Research and Analysis on Damage of Marine Ship Structures by Composite Materials Based on FEM Numerical Simulation

2020 ◽  
Vol 852 ◽  
pp. 129-138
Author(s):  
Hai Bo Xie ◽  
Zheng Jiang Liu ◽  
Yang Song ◽  
Shi Bo Zhou
Keyword(s):  
Numerical Simulation ◽  
Composite Structure ◽  
Failure Load ◽  
Simulation Method ◽  
Sandwich Composite ◽  
Initial Stiffness ◽  
Initial Failure ◽  
Ultimate Failure Load ◽  
Ultimate Failure ◽  
Sandwich Composite Structure

In view of the particularity of marine foam sandwich composite structure, this paper establishes an equivalent parameter conversion system based on the classical sandwich structure design idea, and forms an equivalent simulation method to determine the initial stiffness, initial failure load and ultimate failure load of the structure. The simulation discriminant method makes the SHELL91 shell unit available for the marine foam sandwich composite structure. The bending test of the basic structure of marine foam sandwich composite beams and plates is described in detail. The equivalent simulation method is verified. The initial stiffness, initial failure load and ultimate failure load of the equivalent simulation are in good agreement with the experimental results. The paper finds through the finite element numerical simulation that the research results are consistent with the reality and have strong practicability and popularization. The paper preliminarily believes that this method can be applied to the simulation calculation of large foam sandwich composite ships and marine structures. The calculation amount is greatly reduced based on ensuring the accuracy, and the calculation work such as strength criterion and stiffness check of the overall structure has Strongly convincing.

Study on Sandwich Core Modeling for Structural Analysis of Sandwich Composite Structure

2018 ◽  
Vol 926 ◽  
pp. 57-63
Author(s):  
Hyun Bum Park
Keyword(s):  
Structural Analysis ◽  
Composite Structure ◽  
Solid Modeling ◽  
Modeling Method ◽  
Core Structure ◽  
Sandwich Composite ◽  
Damage Area ◽  
The Core ◽  
Sandwich Core ◽  
Sandwich Composite Structure

This study aims to investigate numerically the damage area of a sandwich composite structure. In this work, the optimal sandwich core modeling method was proposed. This study applied two modeling methods to compare their analysis results for the structural analysis of the sandwich composite structure. Firstly, the modeling of sandwich core structure was performed with laminate modeling method. Secondly, the modeling of core structure was performed with core solid modeling method. The laminate modeling method was compared with the core solid modeling method. For the modeling, a carbon/epoxy composite structure was applied to the face sheet. And a nomex honeycomb core was applied to the core. Finally, comparing the result of modeling as actual shape with the one of virtually applying the thickness and modeling, it was examined that the former had three times more stress than the latter.

scholarly journals Different Suture Materials for Arthroscopic Transtibial Pull-out Repair of Medial Meniscal Posterior Root Tears: A Human Biomechanical Study

2019 ◽  
Vol 7 (9) ◽  
pp. 232596711987327
Author(s):  
Gilberto Y. Nakama ◽  
Zachary S. Aman ◽  
Hunter W. Storaci ◽  
Alexander S. Kuczmarski ◽  
Joseph J. Krob ◽  
...  
Keyword(s):  
Medial Meniscus ◽  
Failure Load ◽  
Clinical Care ◽  
Posterior Root ◽  
Clinical Failure ◽  
Postoperative Rehabilitation ◽  
Pull Out ◽  
Ultimate Failure Load ◽  
Ultimate Failure ◽  
Suture Tape

Background: Transtibial pull-out repair of the medial meniscal posterior root (MMPR) has been largely assessed through biomechanical studies. Biomechanically comparing different suture types would further optimize MMPR fixation and affect clinical care. Purpose/Hypothesis: The purpose of this study was to determine the optimal suture material for MMPR fixation. It was hypothesized that ultra high–molecular weight polyethylene (UHMWPE) suture tape would be biomechanically superior to UHMWPE suture and standard suture. Study Design: Controlled laboratory study. Methods: The MMPR attachment was divided in 24 human cadaveric knees and randomly assigned to 3 repair groups: UHMWPE suture tape, UHMWPE suture, and standard suture. Specimens were dissected down to the medial meniscus, and the posterior root attachments were sectioned off the tibia. Two-tunnel transtibial pull-out repair with 2 sutures, as determined by the testing group, was performed. The repair constructs were cyclically loaded between 10 and 30 N at 0.5 Hz for 1000 cycles to mimic the forces experienced on the medial meniscus during postoperative rehabilitation. Displacement was recorded at 1, 50, 100, 500, and 1000 cycles. Ultimate failure load, displacement at failure, and load at 3 mm of displacement (clinical failure) were also recorded. Results: UHMWPE suture tape had significantly less displacement of the medial meniscus when compared with standard suture at 1 (–0.22 mm [95% CI, –0.41 to –0.02]; P = .025) and 50 (–0.35 mm [95% CI, –0.67 to –0.03]; P = .029) cycles. There were no other significant differences observed in displacement between groups at any number of cycles. UHMWPE suture tape had significantly less displacement at the time of failure than standard suture (–3.71 mm [95% CI, –7.17 to –0.24]; P = .034). UHMWPE suture tape had a significantly higher load to reach the clinical failure displacement of 3 mm than UHMWPE suture (15.64 N [95% CI, 0.02 to 31.26]; P = .05). There were no significant differences in ultimate failure load between groups. Conclusion: The meniscal root repair construct with UHMWPE suture tape may be stronger and less prone to displacement than that with standard suture or UHMWPE suture. Clinical Relevance: UHMWPE suture tape may provide better clinical results compared with UHMWPE suture and standard suture.

scholarly journals Biomechanical evaluation of a novel double rip-stop technique with medial row knots for rotator cuff repair

2020 ◽  
Vol 9 (6) ◽  
pp. 285-292
Author(s):  
Zhanwen Wang ◽  
Hong Li ◽  
Zeling Long ◽  
Subin Lin ◽  
Andrew R. Thoreson ◽  
...  
Keyword(s):  
Rotator Cuff ◽  
Rotator Cuff Repair ◽  
Failure Modes ◽  
Failure Load ◽  
Biomechanical Properties ◽  
Gap Formation ◽  
Ultimate Failure Load ◽  
Fresh Frozen ◽  
Ultimate Failure ◽  
Cuff Repair

Aims Many biomechanical studies have shown that the weakest biomechanical point of a rotator cuff repair is the suture-tendon interface at the medial row. We developed a novel double rip-stop (DRS) technique to enhance the strength at the medial row for rotator cuff repair. The objective of this study was to evaluate the biomechanical properties of the DRS technique with the conventional suture-bridge (SB) technique and to evaluate the biomechanical performance of the DRS technique with medial row knots. Methods A total of 24 fresh-frozen porcine shoulders were used. The infraspinatus tendons were sharply dissected and randomly repaired by one of three techniques: SB repair (SB group), DRS repair (DRS group), and DRS with medial row knots repair (DRSK group). Specimens were tested to failure. In addition, 3 mm gap formation was measured and ultimate failure load, stiffness, and failure modes were recorded. Results The mean load to create a 3 mm gap formation in the DRSK and DRS groups was significantly higher than in the SB group. The DRSK group had the highest load to failure with a mean ultimate failure load of 395.0 N (SD 56.8) compared to the SB and DRS groups, which recorded 147.1 N (SD 34.3) and 285.9 N (SD 89.8), respectively (p < 0.001 for both). The DRS group showed a significantly higher mean failure load than the SB group (p = 0.006). Both the DRS and DRSK groups showed significantly higher mean stiffness than the SB group. Conclusion The biomechanical properties of the DRS technique were significantly improved compared to the SB technique. The DRS technique with medial row knots showed superior biomechanical performance than the DRS technique alone.

scholarly journals Steel-Concrete Sandwich Composite Structure

1992 ◽  
Vol 30 (5) ◽  
pp. 5-20 ◽  
Author(s):  
Tamon Ueda ◽  
Toshiyuki Shioya
Keyword(s):  
Composite Structure ◽  
Sandwich Composite ◽  
Sandwich Composite Structure

Prestressed concrete masonry walls subjected to uniform out-of-plane loading

1993 ◽  
Vol 20 (6) ◽  
pp. 969-979
Author(s):  
J. L. Dawe ◽  
G. G. Aridru
Keyword(s):  
Prestressed Concrete ◽  
Failure Load ◽  
Masonry Walls ◽  
Prestressing Force ◽  
Concrete Masonry ◽  
Ultimate Failure Load ◽  
Wall Stiffness ◽  
Out Of Plane ◽  
Ultimate Failure ◽  
Concrete Masonry Walls

Two series of post-tensioned concrete masonry walls subjected to uniform lateral loading were tested to investigate their flexural strength behaviour. Each series of walls consisted of four full-scale prestressed specimens, with varying levels of prestressing force, and one reinforced specimen. Of particular interest were the load–deflection curves, initial cracking loads, wall stiffness, crack patterns, and ultimate failure loads. An air bag test apparatus was used for applying lateral uniform pressures to the specimens. Results of this experimental investigation showed that, for a given wall thickness, increased prestressing force increases the cracking load, initial wall stiffness, and ultimate failure load. The results have established a linear relationship between increased prestressing force and initial cracking load, initial wall stiffness, and ultimate failure load. The proposed model, which takes into account changes in wall stiffness after initial cracking of the wall, accurately predicts wall behaviour. Key words: masonry, prestressed, walls, strength, behaviour, uniform, pressure, experimental, analytical.

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