On design of novel bionic bamboo tubes for multiple compression load cases

2022 ◽  
pp. 107067
Author(s):  
Hongyu Liang ◽  
Wenqian Hao ◽  
Hao Sun ◽  
Yongfeng Pu ◽  
Ying Zhao ◽  
...  
Keyword(s):  
Compression Load ◽  
Multiple Compression

scholarly journals Hygrothermal Ageing Influence on BVI-Damaged Carbon/Epoxy Coupons under Compression Load

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2038
Author(s):  
Maria Pia Falaschetti ◽  
Matteo Scafé ◽  
Nicola Zavatta ◽  
Enrico Troiani
Keyword(s):  
Residual Strength ◽  
Impact Damage ◽  
Mechanical Analysis ◽  
Test Method ◽  
Combined Loading ◽  
Compression Load ◽  
Impact Location ◽  
Hygrothermal Ageing ◽  
Influence Of Water ◽  
Compressive Tests

Composite materials usage in several industrial fields is now widespread, and this leads to the necessity of overcoming issues that are still currently open. In the aeronautic industry, this is especially true for Barely Visible Impact Damage (BVID) and humidity uptake issues. BVID is the most insidious kind of impact damage, being rather common and not easily detectable. These, along with the ageing that a composite structure could face during its operative life, could be a cause of fatal failures. In this paper, the influence of water absorption on impacted specimens compressive residual strength was studied. Specimens were impacted using a modified Charpy pendulum. Two different locations were chosen for comparison: Near-Edge (NE) and Central (CI). Accelerated hygrothermal ageing was conducted on impacted and reference nonimpacted coupons, placing them in a water-filled jar at 70 °C. Compressive tests were performed in accordance with the Combined Loading Compression (CLC) test method. A Dynamic Mechanical Analysis (DMA) was performed as well. The results showed the influence of hygrothermal ageing, as expected. Nevertheless, the influence of impact location on compressive residual strength is not clearly noticeable in aged specimens, leading to the conclusion that hygrothermal ageing may have a greater effect on composite compressive strength than the analysed BVI damage.

scholarly journals Accelerating In-Transit Co-Processing for Scientific Simulations Using Region-Based Data-Driven Analysis

Algorithms ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 154
Author(s):  
Marcus Walldén ◽  
Masao Okita ◽  
Fumihiko Ino ◽  
Dimitris Drikakis ◽  
Ioannis Kokkinakis
Keyword(s):  
Large Scale ◽  
Data Driven ◽  
Data Sets ◽  
Output Constraints ◽  
Data Driven Approach ◽  
Scientific Simulations ◽  
Multiple Metrics ◽  
In Transit ◽  
Multiple Compression ◽  
Large Scale Simulations

Increasing processing capabilities and input/output constraints of supercomputers have increased the use of co-processing approaches, i.e., visualizing and analyzing data sets of simulations on the fly. We present a method that evaluates the importance of different regions of simulation data and a data-driven approach that uses the proposed method to accelerate in-transit co-processing of large-scale simulations. We use the importance metrics to simultaneously employ multiple compression methods on different data regions to accelerate the in-transit co-processing. Our approach strives to adaptively compress data on the fly and uses load balancing to counteract memory imbalances. We demonstrate the method’s efficiency through a fluid mechanics application, a Richtmyer–Meshkov instability simulation, showing how to accelerate the in-transit co-processing of simulations. The results show that the proposed method expeditiously can identify regions of interest, even when using multiple metrics. Our approach achieved a speedup of 1.29× in a lossless scenario. The data decompression time was sped up by 2× compared to using a single compression method uniformly.

scholarly journals Load Distribution on PET-G 3D Prints of Honeycomb Cellular Structures under Compression Load

Polymers ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 1983
Author(s):  
Olimpia Basurto-Vázquez ◽  
Elvia P. Sánchez-Rodríguez ◽  
Graham J. McShane ◽  
Dora I. Medina
Keyword(s):  
Fused Deposition Modeling ◽  
Structural Characteristics ◽  
Honeycomb Structure ◽  
Cellular Structures ◽  
Displacement Curve ◽  
Compression Tests ◽  
Compression Load ◽  
Fused Deposition ◽  
3D Printed ◽  
Printing Direction

Energy resulting from an impact is manifested through unwanted damage to objects or persons. New materials made of cellular structures have enhanced energy absorption (EA) capabilities. The hexagonal honeycomb is widely known for its space-filling capacity, structural stability, and high EA potential. Additive manufacturing (AM) technologies have been effectively useful in a vast range of applications. The evolution of these technologies has been studied continuously, with a focus on improving the mechanical and structural characteristics of three-dimensional (3D)-printed models to create complex quality parts that satisfy design and mechanical requirements. In this study, 3D honeycomb structures of novel material polyethylene terephthalate glycol (PET-G) were fabricated by the fused deposition modeling (FDM) method with different infill density values (30%, 70%, and 100%) and printing orientations (edge, flat, and upright). The effectiveness for EA of the design and the effect of the process parameters of infill density and layer printing orientation were investigated by performing in-plane compression tests, and the set of parameters that produced superior results for better EA was determined by analyzing the area under the curve and the welding between the filament layers in the printed object via FDM. The results showed that the printing parameters implemented in this study considerably affected the mechanical properties of the 3D-printed PET-G honeycomb structure. The structure with the upright printing direction and 100% infill density exhibited an extension to delamination and fragmentation, thus, a desirable performance with a long plateau region in the load–displacement curve and major absorption of energy.

scholarly journals Influence of Rhamnolipids and Ionic Cross-Linking Conditions on the Mechanical Properties of Alginate Hydrogels as a Model Bacterial Biofilm

2021 ◽  
Vol 22 (13) ◽  
pp. 6840
Author(s):  
Natalia Czaplicka ◽  
Szymon Mania ◽  
Donata Konopacka-Łyskawa
Keyword(s):  
Mechanical Properties ◽  
Pure Water ◽  
Testing Machine ◽  
Bacterial Biofilm ◽  
Ion Trapping ◽  
Cross Linking ◽  
Box Behnken Design ◽  
Compression Load ◽  
Alginate Hydrogels ◽  
Biofilm Structure

The literature indicates the existence of a relationship between rhamnolipids and bacterial biofilm, as well as the ability of selected bacteria to produce rhamnolipids and alginate. However, the influence of biosurfactant molecules on the mechanical properties of biofilms are still not fully understood. The aim of this research is to determine the effect of rhamnolipids concentration, CaCl2 concentration, and ionic cross-linking time on the mechanical properties of alginate hydrogels using a Box–Behnken design. The mechanical properties of cross-linked alginate hydrogels were characterized using a universal testing machine. It was assumed that the addition of rhamnolipids mainly affects the compression load, and the value of this parameter is lower for hydrogels produced with biosurfactant concentration below CMC than for hydrogels obtained in pure water. In contrast, the addition of rhamnolipids in an amount exceeding CMC causes an increase in compression load. In bacterial biofilms, the presence of rhamnolipid molecules does not exceed the CMC value, which may confirm the influence of this biosurfactant on the formation of the biofilm structure. Moreover, rhamnolipids interact with the hydrophobic part of the alginate copolymer chains, and then the hydrophilic groups of adsorbed biosurfactant molecules create additional calcium ion trapping sites.

scholarly journals The Dose-Response Relationship Between Cumulative Lifting Load and Lumbar Disk Degeneration Based on Magnetic Resonance Imaging Findings

2014 ◽  
Vol 94 (11) ◽  
pp. 1582-1593 ◽  
Author(s):  
Yu-Ju Hung ◽  
Tiffany T-F. Shih ◽  
Bang-Bin Chen ◽  
Yaw-Huei Hwang ◽  
Li-Ping Ma ◽  
...  
Keyword(s):  
Magnetic Resonance Imaging ◽  
Magnetic Resonance ◽  
Dose Response ◽  
Response Relationship ◽  
Resonance Imaging ◽  
Dose Response Relationship ◽  
Compression Load ◽  
Lumbar Disk ◽  
Lumbar Disk Degeneration ◽  
Disk Height

BackgroundLumbar disk degeneration (LDD) has been related to heavy physical loading. However, the quantification of the exposure has been controversial, and the dose-response relationship with the LDD has not been established.ObjectiveThe purpose of this study was to investigate the dose-response relationship between lifetime cumulative lifting load and LDD.DesignThis was a cross-sectional study.MethodsEvery participant received assessments with a questionnaire, magnetic resonance imaging (MRI) of the lumbar spine, and estimation of lumbar disk compression load. The MRI assessments included assessment of disk dehydration, annulus tear, disk height narrowing, bulging, protrusion, extrusion, sequestration, degenerative and spondylolytic spondylolisthesis, foramina narrowing, and nerve root compression on each lumbar disk level. The compression load was predicted using a biomechanical software system.ResultsA total of 553 participants were recruited in this study and categorized into tertiles by cumulative lifting load (ie, <4.0 × 105, 4.0 × 105 to 8.9 × 106, and ≥8.9 × 106 Nh). The risk of LDD increased with cumulative lifting load. The best dose-response relationships were found at the L5–S1 disk level, in which high cumulative lifting load was associated with elevated odds ratios of 2.5 (95% confidence interval [95% CI]=1.5, 4.1) for dehydration and 4.1 (95% CI=1.9, 10.1) for disk height narrowing compared with low lifting load. Participants exposed to intermediate lifting load had an increased odds ratio of 2.1 (95% CI=1.3, 3.3) for bulging compared with low lifting load. The tests for trend were significant.LimitationsThere is no “gold standard” assessment tool for measuring the lumbar compression load.ConclusionsThe results suggest a dose-response relationship between cumulative lifting load and LDD.

Degradation of critical current in Bi2212 composite wire under compression load

2017 ◽  
Vol 38 (12) ◽  
pp. 1773-1784 ◽  
Author(s):  
Zhiyang Wang ◽  
Huadong Yong ◽  
Youhe Zhou
Keyword(s):  
Critical Current ◽  
Composite Wire ◽  
Compression Load

Analysis and Comparison of Seal Ability of Premium Tubing Connections under Axial Alternating Load

2013 ◽  
Vol 423-426 ◽  
pp. 2035-2039
Author(s):  
Long Cang Huang ◽  
Yin Ping Cao ◽  
Yang Yu ◽  
Yi Hua Dou
Keyword(s):  
Contact Pressure ◽  
Oil And Gas ◽  
Element Analysis ◽  
Gas Well ◽  
Cycle Number ◽  
Compression Load ◽  
Well Production ◽  
Maximum Contact ◽  
Contact Pressures ◽  
Better Than

In the process of oil and gas well production, tubing connection stand the axial alternating load during open well, shut well and fluid flow. In order to know premium connection seal ability under the loading, two types of P110 88.9mmx6.45mm premium tubing connections which called A connection and B connection are performed with finite element analysis, in which contact pressures and their the regularities distribution on sealing surface are analyzed. The results show that with the increasing of cycle number, the maximum contact pressures on sealing surface of both A connection and B connection are decreased. The decreasing of the maximum contact pressures on B connection is greater than those on A connection. With the increasing of cycle number of axial alternating compression load, the maximum contact pressure on sealing surface of A connection is decreased, and the maximum contact pressure on sealing surface of B connection remains constant. Compared the result, it shows that the seal ability of A connection is better than B connection under axial alternating tension load, while the seal ability of B connection is better than type A connection under axial alternating compression load.

Driven cast-in-situ pile capacity: insights from dynamic and static load testing

2021 ◽  
Author(s):  
Kevin N. Flynn ◽  
Bryan A. McCabe
Keyword(s):  
Dynamic Load ◽  
Shear Stresses ◽  
Load Testing ◽  
Pile Capacity ◽  
Compression Load ◽  
Shaft Resistance ◽  
Pile Installation ◽  
Cast Concrete ◽  
Load Tests

Driven cast-in-situ (DCIS) piles are classified as large displacement piles. However, the use of an oversized driving shoe introduces additional complexities influencing shaft resistance mobilisation, over and above those applicable to preformed displacement piles. Therefore, several design codes restrict the magnitude of shaft resistance in DCIS pile design. In this paper, a series of dynamic load tests was performed on the temporary steel driving tubes during DCIS pile installation at three UK sites. The instrumented piles were subsequently subjected to maintained compression load tests to failure. The mobilised shear stresses inferred from the dynamic tests during driving were two to five times smaller than those on the as-constructed piles during maintained load testing. This was attributed to soil loosening along the tube shaft arising from the oversized base shoe. Nevertheless, the radial stress reductions appear to be reversible by the freshly-cast concrete fluid pressures which provide lower-bound estimates of radial total stress inferred from the measured shear stresses during static loading. This recovery in shaft resistance is not recognised in some European design practices, resulting in conservative design lengths. Whilst the shaft resistance of DCIS piles was underpredicted by the dynamic load tests, reasonable estimates of base resistance were obtained.

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