression Tests ◽

Element Analysis ◽

Lightweight Structures ◽

New Energy ◽

Absorbing Material ◽

Lightweight Structure ◽

3D Printed ◽

Deformation Force ◽

Energy Absorbing

Numerous engineering applications require lightweight structures with excellent absorption capacity. The problem of obtaining such structures may be solved by nature and especially biological structures with such properties. The paper concerns an attempt to develop a new energy-absorbing material using a biomimetic approach. The lightweight structure investigated here is mimicking geometry of diatom shells, which are known to be optimized by nature in terms of the resistance to mechanical loading. The structures mimicking frustule of diatoms, retaining the similarity with the natural shell, were 3D printed and subjected to compression tests. As required, the bio-inspired structure deformed continuously with the increase in deformation force. Finite element analysis (FEA) was carried out to gain insight into the mechanism of damage of the samples mimicking diatoms shells. The experimental results showed a good agreement with the numerical results. The results are discussed in the context of further investigations which need to be conducted as well as possible applications in the energy absorbing structures.

Download Full-text

Zero-Power Latching, Large-Stroke, High-Precision Linear Microactuator for Lightweight Structures in Space

19th IEEE International Conference on Micro Electro Mechanical Systems ◽

10.1109/memsys.2006.1627902 ◽

2006 ◽

Cited By ~ 4

Author(s):

R. Toda ◽

Eui-Hyeok Yang

Keyword(s):

High Precision ◽

Lightweight Structures

Download Full-text

ON THE TIMING OF THE OLD COPPER COMPLEX IN NORTH AMERICA: A COMPARISON OF RADIOCARBON DATES FROM DIFFERENT ARCHAEOLOGICAL CONTEXTS

Radiocarbon ◽

10.1017/rdc.2021.7 ◽

2021 ◽

pp. 1-19

Author(s):

David P Pompeani ◽

Byron A Steinman ◽

Mark B Abbott ◽

Katherine M Pompeani ◽

William Reardon ◽

...

Keyword(s):

Native American ◽

Lake Sediment ◽

Copper Complex ◽

Lake Superior ◽

Copper Mining ◽

Radiocarbon Dates ◽

Copper Mines ◽

Tool Technology ◽

High Lead ◽

Old Copper Complex

ABSTRACT The Old Copper Complex (OCC) refers to the production of heavy copper-tool technology by Archaic Native American societies in the Lake Superior region. To better define the timing of the OCC, we evaluated 53 (eight new and 45 published) radiocarbon (14C) dates associated with copper artifacts and mines. We compared these dates to six lake sediment-based chronologies of copper mining and annealing in the Michigan Copper District. 14C dates grouped by archaeological context show that cremation remains, and wood and cordage embedded in copper artifacts have ages that overlap with the timing of high lead (Pb) concentrations in lake sediment. In contrast, dates in stratigraphic association and from mines are younger than those from embedded and cremation materials, suggesting that the former groups reflect the timing of processes that occurred post-abandonment. The comparatively young dates obtained from copper mines therefore likely reflect abandonment and infill of the mines rather than active use. Excluding three anomalously young samples, the ages of embedded organic material associated with 15 OCC copper artifacts range from 8500 to 3580 cal BP, confirming that the OCC is among the oldest known metalworking societies in the world.

Download Full-text

An Additively Manufactured Titanium Alloy in the Focus of Metallography

Practical Metallography ◽

10.1515/pm-2020-0001 ◽

2021 ◽

Vol 58 (1) ◽

pp. 4-31

Author(s):

C. Fleißner-Rieger ◽

T. Pogrielz ◽

D. Obersteiner ◽

T. Pfeifer ◽

H. Clemens ◽

...

Keyword(s):

Additive Manufacturing ◽

Microstructural Analysis ◽

Microstructural Characterization ◽

Melting Process ◽

Manufacturing Processes ◽

Ingot Metallurgy ◽

Lightweight Structures ◽

Metallographic Preparation ◽

Fine Structures ◽

Specific Material

Abstract Additive manufacturing processes allow the production of geometrically complex lightweight structures with specific material properties. However, by contrast with ingot metallurgy methods, the manufacture of components using this process also brings about some challenges. In the field of microstructural characterization, where mostly very fine structures are analyzed, it is thus indispensable to optimize the classic sample preparation process and to furthermore implement additional preparation steps. This work focuses on the metallography of additively manufactured Ti‑6Al‑4V components produced in a selective laser melting process. It offers a guideline for the metallographic preparation along the process chain of additive manufacturing from the metal powder characterization to the macro- and microstructural analysis of the laser melted sample. Apart from developing preparation parameters, selected etching methods were examined with regard to their practicality.

Download Full-text

Profile beams with adaptive bending–twist coupling by adjustable shear centre location

Journal of Intelligent Material Systems and Structures ◽

10.1177/1045389x12458040 ◽

2012 ◽

Vol 24 (3) ◽

pp. 334-346 ◽

Cited By ~ 10

Author(s):

Wolfram Raither ◽

Andrea Bergamini ◽

Paolo Ermanni

Keyword(s):

Flexural Rigidity ◽

Variable Stiffness ◽

Structural Elements ◽

Lightweight Structures ◽

Load Carrying ◽

Structural Concept ◽

Simulation And Experiment ◽

Coupling Stiffness ◽

Shear Centre

Semi-active structural elements based on variable stiffness represent a promising approach to the solution of the conflict of requirements between load-carrying capability and shape adaptivity in morphing lightweight structures. In the present work, a structural concept with adaptive bending–twist coupling aiming at a broad adjustment range of coupling stiffness while maintaining high flexural rigidity is investigated by analysis, simulation and experiment.

Download Full-text

Characterizing material liberation of multi-material lightweight structures from shredding experiments and finite element simulations

Minerals Engineering ◽

10.1016/j.mineng.2021.107142 ◽

2021 ◽

Vol 172 ◽

pp. 107142

Author(s):

Magdalena Heibeck ◽

Martin Rudolph ◽

Niels Modler ◽

Markus Reuter ◽

Angelos Filippatos

Keyword(s):

Finite Element ◽

Finite Element Simulations ◽

Lightweight Structures

Download Full-text

The Teaching of Machine-Tool Technology at University Level

Proceedings of the Institution of Mechanical Engineers ◽

10.1243/pime_proc_1970_185_016_02 ◽

1970 ◽

Vol 185 (1) ◽

pp. 83-93 ◽

Cited By ~ 1

Author(s):

F. Koenigsberger

Keyword(s):

Machine Tool ◽

Internal Combustion Engines ◽

Manufacturing System ◽

Full Time ◽

Combustion Engines ◽

Human Aspects ◽

University Level ◽

Time Courses ◽

Tool Technology ◽

Specialized Subject

In this paper the problems of introducing the teaching of a specialized subject into undergraduate courses are discussed with particular reference to the specific features of machine-tool technology. These cover the facts that the machine must be considered as part of an overall manufacturing system, so that the concept of performance differs from that encountered in other types of machinery such as internal-combustion engines, and that technological, economic, and human aspects must also be considered. Comparisons are made between Continental, particularly German, practice and present practice in some British universities. Some typical approaches to the organization of postgraduate full-time courses and short-term specialized courses are given. Finally, a comparison is made between the employment of university trained engineers in the machine-tool manufacturing and using industries in Great Britain and in Germany.

Download Full-text