Axial compression deformability and energy absorption of hierarchical thermoplastic composite honeycomb graded structures

2020 ◽  
Vol 254 ◽  
pp. 112851
Author(s):  
Houchang Liu ◽  
Liming Chen ◽  
Jinjun Cao ◽  
Liliang Chen ◽  
Bing Du ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Thermoplastic Composite ◽  
Graded Structures

Energy Absorption of Spruce Wood under Three Kinds of Quasi-Static Compression Conditions

2011 ◽  
Vol 250-253 ◽  
pp. 3-9 ◽  
Author(s):  
Wei Zhou Zhong ◽  
Xi Cheng Huang ◽  
Zhi Ming Hao ◽  
Ruo Ze Xie ◽  
Gang Chen
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Failure Modes ◽  
Cell Structure ◽  
Wood Fiber ◽  
Absorption Efficiency ◽  
Compression Process ◽  
Static Compression ◽  
Spruce Wood ◽  
Energy Absorption Efficiency

The curves of stress versus strain along spruce wood axial, radial and tangential directions are gained by static compression experiments. Moisture content and density of the spruce wood are 12.72% and 413 kg/m3respectively. The results indicate that spruce compression process includes elastic, yield and compaction phases. Failure modes of spruce subjected to axial compression are fiber buckling and wrinkle. And failure modes under radial or tangential compression are wood fiber slippage and delamination. Axial compression yield strength is about nine times as that of radial and tangential compression. Radial and tangential compression yield strengths are almost equal. Energy absorption efficiency and ideality energy absorption efficiency of spruce along different loading directions are analyzed. And theory analytic solution to single wood cell buckling under axial compression is done. The obtained expression shows that the mean limit loading is relative to yield stress, cell structure dimension and wrinkle length for complete wrinkle cases.

Energy Absorption of All-Metallic Corrugated Sandwich Cylindrical Shells Subjected to Axial Compression

2020 ◽  
Vol 87 (12) ◽  
Author(s):  
Pengbo Su ◽  
Bin Han ◽  
Mao Yang ◽  
Zhongnan Zhao ◽  
Feihao Li ◽  
...  
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
High Speed ◽  
Impact Load ◽  
Cylindrical Shells ◽  
Dynamic Effect ◽  
Absorption Capacity ◽  
Amplification Coefficient ◽  
Displacement Curve ◽  
The Impact

Abstract The energy adsorption properties of all-metallic corrugated sandwich cylindrical shells (CSCSs) subjected to axial compression loading were investigated by the method combining experiments, finite element (FE) simulations, and theoretical analysis. CSCS specimens manufactured using two different methods, i.e., high-speed wire-cut electric discharge machining (HSWEDM) and extrusion, were tested under axial compression. While specimens fabricated separately by HSWEDM and extrusion both exhibited a stable crushing behavior, the extruded ones were much more applicable as lightweight energy absorbers because of their good energy absorption capacity, repeatability, and low cost. The numerically simulated force–displacement curve and the corresponding deformation morphologies of the CSCS compared well with those obtained from experiments. The specific folding deformation mode was revealed from both experiments and simulations. Subsequently, based upon the mode of folding deformation, a theoretical model was established to predict the mean crushing force of the CSCS construction. It was demonstrated that CSCSs with more corrugated units, smaller value of tc/tf and W/Ro could dissipate more impact energy. Such sandwich cylindrical shells exhibited better energy absorption than monolithic cylindrical shells, with an increase of at least 30%. Ultimately, the dynamic effect under the impact load was further evaluated. The dynamic amplification coefficient of CSCS decreased with the increase of the wall thickness.

scholarly journals Structural Performance of uPVC Confined Concrete Equivalent Cylinders Under Axial Compression Loads

Buildings ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 82 ◽  
Author(s):  
Abraham Mengesha Woldemariam ◽  
Walter O. Oyawa ◽  
Timothy Nyomboi
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Construction Materials ◽  
Strain Curve ◽  
Fire Risk ◽  
Resistance Mechanisms ◽  
Concrete Cover ◽  
Wire Mesh ◽  
Aspect Ratios ◽  
Innovative System

There is always a need for more durable, ductile, and robust materials for buildings, bridges, and other infrastructure due to the drawbacks of existing construction materials. Some of the drawbacks are the corrosion of steel, the brittle failure of concrete, and the performance instabilities that are caused when exposed to different environments. Thus, an innovative system is required to improve the performance and retain the integrity of structures in a harsh environment. To alleviate the situation, Un-plasticized polyvinyl chloride (uPVC) tubes are used as a confining material and their performance was experimentally evaluated by testing uPVC confined equivalent cylinders. Accordingly, unconfined and uPVC confined equivalent concrete cylinders for five different concrete classes, four types of uPVC tube sizes, and the aspect ratios of two (h/D = 2) were prepared and tested under axial compression loads. The result shows that the uPVC confinement increased the strength, ductility factor, and energy absorption in between 1.28–2.35, 1.84–15.3, and 11–243 times the unconfined levels, respectively. The confinement performed well for lower concrete classes and higher thickness to diameter ratios (2t/D). The post-peak behavior of the stress-strain curve was affected by the 2t/D ratio and the absolute value of the slope decreased as the 2t/D ratio increased. Additionally, the uPVC tube has shown several advantages, such as acting as a permanent formwork, protecting the concrete from chemical attacks, preventing the segregation of concrete, preventing peeling, and taking off concrete cover, decreasing the cross-section, and resulting in lighter sections. The uPVC confinement provided a remarkable improvement on the strength, ductility, energy absorption, and post-peak behavior of concrete. Therefore, uPVC tubes can be used as confining material for bridge piers, piles, electric poles, and highway signboards, where the fire risk is very small, though additional research is required on fire resistance mechanisms, such as wire-mesh reinforced mortar cover.

scholarly journals Thermoplastic composite beam structures from mixtures of recycled HDPE and rubber crumb for acoustic energy absorption

2016 ◽  
Vol 31 (1) ◽  
pp. 119-142 ◽  
Author(s):  
B Haworth ◽  
D Chadwick ◽  
L Chen ◽  
YJ Ang
Keyword(s):  
Large Scale ◽  
Ad Hoc ◽  
Flexural Modulus ◽  
Acoustic Energy ◽  
Thermoplastic Composite ◽  
Rubber Crumb ◽  
Frequency Range ◽  
Compression Moulding ◽  
Graded Structures ◽  
Recycled Hdpe

The use of recycled rubber crumb in the design and production of thermoplastic-rubber composites as sound absorbers can provide solutions to noise pollution and for the recovery of post-consumer materials from both packaging and waste tyres. The work of this study is concerned with the effect of rubber crumb incorporation in high-density polyethylene (HDPE) and also in HDPE glass fibre composites on acoustic, mechanical and physical properties. Recycled HDPE compounds containing variable concentrations of cured rubber crumb particles were prepared by twin screw extrusion. Thermal analysis has revealed a significant increase in the level of crystallinity of the HDPE component by increasing the rubber content in the mixes. Standard three-point bending and notched impact test specimens were manufactured by injection moulding, and large-scale beam samples were produced by compression moulding using an ad hoc method that allows variation of the through-thickness elastomer content as a means of obtaining composition gradients. The flexural modulus and impact strength varied monotonically with rubber crumb concentration. A fast Fourier transform technique was used to determine the acoustic performance of the beams over a wide frequency range. The graded structures produced large improvements in acoustic absorption properties in the frequency range of 2–6 kHz, notably from composite beams containing 20% rubber and also in some multilayer beams with rubber concentration gradients.

scholarly journals Progressive Crushing Behavior and Energy Absorption of Unidirectional CFRP Plate under Axial Compression

2010 ◽  
Vol 36 (3) ◽  
pp. 104-111 ◽  
Author(s):  
Masahito UEDA ◽  
Toyoshi TAKASHIMA ◽  
Yasuyuki KATO ◽  
Tetsu NISHIMURA
Keyword(s):  
Energy Absorption ◽  
Axial Compression ◽  
Cfrp Plate ◽  
Crushing Behavior
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