Local compression fatigue properties of peripherally clamped HSP have been studied in consideration of usage condition as a floor panel. In this study, the effect of cell wall thickness on local compression fatigue of HSP was clarified. For that purpose, a series of fatigue test of HSP was carried out by changing the cell wall thickness, the thickness of face sheet contacted the indenter and the maximum load value. When the cell wall thickness was thin, the fracture pattern of face sheet contacted the indenter changed from the tensile type to shearing type with the increase in the thickness of face sheet contacted the indenter. In the transitional region between these two fracture types, the only dent without crack was observed on the face sheet contacted the indenter. On the other hand, when the cell wall thickness was thick, the shearing fracture around dent was observed instead of the dent type in the transitional region. This was because of the increase of buckling strength of cell wall which constrained the formation of dent. This situation resulted in the increase in the shearing stress around the dent.
