Yield Strength Of Foams Research Articles

Structure and Compressive Properties of Silver Foams with Various Porosities

The sintering and dissolution process (SDP), in which NaCl is used as space holder, was used to produce open-cell Ag foams with various pore sizes. The content, size and shape of NaCl particles dictate the pore architecture of the foams. The yield strength of Ag foams decreases with increasing porosity. Of equivalent porosity, the yield strength of the foams with larger pore size is also higher than the foams with smaller pore size.

Simulation of Three-Point Bending Test of Titanium Foam for Biomedical Applications

Using Titanium (Ti) foam as an implant material is a new approach for biomedical applications and it is important to understand the mechanical behaviors of this new foam material. In the present study, the bending of the Ti foam has been simulated and compared against recently published data [1]. FE Analysis has been performed by Abaqus software. Stiffness and Yield strength of foams between 50% (cortical bone) to 80% (cancellous bone) porosity range were considered. This study showed that crushable foam material model in Abaqus, which has developed primarily for Aluminum (Al) foam alloys, is also valid for Ti Foam before any crack or damage occurs in the sample.

Mechanical properties of open‐pore titanium foam

Open-pore titanium foams are produced using the so-called space holder method. The mechanical properties of titanium foams with porosities of 50-80% are studied. The stiffness and yield strength of the foams are found to encompass the property range between cancellous bone and cortical bone. The analyzed foams are found to be anisotropic due to the use of nonspherical space holder particles which rearrange during the compaction of the powder mixture. The titanium foams are stronger perpendicular to the compaction direction and weaker along the compaction axis. In view of the application as an implant material in the lumbar spine, an intermediate porosity of 60-65% is analyzed more in detail. The typical yield strength of titanium foam with 62.5% porosity is above 60 MPa in compression, bending, and tension. Stiffness values vary with the testing method from 7-14 GPa.

Studies on the Dynamic Compressive Properties of Open-Celled Aluminum Alloy Foams

The compressive deformation behavior of open-cell aluminum foams with different densities and morphologies was assessed under quasi-static and dynamic loading conditions. High strain rate experiments were conducted using a split Hopkinson pressure bar technique at strain rates ranging from 500 to 1 2000 − s . The experimental results shown that the compressive stress-strain curves of aluminum foams also have the “ three regions” character appeared in general foam materials, namely elastic region, collapse region and densification regions. It is found that density is the primary variable characterizing the modulus and yield strength of foams and the cell appears to have a negligible effect on the strength of foams. It also is found that yield strength and energy absorption is almost insensitive to strain rate and deformation is spatially uniform for the open-celled aluminum foams, over a wide range of strain rates.

Studies on the dynamic compressive properties of open-cell aluminum alloy foams

Abstract The compressive deformation behavior of open-cell aluminum foams with different densities and morphologies is assessed under quasi-static and dynamic loading conditions. The experimental results show that density, in contrast with cell size, is the primary variable characterizing the elastic modulus and yield strength of foams. Yield strength and energy absorption of foams are almost insensitive to strain rate, over a wide range of strain rates.

In situ surface displacement analysis on sandwich and multilayer beams composed of aluminum foam core and metallic face sheets under bending loading

Abstract Deformation and damage mechanisms of sandwich and multilayer beams composed of aluminum foam core and metallic face sheets under four-point bending condition have been investigated in situ by surface displacement analysis software (SDA). Plastic collapse of the sandwich beams within the foam core is by two basic modes, indentation (ID) and core shear (CS), while failure of the multilayer beams depends on if their face sheets show ID or not. If a sandwich fails by ID, the multilayer beams with similar face sheets show ID mode in the first core and CS mode in the other cores of the beam. However, multilayer beams with face sheets that only display CS mode in sandwiches may fail in pure CS in every core. SDA results illustrated that indentation is locally compressive deformation on the beam beneath the loading rollers, where displacement and compressive strain are the maximum. In the case of CS that happens in the core between inner and outer rollers that corresponds to the maximum shear strain, discontinuously horizontal and vertical displacement is the mechanics factor for shear crack initiation, growth and broadening, and beam collapse. A simple criterion is given as F ID > F CS CS mode taking place, and F ID F CS ID mode taking place, for prediction of the failure mode, where FID and FCS are the loading limits of the indentation and core shear, which can be expressed as 4t(σcy × σfy)1/2 and 2(c + d)τcy, respectively (σcy: yield strength of foam, σfy: yield strength of face sheet, τcy: shear yield strength of foam, c: thickness of core, d: thickness of beam and t: thickness of face sheet). Beams tend to fail in ID mode when the thickness and strength of face sheet decreases. The CS mode may dominate failure when the thickness of core increases.

Effect of cell morphology on the compressive properties of open-cell aluminum foams

The mechanical properties of open-cell 6101 aluminum foams with different densities (∼5–10%) and morphologies (4–16 cells cm −1) were characterized in compression. It was found that density is the primary variable controlling the modulus and yield strength of foams. The effects of other variables such as cell size and shape were also studied. Whereas the cell size appears to have a negligible effect on the strength of foams, at a fixed density, the cell shape was shown to effect the strength of foams. In the present paper, theoretical models are offered to explain the differences in modulus and strength caused by the differences in cell shape and size.