Dragos Alexandru Apostol

TL;DR: In this article, the authors presented the polyurethane foam fracture toughness results obtained for different foam densities and two types of specimens were used for determining fracture toughness in modes I, II and a mixed one, and the size effect, loading speed and loading direction were investigated.

TL;DR: In this article, a micromechanical model is proposed to estimate fracture toughness based on the tensile strength of the solid material and the topology of the cellular structure of polyurethane foams.

TL;DR: In this article, the behavior of closed cell rigid PUR foams under mixed mode loading was investigated using asymmetric semi-circular bend (ASCB) and asymmetric four-point bend (AFPB) specimens.

TL;DR: In this article, mixed mode fracture tests were performed using asymmetric semi-circular specimen and four fracture criteria (Maximum circumferen tial tensile stress, Minimum strain energy density, Maximum energy release rate, Equivalent stress intensity factor) were considered for evaluation of mixed-mode fracture of three closed cell rigid polyurethane foams with densities.

TL;DR: In this paper, the authors evaluated mixed-mode fracture of three closed-cell rigid polyurethane foams with densities: 100, 145 and 300 kg/m3.