A Preliminary Study on the Mechanical Performance of Tiled Polymer Composites

2006 ◽  
Author(s):  
M. A. Qidwai ◽  
J. N. Baucom ◽  
A. C. Leung ◽  
J. P. Thomas
Keyword(s):  
Composite Laminates ◽  
Load Transfer ◽  
Mechanical Performance ◽  
Local Stress ◽  
Superior Performance ◽  
Design Parameters ◽  
Interlaminar Stresses ◽  
Stress Concentrations ◽  
Critical Design ◽  
Composite Joint

We are developing and exploring the concept of in-plane tiling of composite laminates, called MOSAIC, to mitigate or control delamination at free edges due to interlaminar stresses. Initial mechanical testing has shown that MOSAIC composites with uniaxial graphite-fiber reinforced tiles retain the stiffness levels of traditional uniaxially reinforced composites but with reduced strength. The reduction in strength is attributed to the formation of resin-rich pockets between adjacent tiles. In this study, we have performed detailed finite element analyses to identify the critical design parameters that affect the mechanical performance of uniaxially reinforced MOSAIC composites. We have found that using continuous laminae on the outer surfaces significantly increases the overall loadcarrying capacity. Increasing aspect ratio of the pocket and decreasing material property differences between resin and tiles also cause better load transfer between tiles but may not necessarily improve overall strength due to increasing stress concentration. The tiling scheme and density of pocket placement influence the interaction of local stress concentrations. Consequently, a novel composite joint is proposed and found to have superior performance.

Characteristic Fracture Assessment of a Rivet Joint for Hybrid Composite Laminates under Static and Fatigue Shear Loads

2006 ◽  
Vol 326-328 ◽  
pp. 1757-1760 ◽  
Author(s):  
Dal Woo Jung ◽  
Nak Sam Choi
Keyword(s):  
Hybrid Composite ◽  
Composite Laminates ◽  
Pure Shear ◽  
Local Stress ◽  
Cyclic Fatigue ◽  
Shear Loading ◽  
Design Parameters ◽  
Tensile Fracture ◽  
Shear Mode ◽  
Composite Joint

Fatigue fracture behavior of a hybrid composite joint with riveting was evaluated in comparison to the case of static fracture. Hybrid composite joint specimens for shear test were made with layers of carbon fiber/epoxy composite and stainless steel. Characteristic fracture behaviors of those specimens were obviously different under static and cyclic loads. Static shear loading showed the fracture of a pure shear mode, whereas cyclic fatigue-shear loading caused the local stress concentration of a tensile mode and thus brought about the tensile fracture at that site. Experimental results obtained by static and fatigue tests were considered in modifications of design parameters of the hybrid joint.

Interlaminar Stresses in Composite Laminates Subjected to Twisting Deformation

2017 ◽  
Vol 84 (10) ◽  
Author(s):  
Johnathan Goodsell ◽  
Bo Peng ◽  
R. Byron Pipes ◽  
Wenbin Yu
Keyword(s):  
Composite Laminates ◽  
Load Transfer ◽  
Interlaminar Stresses ◽  
Thermoelastic Deformation ◽  
Interlaminar Stress ◽  
Bending Deformation ◽  
Axial Extension ◽  
The Cross ◽  
Twisting Deformation

The interlaminar stress in angle-ply and cross-ply composite laminates subjected to twisting deformation are investigated. Two mechanisms of interlaminar load transfer have been developed by studying the angle-ply laminate and the cross-ply laminate subjected to uniform axial extension, thermoelastic deformation and anticlastic bending deformation. In the present, these mechanisms are investigated in laminates subjected to twisting deformation. It is shown that the mechanisms of interlaminar load transfer in twisting deformation are identical to those previously investigated, though they arise from different causes. Furthermore, a unified treatment of the mechanisms of interlaminar load transfer is presented for the angle-ply laminate and the cross-ply laminate subjected to the four aforementioned modes of deformation.

scholarly journals Towards Assessment of Reliable Mechanical Properties for Knitted Fabric-Reinforced Thermoplastic Composites

1998 ◽  
Vol 7 (2) ◽  
pp. 096369359800700 ◽  
Author(s):  
J. Karger-Kocsis
Keyword(s):  
Composite Laminates ◽  
Load Transfer ◽  
Mechanical Performance ◽  
Damage Zone ◽  
Stress Transfer ◽  
Thermoplastic Composites ◽  
Knitted Fabric ◽  
Damage Development ◽  
Characterization Methods ◽  
Measuring Techniques

Since the mechanical performance of knitted fabric-reinforced thermoplastic (KFRT) composites is closely matched to composite laminates composed of unidirectional (UD) plies, attempts are made to adopt the characterization methods of the latter also for KFRT. This approach is not straightforward, and even not viable in many cases due to a peculiar load transfer and damage development associated with the knit structure. Although produced in plane, the knitted layers in the composites are never planar anymore, but tend to adopt a higher than two-dimensional (2D) reinforcing sructure. That is the main reason why established testing techniques which work well for advanced composites fail for KFRT. In order to determine reliable mechanical parameters for KFRT, the size of the damage zone (where stress transfer occurs) should also be considered. This paper lists some suitable measuring techniques and related aspects based on the experience gained on multilayer, plain weft knit-reinforced composites with various thermoplastic matrices.

scholarly journals Mechanical Optimization of Concrete with Recycled PET Fibres Based on a Statistical-Experimental Study

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 240
Author(s):  
Alejandro Meza ◽  
Pablo Pujadas ◽  
Laura Montserrat Meza ◽  
Francesc Pardo-Bosch ◽  
Rubén D. López-Carreño
Keyword(s):  
Reinforced Concrete ◽  
Aspect Ratio ◽  
Mechanical Performance ◽  
Tensile Tests ◽  
Superior Performance ◽  
Fibre Reinforced Concrete ◽  
Marine Fauna ◽  
Recycled Pet ◽  
Pet Bottles ◽  
Fibre Aspect Ratio

Discarded polyethylene terephthalate (PET) bottles have damaged our ecosystem. Problems of marine fauna conservation and land fertility have been related to the disposal of these materials. Recycled fibre is an opportunity to reduce the levels of waste in the world and increase the mechanical performance of the concrete. PET as concrete reinforcement has demonstrated ductility and post-cracking strength. However, its performance could be optimized. This study considers a statistical-experimental analysis to evaluate recycled PET fibre reinforced concrete with various fibre dose and aspect ratio. 120 samples were experimented under workability, compressive, flexural, and splitting tensile tests. The results pointed out that the fibre dose has more influence on the responses than its fibre aspect ratio, with statistical relation on the tensional toughness, equivalent flexural strength ratio, volumetric weight, and the number of fibres. Moreover, the fibre aspect ratio has a statistical impact on the tensional toughness. In general, the data indicates that the optimal recycled PET fibre reinforced concrete generates a superior performance than control samples, with an improvement similar to those reinforced with virgin fibres.

Automated simulation techniques for uncovering high-performance bioinspired cellular structures under blast loads

2021 ◽  
pp. 109963622110204
Author(s):  
Abdallah Ghazlan ◽  
Tuan Ngo ◽  
Tay Son Le ◽  
Tu Van Le
Keyword(s):  
Energy Dissipation ◽  
Trabecular Bone ◽  
Reaction Force ◽  
Blast Loading ◽  
Performance Criteria ◽  
Superior Performance ◽  
Cellular Structures ◽  
Design Parameters ◽  
Engineering Practice ◽  
Automated Simulation

Trabecular bone possesses a complex hierarchical structure of plate- and strut-like elements, which is analogous to structural systems encountered in engineering practice. In this work, key structural features of trabecular bone are mimicked to uncover effective energy dissipation mechanisms under blast loading. To this end, several key design parameters were identified to develop a bone-like unit cell. A computer script was then developed to automatically generate bone-like finite element models with many combinations of these design parameters, which were simulated under blast loading. The optimal structure was identified and its performance was benchmarked against traditional engineered cellular structures, including those with hexagonal, re-entrant and square cellular geometries. The bone-like structure showed superior performance over its engineered counterparts using the peak transmitted reaction force and energy dissipation as the key performance criteria.

scholarly journals Evaluation of Interlaminar Stresses in Composite Laminates with a Bolt-Filled Hole Using a Linear Elastic Traction-Separation Description

2017 ◽  
Vol 7 (1) ◽  
pp. 93
Author(s):  
Yong Cao ◽  
Yunwen Feng ◽  
Xiaofeng Xue ◽  
Wenzhi Wang ◽  
Liang Bai
Keyword(s):  
Composite Laminates ◽  
Interlaminar Stresses ◽  
Linear Elastic

Lateral Load Performance of Panelized Wood I-Joist Floor Systems

2020 ◽  
Vol 70 (4) ◽  
pp. 428-438
Author(s):  
Sigong Zhang ◽  
Ying Hei Chui ◽  
David Joo
Keyword(s):  
Load Transfer ◽  
Mechanical Performance ◽  
Small Scale ◽  
Construction Time ◽  
Plane Shear ◽  
Floor Systems ◽  
Diaphragm Action ◽  
Wood Frame ◽  
Strength And Stiffness ◽  
Frame Construction

Abstract Panelized light wood frame construction is becoming more popular due to the faster construction time and shortage of onsite skilled labor. To use light wood frame panels effectively in panelized floor systems, panel-to-panel joints must be fastened adequately to allow load transfer between panels. They must also possess in-plane shear strength and stiffness comparable to stick-built, staggered-sheathed assemblies. This study was designed to develop efficient and effective panel-to-panel joints for connecting adjacent floor panels built with wood I-joists and evaluate the efficiency of the joints in achieving diaphragm action. At first, a number of these panel-to-panel joints were tested in the laboratory using a small-scale diaphragm test setup to determine their efficiency in transferring in-plane forces between panels. Test results showed that a small decrease in in-plane stiffness was expected for the most effective joints, but their strengths were significantly higher than at the same location in a conventional site-built floor diaphragm. The presence of blockings and use of two-row nailing were found to considerably improve stiffness and strength. These features can be used to mitigate the potential reduction in mechanical performance of panelized floor construction, in comparison with the site-built wood I-joist floor.

Damage Control in Composite Laminates

2001 ◽  
Author(s):  
Alexander P. Suvorov ◽  
George J. Dvorak
Keyword(s):  
Composite Laminates ◽  
Composite Laminate ◽  
Damage Control ◽  
Thermomechanical Loading ◽  
Interlaminar Stresses ◽  
Damage Resistance ◽  
Viscoelastic Composite ◽  
Mechanical Loads ◽  
Composite Damage ◽  
The Matrix

Abstract Several effects that fiber prestress may have on stress redistribution in the plies of composite laminates and in the phases of individual plies are illustrated. These include improvement of composite damage resistance under tensile mechanical loads, reduction/cancelation of interlaminar stresses at free edges of composite laminate subjected to thermomechanical loading, and stress relaxation in the matrix phase of viscoelastic composite laminates. Specific results are found for quasi-isotropic and cross-ply symmetric S-glass/epoxy and carbon/epoxy AS4/EPON 828 laminates.

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