scholarly journals 2084) Study on the Steel Latticed Column(Structure)

1960 ◽  
Vol 66.1 (0) ◽  
pp. 545-548
Author(s):  
Morihisa Fujimoto ◽  
Tsuneo Nanba
Keyword(s):  
Author(s):  
Farid Triawan ◽  
Geraldy Cahya Denatra ◽  
Djati Wibowo Djamari

The study of a thin-walled column structure has gained much attention due to its potential in many engineering applications, such as the crash box of a car. A thin-walled square column usually exhibits high initial peak force, which may become very dangerous to the driver or passenger. To address this issue, introducing some shape patterns, e.g., origami folding pattern, to the column may become a solution. The present work investigates the compressive properties and behavior of a square box column structure which adopts the Miura origami folding pattern. Several test pieces of single-cell Miura origami column with varying folding angle and layer height are fabricated by a 3D printer. The filament is made of Polylactic Acid (PLA), which is a brittle material. Then, compression tests are carried out to understand its compressive mechanical properties and behavior. The results show that introducing a Miura origami pattern to form a thin-walled square column can dramatically lower down the initial peak stress by 96.82% and, at the same time, increase its ductility, which eventually improves the energy absorption capacity by 61.68% despite the brittle fracture behavior.


Coatings ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 529
Author(s):  
Bangfu Wang ◽  
Juan Song

Based on the contact angle prediction model of a traditional square column structure, the prediction models for wettability of a parallelogram square column structure (PSCS) on polymethyl methacrylate (PMMA) surface prepared by femtosecond laser were established. An experiment was conducted to analyze the rationality of the established complete wetting model and incomplete wetting model. It was found that the incomplete wetting prediction model of the square column structure was more in line with the actual situation. For PSCS, the length of both the long and short sides of the boss and the width of the groove exerted an impact on the contact angle prediction results. Under the condition that the length of the long and short sides of the boss remained unchanged and the groove width increased, the contact angle increased under complete wetting and incomplete wetting. In contrast, under the condition that the long side length of the boss and the groove width remained unchanged and the short side length of the boss increased, the contact angle increased under complete wetting but decreased under incomplete wetting. The maximum contact angle reached 135.65°, indicating that PSCS on PMMA surface enhanced the surface hydrophobicity of the material.


Crystals ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 472 ◽  
Author(s):  
Chih-Hao Lin ◽  
Yung-Min Pai ◽  
Chieh-Yu Kang ◽  
Huang-Yu Lin ◽  
Chun-Fu Lee ◽  
...  

This study demonstrates that flexible white LEDs, doped with diffusion particles and with a square column structure, have excellent luminosity, uniformity, and bending reliability. This large area (5 cm × 5 cm) square column flexible device had a smaller thickness (2 mm), and enhancements in both luminous efficiency (29.5%) and uniformity (44.6%) compared to the characteristics of the 6 mm reference sample. Optimization of the reflective layer coating for the square column, flexible white LED was achieved with a higher luminous efficiency (171 lm/w) and uniformity (92%). We designed a novel lightning bolt electrode to improve reliability and bendability. After the bending test, the blue flexible LED had a lower bending diameter (10 mm) but more bending circles (increased to 2000 times.


Author(s):  
Shenggang Guo ◽  
Zhiling Yuan ◽  
Fenghe Wu ◽  
Yongxin Li ◽  
Shaoshuai Wang ◽  
...  

The selection of biomimetic prototypes mostly depends on the subjective observation of a designer. This research uses TRIZ to explore some inferential steps in bionic design of the heavy machine tool column. Conflict resolution theory of TRIZ is applied to describe improved and deteriorated parameters and a contradiction matrix is used to obtain recommended inventive principles. A reference table of solutions corresponding to the biological phenomenon and TRIZ solutions is formed to expedite retrieving the biomimetic object. Based on the table, herbaceous hollow stem is selected to imitate column structure. Four kinds of plant are chosen from the biological database. To select the best from four candidates, a bionic ideality evaluation index is proposed based on similarity analysis and ideality evaluation theory in TRIZ. Thus, the bionic effect can be described and compared quantitatively. Bionic configuration is then evolved concerning manufacturing requirements. Size optimization of stiffener thicknesses is implemented finally, and satisfactory results of the lightweight effect is obtained.


2014 ◽  
Vol 84 ◽  
pp. 110-126 ◽  
Author(s):  
Wilken-Jon von Appen ◽  
Robert S. Pickart ◽  
Kenneth H. Brink ◽  
Thomas W.N. Haine

Author(s):  
Dongdong Wang ◽  
Pinkang Xie ◽  
Lingming Fang

A consistent asymptotic expansion multiscale formulation is presented for analysis of the heterogeneous column structure, which has three dimensional periodic reinforcements along the axial direction. The proposed formulation is based upon a new asymptotic expansion of the displacement field. This new multiscale displacement expansion has a three dimensional form, more specifically, it takes into account the axial periodic property but simultaneously keeps the cross section dimensions in the global scale. Thus, this formulation inherently reflects the characteristics of the column structure, i.e., the traction free condition on the circumferential surfaces. Subsequently, the global equilibrium problem and the local unit cell problem are consistently derived based upon the proposed asymptotic displacement field. It turns out that the global homogenized problem is the standard axial equilibrium equation, while the local unit cell problem is completely three dimensional which is subjected to the periodic boundary condition on axial surfaces as well as the traction free condition on circumferential surfaces of the unit cell. Thereafter, the variational formulation and finite element discretization of the unit cell problem are discussed. The effectiveness of the present formulation is illustrated by several numerical examples.


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