scholarly journals ROTATIONAL STIFFNESS OF STEEL CONNECTIONS FOR TIMBER LATTICE SHELL IN NEGATIVE OUT-OF-PLANE AND IN-PLANE DIRECTIONS

2019 ◽  
Vol 84 (760) ◽  
pp. 831-841
Author(s):  
Shun NAKAJIMA ◽  
Yoshihiro YAMAZAKI ◽  
Hiroyasu SAKATA ◽  
Toru TAKEUCHI ◽  
Hiroaki HARADA ◽  
...  
Keyword(s):  
Rotational Stiffness ◽  
Steel Connections ◽  
Out Of Plane ◽  
Lattice Shell

scholarly journals ELASTIC BUCKLING STRENGTH OF TIMBER LATTICE SHELL WITH STEEL CONNECTIONS CONSIDERING ROTATIONAL STIFFNESS

2019 ◽  
Vol 84 (762) ◽  
pp. 1081-1091
Author(s):  
Shun NAKAJIMA ◽  
Yuki TERAZAWA ◽  
Toru TAKEUCHI ◽  
Toshiyuki OGAWA ◽  
Yoshihiro YAMAZAKI ◽  
...  
Keyword(s):  
Elastic Buckling ◽  
Rotational Stiffness ◽  
Buckling Strength ◽  
Steel Connections ◽  
Lattice Shell

scholarly journals ROTATIONAL STIFFNESS AND BENDING STRENGTH OF STEEL CONNECTIONS IN TIMBER LATTICE SHELL

2018 ◽  
Vol 83 (746) ◽  
pp. 577-587 ◽  
Author(s):  
Hiroaki HARADA ◽  
Shun NAKAJIMA ◽  
Yoshihiro YAMAZAKI ◽  
Ryota MATSUI ◽  
Kenichi HAYASHI ◽  
...  
Keyword(s):  
Bending Strength ◽  
Rotational Stiffness ◽  
Steel Connections ◽  
Lattice Shell

Flexural Properties of Buckling-Restrained Brace Connections

2018 ◽  
Vol 763 ◽  
pp. 916-923
Author(s):  
Ben Sitler ◽  
Toru Takeuchi ◽  
Ryota Matsui
Keyword(s):  
Global Stability ◽  
Analytical Methods ◽  
Flexural Properties ◽  
Rotational Stiffness ◽  
Transverse Beam ◽  
Buckling Restrained Brace ◽  
Highly Effective ◽  
Buckling Restrained Braces ◽  
Out Of Plane ◽  
Large Peak

Buckling-restrained braces (BRBs) achieve large peak and cumulative ductility capacities by restricting yielding to an encased core, while maintaining global stability. However, stability is often governed by the connections and is sensitive to the end fixity provided by the adjacent framing and gusset, and flexural continuity between the neck and restrainer. This paper presents simple analytical methods to determine the flexural properties of these key components. Full-depth gusset stiffeners are found to be highly effective in increasing the out-of-plane rotational stiffness (KRg), equivalent to doubling the thickness. An equivalent connection is proposed to account for the adjacent framing (KRf), but this may be neglected if KRf > 10∙KRg. This is typically satisfied if a diaphragm slab and transverse beam are provided, but may exceed beam torsional bracing requirements. The restrainer end moment transfer capacity is extended to mortar-filled RHS restrainers, confirming that neck insert ratios of Lin/Bn > 2.0 are required for full continuity.

scholarly journals Stability of trusses by graphic statics

2021 ◽  
Vol 8 (6) ◽  
pp. 201970
Author(s):  
Allan McRobie ◽  
Cameron Millar ◽  
William F. Baker
Keyword(s):  
Axial Force ◽  
Graphical Representation ◽  
Graphical Method ◽  
Three Dimensional ◽  
Weighted Sum ◽  
Two Dimensional ◽  
Rotational Stiffness ◽  
Graphic Statics ◽  
Out Of Plane ◽  
Pinned Joints

This paper presents a graphical method for determining the linearized stiffness and stability of prestressed trusses consisting of rigid bars connected at pinned joints and which possess kinematic freedoms. Key to the construction are the rectangular areas which combine the reciprocal form and force diagrams in the unified Maxwell–Minkowski diagram. The area of each such rectangle is the product of the bar tension and the bar length, and this corresponds to the rotational stiffness of the bar that arises due to the axial force that it carries. The prestress stability of any kinematic freedom may then be assessed using a weighted sum of these areas. The method is generalized to describe the out-of-plane stability of two-dimensional trusses, and to describe three-dimensional trusses in general. The paper also gives a graphical representation of the ‘product forces’ that were introduced by Pellegrino and Calladine to describe the prestress stability of trusses.

scholarly journals Initial rotational stiffness of minor-axis flush end-plate connections

2018 ◽  
Vol 10 (1) ◽  
pp. 168781401774539
Author(s):  
Jianrong Pan ◽  
Shizhe Chen ◽  
Zhan Wang ◽  
Hui Lu
Keyword(s):  
Finite Element ◽  
Minor Axis ◽  
Bottom Flange ◽  
Rotational Stiffness ◽  
Bending Deformation ◽  
End Plate ◽  
Out Of Plane ◽  
Plane Bending ◽  
Plate Connections ◽  
Plate Connection

The semi-rigid performance of minor-axis connections is important in the study of overall framework. Experiments were conducted on minor-axis flush end-plate connections under a monotonic load. Numerical simulations were carried out using the finite-element package ABAQUS and compared with the experimental results. The initial rotational stiffness of the connection was calculated using the equivalent T-stub in tension and EC3 component method, and the calculated veracity is discussed. The results show that under the action of a negative bending moment, the failure modes of the minor-axis flush end-plate connection are the out-of-plane bending deformation of the end-plate, local buckling of the bottom flange of the beam, and bending deformation of the bolts. The minor-axis flush end-plate connection is a typical semi-rigid connection. However, the deformations of the flush end-plate could not be accurately calculated using the equivalent T-stub in the tension of EC3 methods. The initial rotational stiffness calculated using the method was much larger than that obtained using the experiment and finite-element analysis. The equivalent simulation is not appropriate if the out-of-plane bending stiffness of the flush end-plate is not obtained accurately.

Grain separation enhanced magnetic coercivity in Pt/Co multilayers.

1993 ◽  
Vol 51 ◽  
pp. 1038-1039 ◽  
Author(s):  
G.A. Bertero ◽  
R. Sinclair
Keyword(s):  
Remanent Magnetization ◽  
Strong Influence ◽  
Uniaxial Anisotropy ◽  
Magnetic Coupling ◽  
Recording Media ◽  
Magnetic Media ◽  
Signal To Noise ◽  
Out Of Plane ◽  
Longitudinal Recording ◽  
The Relationship

Pt/Co multilayers displaying perpendicular (out-of-plane) magnetic anisotropy and 100% perpendicular remanent magnetization are strong candidates as magnetic media for the next generation of magneto-optic recording devices. The magnetic coercivity, Hc, and uniaxial anisotropy energy, Ku, are two important materials parameters, among others, in the quest to achieving higher recording densities with acceptable signal to noise ratios (SNR). The relationship between Ku and Hc in these films is not a simple one since features such as grain boundaries, for example, can have a strong influence on Hc but affect Ku only in a secondary manner. In this regard grain boundary separation provides a way to minimize the grain-to-grain magnetic coupling which is known to result in larger coercivities and improved SNR as has been discussed extensively in the literature for conventional longitudinal recording media.We present here results from the deposition of two Pt/Co/Tb multilayers (A and B) which show significant differences in their coercive fields.

Anisotropy of Nanoindentation – a tool for the determination of nanocrystal orientation ?

2003 ◽  
Vol 779 ◽  
Author(s):  
David Christopher ◽  
Steven Kenny ◽  
Roger Smith ◽  
Asta Richter ◽  
Bodo Wolf ◽  
...  
Keyword(s):  
Crystal Surface ◽  
Scanning Force Microscopy ◽  
Depth Range ◽  
Dislocation Loops ◽  
Force Microscopy ◽  
Pile Up ◽  
Out Of Plane ◽  
Scanning Force ◽  
Dynamics Simulations

AbstractThe pile up patterns arising in nanoindentation are shown to be indicative of the sample crystal symmetry. To explain and interpret these patterns, complementary molecular dynamics simulations and experiments have been performed to determine the atomistic mechanisms of the nanoindentation process in single crystal Fe{110}. The simulations show that dislocation loops start from the tip and end on the crystal surface propagating outwards along the four in-plane <111> directions. These loops carry material away from the indenter and form bumps on the surface along these directions separated from the piled-up material around the indenter hole. Atoms also move in the two out-of-plane <111> directions causing propagation of subsurface defects and pile-up around the hole. This finding is confirmed by scanning force microscopy mapping of the imprint, the piling-up pattern proving a suitable indicator of the surface crystallography. Experimental force-depth curves over the depth range of a few nanometers do not appear smooth and show distinct pop-ins. On the sub-nanometer scale these pop-ins are also visible in the simulation curves and occur as a result of the initiation of the dislocation loops from the tip.

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