Strain-iocalimtion instabilities due to strain-softening which result from distributed damage such (IS cracking in heterogeneous brittle materials are analyzed. Attention is restricted to the stability problem of equilibrium states. This problem is not equivalent to bifurcation of the equilibrium path. which may occur before stability of Lquilibrium is lost. The continuum is local but is enhunc...

Although most biomaterials are characterized by strong stiffness nonlinearities, the majority of studies of plant biomechanics and structural dynamics focus on the linear elastic range of their behavior. In this paper, the effects of hardening (elastic modulus increases with strain) and softening (elastic modulus decreases with strain) nonlinearities on the structural dynamics of plant stems ar...

Isothermal interrupted hot compression tests of 5754 aluminum were conducted on a Gleeble-3500 thermo-mechanical simulator at temperatures of 350 °C and 450 °C, and strain rates of 0.1 s−1 and 1 s−1. To investigate the metadynamic recrystallization behavior, a range of inter-pass delay times (5–60 s) was employed. These tests simulated flat rolling to investigate how softening behaviors respond...

The effect of thermal treatment on spruce is examined by analyzing the fracture and hygroscopic properties. Specimens were heated at temperatures within the range 120-200 °C for 1 h. Fracture energy was measured using a single-edge notched bending test and the strain-softening index was estimated by dividing the fracture energy by the maximum load. Adsorption properties were estimated using ads...

Many rubber like materials present a stress-softening phenomenon known as Mullins effect. It is characterized by a difference of behavior between the first and second loading and by a residual strain after a first loading. Moreover according to the literature this stress softening is anisotropic. A new constitutive equation is proposed. It relies on the decomposition of the macromolecular netwo...

This paper aims at studying the monotonic and cyclic plastic deformation behavior of DIN 34CrNiMo6 high strength steel. Monotonic and low-cycle fatigue tests are conducted in ambient air, at room temperature, using standard 8-mm diameter specimens. The former tests are carried out under position control with constant displacement rate. The latter are performed under fully-reversed strain-contro...

The rocks are formed through very complex processes and the complex behaviour of rock masses is dominated by the planes of weaknesses . Rock mass consists of intact rock and discontinuities. Many rocks show strain softening behaviour under loads. In this paper, the constitutive models for intact rocks and rock joints are presented. These form the basis for the development of constitutive models...

Passive mechanical properties of strips of rabbit detrusor smooth muscle were examined and found by cyclic loading in a calcium-free solution to display viscoelastic softening and strain-induced stress softening (strain softening). Strain softening, or the Mullins effect, is a loss of stiffness attributed to the breakage of cross-links, and appeared irreversible in detrusor even after the retur...

this paper presents a macro model to predict unreinforced masonry structures in plane behavior. the model is based on the concept of multilaminate theory. in the past, the method has been used to model behavior of soil, disregarding the cohesion and the tensile strength. regarding its mathematical base, and the possibility of applying in other cases, this method is used to predict the ultimate ...

AIMS Previous studies using isolated strips of human detrusor muscle identified adjustable preload tension, a novel mechanism that acutely regulates detrusor wall tension. The purpose of this investigation was to develop a method to identify a correlate measure of adjustable preload tension during urodynamics. METHODS Patients reporting urgency most or all of the time based on ICIq-OAB survey...