Capillary control of collapse in soft composite columns

To expand the application of bamboo as a building material, a new type of box section composite column that combined bamboo and steel was considered in this paper. The creep characteristics of eight bamboo-steel composite columns with different parameters were tested to evaluate the effects of load level, section size and interface type under long-term loading. Then, the deformation development of the composite column under long-term loading was observed and analyzed. In addition, the creep-time relationship curve and the creep coefficient were created. Furthermore, the creep model of the composite column was proposed based on the relationship between the creep of the composite column and the creep of bamboo, and the calculated value of creep was compared with the experimental value. The experimental results showed that the creep development of the composite column was fast at first, and then became stable after about 90 days. The creep characteristics were mainly affected by long-term load level and section size. The creep coefficient was between 0.160 and 0.190. Moreover, the creep model proposed in this paper was applicable to predict the creep development of bamboo-steel composite columns. The calculation results were in good agreement with the experimental results.

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Stability and failure of compressed thin‐walled composite columns using experimental tests and advanced numerical damage models

International Journal for Numerical Methods in Engineering ◽

10.1002/nme.6757 ◽

2021 ◽

Author(s):

Patryk Rozylo

Keyword(s):

Experimental Tests ◽

Composite Columns ◽

Damage Models ◽

Thin Walled

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Analytical solution and evolution process of gas permeability coefficient on typical hard-soft composite coal seam

Arabian Journal of Geosciences ◽

10.1007/s12517-021-07774-0 ◽

2021 ◽

Vol 14 (15) ◽

Author(s):

Yikuo Wang ◽

Hongbao Zhao ◽

Tong Wu ◽

Lei Wang ◽

Jinyu Li ◽

...

Keyword(s):

Analytical Solution ◽

Coal Seam ◽

Permeability Coefficient ◽

Gas Permeability ◽

Evolution Process ◽

Soft Composite

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Improving the Actuation Speed and Multi-Cyclic Actuation Characteristics of Silicone/Ethanol Soft Actuators

Actuators ◽

10.3390/act9030062 ◽

2020 ◽

Vol 9 (3) ◽

pp. 62 ◽

Cited By ~ 1

Author(s):

Boxi Xia ◽

Aslan Miriyev ◽

Cesar Trujillo ◽

Neil Chen ◽

Mark Cartolano ◽

...

Keyword(s):

Thermal Conductivity ◽

Short Term Memory ◽

Conductive Filler ◽

Thermally Driven ◽

Thermally Conductive ◽

Ethanol Evaporation ◽

Long Short Term Memory ◽

Soft Actuators ◽

Robotic Applications ◽

Soft Composite

The actuation of silicone/ethanol soft composite material-actuators is based on the phase change of ethanol upon heating, followed by the expansion of the whole composite, exhibiting high actuation stress and strain. However, the low thermal conductivity of silicone rubber hinders uniform heating throughout the material, creating overheated damaged areas in the silicone matrix and accelerating ethanol evaporation. This limits the actuation speed and the total number of operation cycles of these thermally-driven soft actuators. In this paper, we showed that adding 8 wt.% of diamond nanoparticle-based thermally conductive filler increases the thermal conductivity (from 0.190 W/mK to 0.212 W/mK), actuation speed and amount of operation cycles of silicone/ethanol actuators, while not affecting the mechanical properties. We performed multi-cyclic actuation tests and showed that the faster and longer operation of 8 wt.% filler material-actuators allows collecting enough reliable data for computational methods to model further actuation behavior. We successfully implemented a long short-term memory (LSTM) neural network model to predict the actuation force exerted in a uniform multi-cyclic actuation experiment. This work paves the way for a broader implementation of soft thermally-driven actuators in various robotic applications.

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