Static and fatigue data available in literature concerning carbon fiber reinforced composite laminates subjected tension-tension fatigue were re-elaborated in the framework of a two-parameter fatigue model explicitly accounting for the cyclic as well as the mean stress. The data were used to obtain the model parameters by best fitting procedures. A primitive statistical implementation of the mo...

Concrete is a material whose performance is governed by the subtle interaction of its cohesive and frictional constituents. Since the theories of plasticity, damage mechanics, and fracture mechanics cannot, by themselves, capture both of these phenomena, a novel constitutive model is proposed which combines the theories of plasticity and damage mechanics in a multi-surface formulation. Synthesi...

Abstract In this work, cast steel G17CrMoV5-10 was investigated. The material subject to investigation as part of study is commonly used manufacture steam turbine casings. Modern turbines operate under elevated temperature and complex oscillated loads. Thus, the focus investigate behavior during low cycle fatigue (LCF) test performance at 500°C with without hold time in tension. During all type...

Room temperature monotonic and cyclic stress–strain curves for single crystal and polycrystalline NiTi shape memory alloys containing Ti3Ni4 precipitates are presented. The tensile and compressive single crystal results illustrate the importance of crystallographic texture, the unidirectional nature of the martensitic transformation, and martensite detwinning on tension-compression stress–strai...

Large-strain monotonic and cyclic loading tests of AZ31B magnesium alloy sheets were performed with a newly developed testing system, at different temperatures, ranging from room temperature to 250 °C. Behaviors showing significant twinning during initial in-plane compression and untwinning in subsequent tension at and slightly above room temperature were recorded. Strong yielding asymmetry and...

BACKGROUND Mechanical ventilation may induce harmful effects in the airways of critically ill patients. Nevertheless, the effects of cyclic stretching caused by repetitive inflation-deflation of the bronchial compartment have not been well characterized in humans. The objective of the present study was to assess the effectiveness of a load-imposing device for the cyclic stretching of human bron...

Nebulin (NEB) is a large, rod-like protein believed to dictate actin thin filament length in skeletal muscle. NEB gene defects are associated with congenital nemaline myopathy. The functional role of NEB was investigated in gastrocnemius muscles from neonatal wild-type (WT) and NEB knockout (NEB-KO) mice, whose thin filaments have uniformly shorter lengths compared with WT mice. Isometric stres...

Enzymatic treatments were applied to rat motion segments to establish structure-function relationships and determine mechanical parameters most sensitive to simulated remodeling and degeneration. Rat caudal and lumbar disc biomechanical behaviors were evaluated to improve knowledge of their similarities and differences due to their frequent use during in vivo models. Caudal motion segments were...

and Martha Vaughan, M.D. T he increase in O tension to which the human umbilical artery is exposed at birth acts in at least two separate but related ways to initiate closure of the vessel. Oxygen itself directly induces constriction.’ It plays further a “permissive” role in the action of other chemical agents that cause contraction.’ The relationship between elevated Po and contraction is beli...

Elastomeric materials experience stretch-induced softening as evidenced by a pre-stretched material exhibiting a signi1cantly more compliant response than that of the virgin material. In this paper, we propose a fully three-dimensional constitutive model for the observed softening of the stress–strain behavior. The model adopts the Mullins and Tobin concept of an evolution in the underlying har...