in this paper, dynamic analysis of the composite truncated sandwich conical shells (stcs) with various boundary conditions subjected to low velocity impact was studied analytically, based on higher order sandwich panel theory. impact was assumed to occur normally over to the top face-sheet and the contact force history is predicted using two solution models of the motion are derived based on ha...

This study assessed the suitability of a new portable system that is based on Hertz's contact theory for evaluating internal gluteal muscle stresses under the ischial tuberosities of wheelchair users in real-time as a risk indicator for a deep tissue injury. Sitting in a wheelchair was monitored and processed with the portable system for six control subjects and five individuals with paraplegia...

We develop an analytical theory of adhesive interaction of viscoelastic spheres in quasistatic approximation. Deformations and deformation rates are assumed to be small, which allows for the application of the Hertz contact theory, modified to account for viscoelastic forces. The adhesion interactions are described by the Johnson, Kendall, and Roberts theory. Using the quasistatic approximation...

Due to disorder, contacts between beads in stressed granular assemblages are not equally loaded. There exists a distribution of contact static loads, containing weakly loaded contacts (the weak contacts) and strongly loaded contacts (the strong contacts involved in the so-called force chains). For an elastic periodic excitation with a given deformation amplitude, the weakest contacts are suppos...

We address three problems that limit the use of the atomic force microscope when measuring elastic moduli of soft materials at microscopic scales. The first concerns the use of sharp cantilever tips, which typically induce local strains that far exceed the linear material regime. We show that this problem can be alleviated by using microspheres as probes, and we establish the criteria for their...

Slewing bearings are critical components of rotating equipment. Large structure sizes and heavy working load conditions require an extremely high load-bearing capacity reliability. Overall local contact finite element models slewing verified by the empirical formula Hertz theory. Validated used to analyse influence elastic material (E 1) elastoplastic parameters (EP 1, EP 2 3) on carrying capac...

We report on the elastic contact between a spherical lens and a patterned substrate, composed of a hexagonal lattice of cylindrical pillars. The stress field and the size of the contact area are obtained by means of numerical methods: a superposition method of discrete pressure elements and an iterative bisection-like method. For small indentations, a transition from a Hertzian to a soft-flat-p...

This paper proposes a modified tangential contact stiffness model considering friction’s effect, which is the first key step to establish dynamic of fixture-workpiece system, and this foundation vibration suppression for manufacturing process aerospace blades. According Love’s elastic deformation, model’s derivation starts with potential function in each coordinate axis’s direction respectively...