- Address
- 305-0047 茨城県つくば市千現1-2-1 [アクセス]
研究内容
- Keywords
Oxidation, Toughness, Ferroelasticity
出版物2004年以降のNIMS所属における研究成果や出版物を表示しています。
論文
- Christopher Mercer, Naoe Hosoda. Analysis of Structure and Function of Ladybird Leg and Subsequent Design and Fabrication of a Simplified Leg Structure for Robotic Applications. Biomimetics. 9 [3] (2024) 184 10.3390/biomimetics9030184 Open Access
- MERCER, Christopher. Analysis of Functional Lattice Structures Fabricated via Additive Manufacturing. ふぇらむ. 27 [12] (2022) 936-942
- Christopher Mercer, Thomas Speck, Junyi Lee, Daniel S. Balint, Marc Thielen. Effects of geometry and boundary constraint on the stiffness and negative Poisson's ratio behaviour of auxetic metamaterials under quasi-static and impact loading. International Journal of Impact Engineering. 169 (2022) 104315 10.1016/j.ijimpeng.2022.104315 Open Access
会議録
- MERCER, Christopher, Junyi Lee, Daniel Balint. Mechanical behavior of 3-D printed (green) low thermal expansion lattice structures. Proceedings of the 13th International Conference on Ecomaterials. (2018) 46-51
- M. A. Lafata, L. H. Rettberg, MERCER, Christopher, T. M. Pollock. Sustained Peak Low-Cycle Fatigue in Single Crystals with EQ γ/γ' Coatings. Proceedings of Superalloys 2016. (2016) 405-413
口頭発表
- MERCER, Christopher, SPECK Thomas, LEE Junyi, BALINT Daniel, THIELEN Marc. An Investigation of the Effects of Loading Condition, Boundary Constraint and Geometry Optimization on the Mechanical Response of Auxetic Metamaterials. Asian Congress of Structural and Multidisciplinary Optimization 2022 (ACSMO 2022). 2022
- SPECK Thomas, BALINT Daniel, MERCER, Christopher, BALINT Daniel, LEE Junyi, THIELEN Marc, THIELEN Marc, Investigation of the effects of geomtery and constraint on the mechanical performance of bio-inspired 3-D laser printed auxetic structures. EUROMAT 2019. 2019
- マーサー クリストファー. Behavior of MCrAlY and EQ Bonds Coats under Thermal/Thermomechanical Cycling. MS&T. 2012 招待講演
所属学会
日本航空宇宙学会, Minerals,Metals & Materials Society
構造材料研究センター
Mechanical performance of functional lattices
Low Thermal Expansion, Auxetics, Lattices, Additive Manufacturing, Geometry Optimization
概要
● Mechanically robust complex lattices can be fabricated by additive manufacturing.
● Optimized low thermal expansion lattices exhibit superior mechanical performance compared to the bulk material.
● Geometrically optimized auxetic lattices can possess impact energy absorption capabilities of over 90%.
新規性・独創性
● Fabrication of lattice structures with complex geometries from metallic materials via additive manufacturing (3-D laser printing).
● Evaluation of the mechanical response of the lattices and geometry optimization to maximize lattice mechanical performance.
内容
A 3-D low thermal expansion lattice fabricated from Ti-6Al-4V is shown (left). The mechanical performance of the lattice unit cell under uni-axial compression is also shown. The load increases in a linear-eleastc manner until buckling of the top three struts occurs. This causes the initial sharp load drop. The second load reduction corresponds to buckling and fracture of the lower struts in the unit cell. An optimization plot is shown for lattice stiffness (as a beam). At skew angles (θ) less than 11°, the performance of the lattice is superior to the bulk material.
Auxetic lattices were fabricated from Ti-6Al-4V and stainless-steel powder (right). Specimens with constraining walls were also produced to assess the effect of boundary constraint on the auxetic behavior. Negative Poisson's ratio behavior was established under both quasi-static and impact loading under all conditions (even with the presence of thick constraining walls). Geometry optimization studies (using finite element analysis) have shown that with thin struts or small node thicknesses, such lattices are capable of absorbing over 90% of the energy of an impact.
まとめ
● Mechanically robust complex lattices can be fabricated by additive manufacturing.
● Optimized low thermal expansion lattices exhibit superior mechanical performance compared to the bulk material.
● Geometrically optimized auxetic lattices can possess impact energy absorption capabilities of over 90%.