01 Polyurethane Foams: Past, Present, and Future
02 Finite element modeling of compression behavior of extruded polystyrene foam using X-ray tomography
Extruded polystyrene rigid foams have attracted a great attention as a superior load- bearing thermal insulation material since their implementation in building construction. One of the most common application areas of this type of thermal insulation material is under raft foundations, where the foam normally undergoes high levels of compression loads.
The purpose of this research is to determine how to simulate and optimize the structural response of extruded polystyrene under compression stresses. The optimiza- tion has been achieved through investigating the relation between the foam microstruc- ture and the global mechanical properties. The foam was first examined using X-ray tomography imaging technique to acquire some morphological information about the microstructure. The obtained morphological data of extruded polystyrene boards were then utilized to develop microstructure-based finite element models based on the so- called idealized realistic Kelvin cell.
The finite element simulation was accomplished with the help of the nanoindentation technology to explore the mechanical properties of the cell wall material. The finite element models were validated by comparisons between the simulated and the experimental results. It has been found that the mechanical properties of the foam in different loading directions can be adequately simulated using the approach of the idealized realistic Kelvin cell. With the help of these models, a parameter study was carried out. This study included the effect of cell size and cell anisotropy on the mechanical response of extruded polystyrene boards under compression stresses. Charts relating between the foam microstructure characteristics and the compression behavior were generated based on the parametric study.
Extruded polystyrene rigid foams have attracted a great attention as a superior load- bearing thermal insulation material since their implementation in building construction. One of the most common application areas of this type of thermal insulation material is under raft foundations, where the foam normally undergoes high levels of compression loads.
The purpose of this research is to determine how to simulate and optimize the structural response of extruded polystyrene under compression stresses. The optimiza- tion has been achieved through investigating the relation between the foam microstruc- ture and the global mechanical properties. The foam was first examined using X-ray tomography imaging technique to acquire some morphological information about the microstructure. The obtained morphological data of extruded polystyrene boards were then utilized to develop microstructure-based finite element models based on the so- called idealized realistic Kelvin cell.
The finite element simulation was accomplished with the help of the nanoindentation technology to explore the mechanical properties of the cell wall material. The finite element models were validated by comparisons between the simulated and the experimental results. It has been found that the mechanical properties of the foam in different loading directions can be adequately simulated using the approach of the idealized realistic Kelvin cell. With the help of these models, a parameter study was carried out. This study included the effect of cell size and cell anisotropy on the mechanical response of extruded polystyrene boards under compression stresses. Charts relating between the foam microstructure characteristics and the compression behavior were generated based on the parametric study.
Finite element modeling of compression behavior of extruded polystyrene foam | |
File Size: | 1856 kb |
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03 Measurement of the Shear Properties of Extruded Polystyrene Foam by In-Plane Shear and Asymmetric Four-Point Bending Tests
The shear modulus and shear strength of extruded polystyrene foam were obtained by thein-plane shear and asymmetric four-point bending tests. In addition, the test data were numerically analysed, and the e ectiveness of these tests was examined.
The numerical and experimental results suggest that the shear modulus and shear strength obtained from the in-plane shear test are significantly smaller than those obtained from the asymmetric four-point bending test because the influence of the stress concentration was less significant.
Although the in-plane shear test is standardised in ASTM C273/ C273M-11, it is considerable to adopt the asymmetric four-point bending test as another candidate for obtaining the shear properties of extruded polystyrene foam.
The shear modulus and shear strength of extruded polystyrene foam were obtained by thein-plane shear and asymmetric four-point bending tests. In addition, the test data were numerically analysed, and the e ectiveness of these tests was examined.
The numerical and experimental results suggest that the shear modulus and shear strength obtained from the in-plane shear test are significantly smaller than those obtained from the asymmetric four-point bending test because the influence of the stress concentration was less significant.
Although the in-plane shear test is standardised in ASTM C273/ C273M-11, it is considerable to adopt the asymmetric four-point bending test as another candidate for obtaining the shear properties of extruded polystyrene foam.
measurement of the shear properties of extruded po.pdf | |
File Size: | 2950 kb |
File Type: |