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Mechanical study of PLA-PCL fibers during in vitro degradation

Thermo-Mechanical Behaviour of Ultrahigh Molecular Weight Polyethylene-Carbon N...

Defect and Diffusion Forum Vols. 312-315 (2011) pp 331-340

Nonlinear viscoelastic analysis of thick-walled cylindrical composite pipes

This paper analyzes the effect of the polymer matrix non-viscoelastic behaviour in the mechanical behaviour of thick multilayered cylinders. The original contribution of this work is to provide novel approximate analytical solutions to compute the time-dependent internal stress state through the pipe thickness within the framework of nonlinear viscoelasticity theory. The structures considered are thick, multila...

Degradation and Viscoelastic Properties of PLA-PCL, PGA-PCL, PDO and PGA Fibres

Aliphatic polyesters, such as polylactic acid (PLA), polyglycolic acid (PGA), polycaprolactone (PCL), polydioxone (PDO) and others, have been commonly used in biodegradable products. Hydrolytic and/or enzymatic chain cleavage of these materials leads to α-hydroxyacids, which, in most cases, are ultimately assimilated in human body or in a composting environment. However, each of these has some shortcomings...

On the prediction of long-term creep-failure of GRP pipes in aqueous environment

The aim of this work was to study the long-term failure of GAP (Glass fiber-reinforced Polymer) pipes under the influence of moisture absorption. These pipes are used in water transportation, which has an important effect on the mechanical properties of the polymeric matrix. The GRP pipes are usually tested under ring deflection or internal pressure conditions. This study presents and analyzes experimental cree...

Long-term behaviour of GFRP pipes: Reducing the prediction test duration

The certification of glass-fibre reinforced plastic (GFRP) piping systems is regulated by normative standards in which test series of 10,000 h are required to estimate the residual properties at the end of the expected life (normally, 50 years). In this paper, the possibility to reduce the test duration, whilst maintaining an equivalent prediction of long-term properties, is discussed. Experimental results from...

Development of ligament tissue biodegradable devices: A review

This bibliographic review is focused on ligament tissue rehabilitation, its anatomy-physiology, and, mainly, on the dimensioning considerations of a composite material solution. The suture strength is problematic during the tissue recovering, implying reduction of mobility for several months. However, early postoperative active mobilization may enable a faster and more effective recovering of tissue biomechanic...

Biomechanics of biomaterials used in soft tissue regenerative medicine

Biodegradable polymers have been used in implantable medical devices, such as suture fibers, fixation screws and soft tissue engineering devices. Apart from biological compatibility, these devices shall also be functional compatible and perform adequate mechanical temporary support during the healing process. In regenerative medicine, the scaffold that will provide this temporary support should simultaneously e...

Viscoplastic analysis of fiber reinforced polymer matrix composites under vario...

The present study aims modeling the viscoplastic behavior of polymer matrix composite laminates under different loading conditions. The adopted model is based on the one-parameter plasticity model employed to predict the plastic part of the recognized nonlinear behavior of fiber composites [C.T. Sun and J.L. Chen, J. Compos. Mater., 23, 1009 (1989)]. This model evolved to a three-parameter constitutive viscopla...

Stress strain analysis of a cylindrical pipe subjected to a transverse load and...

The increased use of polymers and reinforced polymers in civil construction applications originated elegant structures with a high specific strength and stiffness. The mechanical performance improved significantly in comparison with traditional materials; however, the structural engineers face new challenges. The high strength compared with the stiffness of these new materials allows large deformations without ...