Mechanical properties and impact behavior of a microcellular structural foam

Abstract

Structural foams are a relatively new class of materials with peculiar characteristics that make them very attractive in some energy absorption applications. They are currently used for packaging to protect goods from damage during transportation in the case of accidental impacts. Structural foams, in fact, have sufficient mechanical strength even with reduced weight: the balance between the two antagonist requirements demonstrates that these materials are profitable. Structural foams are generally made of microcellular materials, obtained by polymers where voids at the microscopic level are created. Although the processing technologies and some of the material properties, including mechanical, are well known, very little is established for what concerns dynamic impact properties, for the design of energy absorbing components made of microcellular foams. The paper reports a number of experimental results, in different loading conditions and loading speed, which will be a basis for the structural modeling.

Foams with Enhanced Ductility and Impact Behavior Based on Polypropylene Composites

“…A good explanation for the outstanding values of impact absorbed energy could be based on the outstanding values of elongation at break. Some studies have shown that a poor behavior at falling weight impact tests was due to the reduction in elongation at break [54]. In our case, the elongation was not reduced when foaming, in fact, it was increased and this increment in ductility could lead to an increment in the toughness of the foams.…”

Characterization of microcellular plastics for weight reduction in automotive interior parts

“…This is in concordance to the impact properties under falling dart tests of ABS foams reported by Avalle and Scattina [228], as well as other studies found in the literature with Polyetherimide (PEI) and their composites [181]. On the other hand, the reduction of the effective sectional area and cells collapse decrease the impact resistance.…”

Polymer foams as advanced energy absorbing materials for sports applications—A review

“…Higher relative densities usually result in better mechanical properties, as the structure is closer to the properties of the starting solid polymer. This was confirmed by Avalle and Scattina, 19 who summarized the results of previous tensile tests 20–22 on microcellular acrylonitrile–butadiene–styrene (ABS) foams and microcellular polycarbonate (PC) foams. Based on these results, the effect of relative density on relative Young's modulus can be described by a quadratic formula.…”

“…Based on these results, the effect of relative density on relative Young's modulus can be described by a quadratic formula. In this respect, relative Young's modulus is the quotient of the foam's Young modulus ( E h [Pa]) and the Young's modulus of the polymer matrix material ( E p [Pa]) 19 …”