Static compression experiments on low-Z planetary materials

The method to define strain characteristics of soil under dynamic loading is proposed based on the results of experiments on dynamic compression of soils on the device for dynamic loading in laboratory conditions; the method allows solving wave problems with the statement similar to the statement of experiments. Using the proposed method, the modulus of dynamic and static compression, the modulus of unloading, the coefficient of viscosity of loess soil in the range of seismic loads are determined in accordance with elastic-visco-plastic model of soil developed by G.M.Lyakhov.

Download Full-text

Quasi-Static Compression Stress-Strain Curves -- III. 5083-H131 Aluminum

10.21236/adb004159 ◽

1975 ◽

Author(s):

Ralph F. Benck ◽

Jr Murray ◽

E. A.

Keyword(s):

Compression Stress ◽

Stress Strain ◽

Static Compression ◽

Quasi Static Compression

Download Full-text

Out-of-plane static compression and energy absorption of paper hierarchical corrugation sandwich panels

The Journal of Strain Analysis for Engineering Design ◽

10.1177/03093247211008566 ◽

2021 ◽

pp. 030932472110085

Author(s):

Huineng Wang ◽

Yanfeng Guo ◽

Yungang Fu ◽

Dan Li

Keyword(s):

Yield Strength ◽

Bearing Capacity ◽

Energy Absorption ◽

Sandwich Panel ◽

Second Order ◽

Compression Rate ◽

Static Compression ◽

First Order ◽

Out Of Plane ◽

Analytical Approaches

This study introduces the opinion of the corrugation hierarchy to develop the second-order corrugation paperboard, and explore the deformation characteristics, yield strength, and energy absorbing capacity under out-of-plane static evenly compression loading by experimental and analytical approaches. On the basis of the inclined-straight strut elements of corrugation unit and plastic hinge lines, the yield and crushing strengths of corrugation unit were analyzed. This study shows that as the compressive stress increases, the second-order corrugation core layer is firstly crushed, and the first-order corrugation structures gradually compacted until the failure of entire structure. The corrugation type has an obvious influence on the yield strength of the corrugation sandwich panel, and the yield strength of B-flute corrugation sandwich panel is wholly higher than that of the C-flute structure. At the same compression rate, the flute type has a significant impact on energy absorption, and the C-flute second-order corrugation sandwich panel has better bearing capacity than the B-flute structure. The second-order corrugation sandwich panel has a better bearing capacity than the first-order structure. The static compression rate has little effect on the yield strength and deformation mode. However, with the increase of the static compression rate, the corrugation sandwich panel has a better cushioning energy absorption and material utilization rate.

Download Full-text

A Quasi-Static Quantitative Ultrasound Elastography Algorithm Using Optical Flow

Sensors ◽

10.3390/s21093010 ◽

2021 ◽

Vol 21 (9) ◽

pp. 3010

Author(s):

Raphael Lamprecht ◽

Florian Scheible ◽

Marion Semmler ◽

Alexander Sutor

Keyword(s):

Optical Flow ◽

Young’S Modulus ◽

Elastic Properties ◽

Young's Modulus ◽

Image Data ◽

Maximum Error ◽

Ultrasound Elastography ◽

Static Compression ◽

Tissue Properties ◽

A Performance

Ultrasound elastography is a constantly developing imaging technique which is capable of displaying the elastic properties of tissue. The measured characteristics could help to refine physiological tissue models, but also indicate pathological changes. Therefore, elastography data give valuable insights into tissue properties. This paper presents an algorithm that measures the spatially resolved Young’s modulus of inhomogeneous gelatin phantoms using a CINE sequence of a quasi-static compression and a load cell measuring the compressing force. An optical flow algorithm evaluates the resulting images, the stresses and strains are computed, and, conclusively, the Young’s modulus and the Poisson’s ratio are calculated. The whole algorithm and its results are evaluated by a performance descriptor, which determines the subsequent calculation and gives the user a trustability index of the modulus estimation. The algorithm shows a good match between the mechanically measured modulus and the elastography result—more precisely, the relative error of the Young’s modulus estimation with a maximum error 35%. Therefore, this study presents a new algorithm that is capable of measuring the elastic properties of gelatin specimens in a quantitative way using only the image data. Further, the computation is monitored and evaluated by a performance descriptor, which measures the trustability of the results.

Download Full-text

Experimental and numerical studies on failure and energy absorption of composite thin-walled square tubes under quasi-static compression loading

International Journal of Nonlinear Sciences and Numerical Simulation ◽

10.1515/ijnsns-2019-0062 ◽

2020 ◽

Vol 21 (6) ◽

pp. 623-634

Author(s):

Haolei Mou ◽

Zhenyu Feng ◽

Jiang Xie ◽

Jun Zou ◽

Kun Zhou

Keyword(s):

Finite Element ◽

Shell Model ◽

Energy Absorption ◽

Failure Mode ◽

Failure Criterion ◽

Finite Element Models ◽

Static Compression ◽

Compression Loading ◽

Thin Walled ◽

Simulation Results

AbstractTo analysis the failure and energy absorption of carbon fiber reinforced polymer (CFRP) thin-walled square tube, the quasi-static axial compression loading tests are conducted for [±45]3s square tube, and the square tube after test is scanned to further investigate the failure mechanism. Three different finite element models, i.e. single-layer shell model, multi-layer shell model and stacked shell mode, are developed by using the Puck 2000 matrix failure criterion and Yamada Sun fiber failure criterion, and three models are verified and compared according to the experimental energy absorption metrics. The experimental and simulation results show that the failure mode of [±45]3s square tube is the local buckling failure mode, and the energy are absorbed mainly by intralaminar and interlaminar delamination, fiber elastic deformation, fiber debonding and fracture, matrix deformation cracking and longitudinal crack propagation. Three different finite element models can reproduce the collapse behaviours of [±45]3s square tube to some extent, but the stacked shell model can better reproduce the failure mode, and the difference of specific energy absorption (SEA) is minimum, which shows the numerical simulation results are in better agreement with the test results.

Download Full-text

Study on improvement of prefolded energy absorption device to constant resistance and its mechanical properties

Science Progress ◽

10.1177/00368504211036820 ◽

2021 ◽

Vol 104 (3) ◽

pp. 003685042110368

Author(s):

Dong An ◽

Jiaqi Song ◽

Hailiang Xu ◽

Jingzong Zhang ◽

Yimin Song ◽

...

Keyword(s):

Mechanical Properties ◽

Energy Absorption ◽

Compression Test ◽

Side Wall ◽

Concave Side ◽

Displacement Curve ◽

Static Compression ◽

Constant Resistance ◽

The Impact ◽

Force Displacement

When the rock burst occurs, energy absorption support is an important method to solve the impact failure. To achieve constant resistance performance of energy absorption device, as an important component of the support, the mechanical properties of one kind of prefolded tube is analyzed by quasi-static compression test. The deformation process of compression test is simulated by ABAQUS and plastic strain nephogram of the numerical model are studied. It is found that the main factors affecting the fluctuation of force-displacement curve is the stiffness of concave side wall. The original tube is improved to constant resistance by changing the side wall. The friction coefficient affects the folding order and form of the energy absorbing device. Lifting the concave side wall stiffness can improve the overall stiffness of energy absorption device and slow down the falling section of force-displacement curve. It is always squeezed by adjacent convex side wall in the process of folding, with large plastic deformation. Compared with the original one, the improved prefolded tube designed in this paper can keep the maximum bearing capacity ( Pmax), increase the total energy absorption ( E), improve the specific energy absorption (SEA), and decrease the variance ( S2) of force-displacement curve.

Download Full-text

Behavior of rubidium at over eightfold static compression

Physical Review B ◽

10.1103/physrevb.103.224103 ◽

2021 ◽

Vol 103 (22) ◽

Author(s):

C. V. Storm ◽

J. D. McHardy ◽

S. E. Finnegan ◽

E. J. Pace ◽

M. G. Stevenson ◽

...

Keyword(s):

Static Compression

Download Full-text

Involvement of Autophagy in Rat Tail Static Compression-Induced Intervertebral Disc Degeneration and Notochordal Cell Disappearance

International Journal of Molecular Sciences ◽

10.3390/ijms22115648 ◽

2021 ◽

Vol 22 (11) ◽

pp. 5648

Author(s):

Takashi Yurube ◽

Hiroaki Hirata ◽

Masaaki Ito ◽

Yoshiki Terashima ◽

Yuji Kakiuchi ◽

...

Keyword(s):

Intervertebral Disc ◽

Disc Degeneration ◽

Time Course ◽

The Body ◽

Terminal Deoxynucleotidyl Transferase ◽

Autophagic Flux ◽

Static Compression ◽

Notochordal Cell ◽

Notochordal Cells ◽

Rat Tail

The intervertebral disc is the largest avascular low-nutrient organ in the body. Thus, resident cells may utilize autophagy, a stress-response survival mechanism, by self-digesting and recycling damaged components. Our objective was to elucidate the involvement of autophagy in rat experimental disc degeneration. In vitro, the comparison between human and rat disc nucleus pulposus (NP) and annulus fibrosus (AF) cells found increased autophagic flux under serum deprivation rather in humans than in rats and in NP cells than in AF cells of rats (n = 6). In vivo, time-course Western blotting showed more distinct basal autophagy in rat tail disc NP tissues than in AF tissues; however, both decreased under sustained static compression (n = 24). Then, immunohistochemistry displayed abundant autophagy-related protein expression in large vacuolated disc NP notochordal cells of sham rats. Under temporary static compression (n = 18), multi-color immunofluorescence further identified rapidly decreased brachyury-positive notochordal cells with robust expression of autophagic microtubule-associated protein 1 light chain 3 (LC3) and transiently increased brachyury-negative non-notochordal cells with weaker LC3 expression. Notably, terminal deoxynucleotidyl transferase dUTP nick end labeling-positive apoptotic death was predominant in brachyury-negative non-notochordal cells. Based on the observed notochordal cell autophagy impairment and non-notochordal cell apoptosis induction under unphysiological mechanical loading, further investigation is warranted to clarify possible autophagy-induced protection against notochordal cell disappearance, the earliest sign of disc degeneration, through limiting apoptosis.

Download Full-text

Analysis of the Strain and Stress Fields of Cardboard Box during Compression by 3D Digital Image Correlation

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.24-25.103 ◽

2010 ◽

Vol 24-25 ◽

pp. 103-108 ◽

Cited By ~ 3

Author(s):

Jeremie Viguié ◽

P.J.J. Dumont ◽

P. Vacher ◽

Laurent Orgéas ◽

I. Desloges ◽

...

Keyword(s):

Compression Strength ◽

Compressive Loading ◽

Image Correlation ◽

Parallel Plates ◽

Static Compression ◽

3D Digital Image Correlation ◽

Plastic Materials ◽

Semi Empirical ◽

And Storage ◽

Quasi Static Compression

Corrugated boards with small flutes appear as good alternatives to replace packaging folding boards or plastic materials due their small thickness, possibility of easy recycling and biodegradability. Boxes made up of these materials have to withstand significant compressive loading conditions during transport and storage. In order to evaluate their structural performance, the box compression test is the most currently performed experiment. It consists in compressing an empty container between two parallel plates at constant velocity. Usually it is observed that buckling phenomena are localized in the box panels, which bulge out during compression [1]. At the maximum recorded compression force, the deformation localises around the box corners where creases nucleate and propagate. This maximum force is defined as the quasi-static compression strength of the box. The prediction of such strength is the main topic of interest of past and current research works. For example, the box compression behaviour of boxes was studied by Mc Kee et al. [2] and Urbanik [3], who defined semi-empirical formula to predict the box compression strength, as well as by Beldie et al. [4] and Biancolini et al. [5] by finite element simulations. But comparisons of these models with experimental results remain rather scarce and limited.

Download Full-text