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1

Circumferential Compliance of Small Diameter Polyurethane Vascular Grafts Reinforced with Elastic Tubular Fabric

Yang H., Xu W., Ouyang C., Zhou F., Cui W., Yi C.

Fibres & Textiles in Eastern Europe

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2009

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Vol. 17, no. 6 (77)

89--92

EN

Small diameter vascular grafts were fabricated from pure Polyurethane (PU), as well as PU reinforced with a weft-knitted tubular fabric. Textured polyester and Spandex blend yarns were used for knitting on a purpose-built weft-knitting machine. The circumferential compliance properties of the reinforced composite vascular grafts were compared with those of the tubular fabric itself and the pure PU vascular grafts. The elasticity and strength of the reinforced vascular grafts were improved in the radius compared with the tubular fabric. The strength of the reinforced vascular grafts was 5 10 times that of the pure PU vascular grafts. Expanding the tubular fabric to increase the inner diameter of the reinforced vascular graft increased the graft’s strength and initial modulus, but the difference was reduced as the PU content was increased. For grafts of the same inner diameter, increasing the PU content increased the thickness and strength of the graft wall, which led to a general increase in the strength and initial modulus of the composite vascular grafts. The new composite vascular grafts combine the good elasticity and blood-proof properties of PU with the strength and stability of weft-knitted fabrics.

PL

Poliuretanowe protezy naczyniowe o małej średnicy zostały wyprodukowane z czystego poliuretanu jak również z poliuretanu wzmocnionego rządkowymi dzianinami rurkowymi. Dla wyprodukowania dzianin stosowano mieszaninę teksturowanych przędz poliestrowych i przędzy Spandex, które przerabiano na specjalnie wykonanej rządkowej maszynie dziewiarskiej. Właściwości obwodowe protez naczyniowych z rurkowymi dzianinami rządkowymi były porównywane z właściwościami czystych protez poliuretanowych. Okazało się, że właściwości elastyczne i wytrzymałościowe wzmocnionych protez były lepsze od protez konwencjonalnych. Wytrzymałość była większa pięciokrotnie od protez nie wzmocnionych. Zwiększenie średnicy dzianiny rurkowej powoduje wzrost wytrzymałości protezy i jej modułu początkowego ale różnica się zmniejsza przy wzroście udziału poliuretanu. Nowe wzmocnione kompozytowe protezy naczyniowe łączą w sobie dobrą elastyczność i kompatybilność poliuretanu z krwią oraz wytrzymałością i stabilnością rządkowych dzianin rurkowych.

2

Vibrational power flow in beam-plate structures: Part II: Beam plate-structure with isolating components

Yi C., Dietz P., Hu X.

Computer Assisted Mechanics and Engineering Sciences

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1998

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Vol. 5, nr 4

361-372

EN

The expressions of vibrational power flow (VPF) in beam-plate stuctures (BPS) have been derived in the Part I of this paper. Based on those results got in Part I, Part II presents the expressions of VPF in BPS under the following three cases as shown Figs. 1,2 and 3 below. (1) the isolating component 1 (IC1) being added at the free end of the beam; (2) isolating component 2 (IC2) being embedded between the beam and the plate; and (3) IC1 and IC2 being in BPS simultaneously (IC1 and IC2). According to these expressions, the corresponding numerical calculations are completed. The influence of parameter of the isolating components on VPF is also considered in this part. And then numerical calcilations of VPF are verified by the measurements of VPF. Some valuable conclusions have been applied to vibration control of tracked vehicles mentioned in Part I.

3

Vibrational power flow in beam-plate structures: Part I: Basic theory

Yi C., Dietz P., Hu X.

Computer Assisted Mechanics and Engineering Sciences

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1998

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Vol. 5, nr 4

345-359

EN

This paper presents the expressions of Vibrational Power Flow (VPF) in Beam-Plate Structures (BPS). These expressions are derived based on structural dynamics. BPS is composed of a constant cross-section beam and a thin flat rectangular plate. In expressions the plate is four-edge simply suppored and four-edge fixedly supported, respectively. The numerical calculation of these expressions is implemented. Meanwhile, the different parameters of beam and plate are also considered in the calculation. Finally, the numerical solutions of VPF in BPS are compared with the corresponding the measured VPF. The numerical VPFs have a good agreement with the measured VPF. The results of VPF provide a tool for analysing vibrational energy transmission between the support roller and the armored plate of tracked vehicles.