Material properties and geometry are two important design parameters which their effects should be considered in a crashworthiness analysis. In this paper, the axial impact of metallic and hybrid energy absorbing thin-walled tubes with poly-gonal cross-section is simulated using LS-DYNA software. The combined effects of changing the geometry and material properties on the mass specific energ...

using cold working fastener holes is a simple life enhancement procedure that strengthens metallic components by retarding crack growth around a hole. in the present paper, the residual stress field that is induced by the hole expansion process is obtained based on different material models namely elastic perfect plastic, isotropic hardening and kinematic hardening using three-dimensional finit...

To establish which factors influence performance and bird welfare during a fattening period and to identify those factors to be investigated during routine monitoring of farms by veterinary authorities, a questionnaire-based field study was conducted in districts of Lower Saxony, Germany, with the highest density of broiler chickens. Mortality and BW of farms with different stocking densities (...

Recent theoretical and computational progress has led to unprecedented understanding of symmetry-breaking instabilities in 2D dynamic fracture. At the heart this resides identification two intrinsic, near crack tip length scales -- a nonlinear elastic scale $\ell$ dissipation $\xi$ that do not exist classical theory cracks. In particular, it been shown at high propagation velocity $v$, cracks b...

OBJECTIVE In a prospective pilot study, short< or =10 mm ITI-SLA implants were placed in the resorbed posterior maxilla by means of an osteotome sinus floor elevation (OSFE) procedure without grafting material. This paper presents 3-year data assessing bone-level changes around implants. MATERIAL AND METHODS Twenty-five implants were placed in 17 patients to rehabilitate 16 molar and nine pre...

BACKGROUND Our study investigated the readability of printed material about dementia that is offered to patients and caregivers. METHODS Comparisons of various brochures (at least three standard pages in length) on dementia and related disorders were made using automated measuring by the SMOG readability index grade. RESULTS 118 brochures were assessed (25 in English, 93 in German), for whi...

BACKGROUND Musculotendinous stiffness provides an estimate of resistance to joint perturbation, thus contributing to joint stability. Females demonstrate lesser hamstring stiffness than males, potentially contributing to the sex discrepancy in anterior cruciate ligament injury risk. However, it is unclear if the sex difference in hamstring stiffness is due to differences in muscle size or to in...

An extension of the celebrated Paris law for crack propagation is given to take into account some of the deviations from the power-law regime in a simple manner using the Wöhler SN curve of the material, suggesting a more general ‘‘unified law’’. In particular, using recent proposals by the first author, the stress intensity factor K(a) is replaced with a suitable mean over a material/structura...

wide range of planar structures in new technologies has attracted special consideration. in this research vibration behavior of plates with non-linear edges is investigated by means of finite difference (fd) method. for this issue, classical and analytical solutions for plates with linear edges were analyzed and mutual equations, needed for numerical calculation were extracted. by expanding the...

Depending on the geometric basis of measurement (gauge length), discrete strain sensors used in structural monitoring of civil engineering structures can be considered as short-gauge sensors or long-gauge sensors. Long-gauge sensors measure average strain over the gauge lengths and are used for global monitoring of structures, in particular, those built of inhomogeneous materials. However, the ...