The influences of elevated and cryogenic temperature on the quasi-static indentation responses and damage mechanism for composite Y-type cores sandwich structure were studied by experiments in present paper. The quasistatic indentation experiments were performed to explore the indentation performances for composite Y-type cores sandwich structures under eight different temperature conditions. The influences of the testing environment temperature on the typical indentation force-deformation curves, damage patterns and indentation failure load were investigated and analyzed. The experimental results demonstrated that the testing environment temperature made an important influence on the deformation mechanism, typical forcedeformation curves and failure load. Fiber fracture of the front panel was found when the testing environment temperature was below the glass transition temperature, while the fiber microbuckling of the front panel was also revealed when the testing environment temperature was above the glass transition temperature. The failure load increased with the decreasing of the testing environment temperature at cryogenic temperature. Nevertheless, at elevated temperature, the failure load decreased with the increasing of the testing environment temperature attributing to the weakening of the fiber-matrix interface performances.

High long-term stress on the plantar fascia (PF) is the main cause of plantar fasciitis. Changes in the midsole hardness (MH) of running shoes are an important factor leading to the alteration of the PF. This study aims to establish a finite-element (FE) model of the foot–shoe, and investigates the effects of midsole hardness on PF stress and strain. The FE foot–shoe model was built in ANSYS using computed-tomography imaging data. Static structural analysis was used to simulate the moment of running push and stretch. Plantar stress and strain under different MH levels were quantitatively analyzed. A complete and valid 3D FE model was established. With an increase in MH from 10 to 50 Shore A, the overall stress and strain of the PF were decreased by approximately 1.62%, and the metatarsophalangeal (MTP) joint flexion angle was decreased by approximately 26.2%. The height of the arch descent decreased by approximately 24.7%, but the peak pressure of the outsole increased by approximately 26.6%. The established model in this study was effective. For running shoes, increasing the MH reduces the stress and strain of PF, but also imposes a higher load on the foot.