No abstract

A numerical method of identification to derive the elastic properties of polymers from indentation experiments has been developed. Five different polymers were tested: amorphous and semi-crystalline polyethylene terephthalate (PET), semi-crystalline polyvinylidene fluoride (PVF 2 ), a copolymer of polyvinylidene fluoride and trifluorethylene, PCVF2/F3E) 60/40, and high pressure crystallised polyethylene (PE). The elastic properties of the polymers are calculated by two methods. On the basis of finite element solution, a simple function relating the load to the indentation depth and elastic modulus is first obtained. The elastic properties are then derived from the load-indentation depth and elastic modulus is first obtained. The elastic properties are then derived from the load indentation depth experimental data (loading curve). A second method to determine the elastic properties is based on using the experimental data of the unloading curve. Elastic properties obtained from loading and unloading curves are in good agreement.

Zusammenfassung Der Prozefl der Herstellung von Bau-T teilen aus Verbundwerkstoffen mit polymerer Matrix wird modelliert, wobei der Schwerpunkt beim Aush/irten des | auf die Form gelegten Halbzeugs liegt. Die Bauteile sollen A voraussetzungsgem/ifl die Form yon Rotationsschalen ha-~i, ben. Im Mittelpunkt steht die L6sung der nichtstation/iren W~irmeleitungsaufgabe ffir die Form und das Halbzeug Hi unter Ber/.icksichtigung der chemischen und Phasenum2i wandlungen in der polymeren Matrix. Mathematical modelling of the hardening process in thinwalled composite constructionsAbstract A present investigation suggest a mathematical Rl, R2 model for analyse a process of producing the composite construction elements with polymer matrix. The proposed w model is applicated here to thinwalled shells of revolution. The model allow to obtain a solution of the nonstationary thermoconduction problem for composite shells in conqp nection with hardening process in composite. Formelzeichen To rg rp T,