The behavior of sand crushing will appear when the confining pressure is up to a certain value, which results in disappearing of the positive dilatancy of sand. Adopting a new hardening parameter with the crushing stress, an elastoplastic constitutive model considering sand crushing is proposed. Comparing the conventional triaxial compression test results with the model prediction, it shows tha...

OBJECTIVE This study aimed to quantify the specific effects of manual lung inflations with chest compression-vibrations, commonly used to assist airway clearance in ventilated patients. The hypothesis was that force applied during the compressions made a significant additional contribution to increases in peak expiratory flow and expiratory to inspiratory flow ratio over and above that resultin...

BACKGROUND Knee osteoarthritis is common in people who have undergone partial meniscectomy, and a higher external knee flexion moment during gait may be a potential contributor. Although the peak external knee flexion moment has been shown to increase from 3 months to 2 years following partial meniscectomy, mechanisms underpinning the increase in the peak knee flexion moment are unknown. METH...

The beetle’s elytra have the characteristics of light weight and high energy absorption (EA). In this paper, based on internal structure beetle elytra, two bio-inspired honeycomb column thin-walled structures (BHTS) I II were fabricated by selective laser melting (SLM) technology in additive manufacturing (AM) order to understand possible influence strain rate effect (SRE) BHTS under low speed ...

OBJECTIVE The introduction of shoulder pads has coincided with a rise in shoulder impact injuries in the game of rugby. In this study, the effect of shoulder pads on impact force attenuation was quantified. DESIGN Four different commercially available shoulder pads were tested for material properties. Hard and soft objects were dropped from predetermined heights onto a force plate imparting p...

This paper explores the effect of particle breakage on mechanical behavior coarse sand through 3D Discrete Element Method (DEM) simulations direct shear tests (DST). The objective is to gain insights into macro- and micro-mechanical behaviors crushable sand, with a particular focus stress–strain relationship, volumetric deformation, evolution grain crushing. involve comparison between non-crush...

The purpose of this study was to better understand how lower body kinematics relate to peak glenohumeral compressive force and develop a regression model accounting for variability in peak glenohumeral compressive force. Data were collected for 34 pitchers. Average peak glenohumeral compressive force was 1.72% ± 33% body weight (1334.9 N ± 257.5). Correlation coefficients revealed 5 kinematic v...

Impact forces and shock deceleration during jumping and running have been associated with various knee injury etiologies. This study investigates the influence of jump height and knee contact angle on peak ground reaction force and segment axial accelerations. Ground reaction force, segment axial acceleration, and knee angles were measured for 6 male subjects during vertical jumping. A simple s...

The purpose of this study was to choose between two popular models of skeletal muscle: one with the parallel elastic component in parallel with both the contractile element and the series elastic component (model A), and the other in which it is in parallel with only the contractile element (model B). Passive and total forces were obtained at a variety of muscle lengths for the medial gastrocne...