Abstract A simple method is proposed to model the open cracked beam structures. In this method, crack is modeled as a beam element. Hence cracked beam can be assumed to be a beam with stepped cross sections, and problem of determining natural frequency and mode shape of cracked beam, can be solved as determining these characteristics for a beam with different length and cross section. With this...

In order to check and eliminate the cracked eggs quickly and exactly in the process of egg products, a nondestructive testing system for eggshells based on digital signal processor (DSP) was established. The system utilized a TMS320VC33 DSP as a hardware platform, and has many functions such as controlling knock-equipment, sampling and processing the acoustics signals, judging the cracked-shell...

Cracked and un-cracked Brazilian disc specimens subjected to diametral compression were used for conducting fracture toughness and tensile strength experiments on a polymer concrete (PC) material. The value of mode I fracture toughness (KIc) was determined from the center- cracked Brazilian disc and the indirect tensile strength (σt) was obtained from the un-cracked Brazilian disc specimen. The...

A repeated thermomechanical treatment (RTMT) was adopted to control the microstructure of a glass-balloon-dispersed aluminum alloy (AC3A) composite. The RTMT, which involves the repetition of a multi-step process and followed by heat treatment, was applied to a cast plate of the composite. The composite was successfully worked into a rod or sheet by either swaging or flat rolling. The porous gl...

A multiscale (micro-macro) approach is proposed for the establishment of the full thermal and induced stress fields in cracked composites that are subjected to heat flow. Both the temperature and stresses distributions are determined by the solution of a boundary value problem with one-way coupling. In the micro level and for combined thermomechanical loading, a micromechanical analysis is empl...

The presence of part-through cracks with limited length is one of the prevalent defects in the plate structures. Due to the slight effect of this type of damages on the frequency response of the plates, conventional vibration-based damage assessment could be a challenging task. In this study for the first time, a recently developed state-space method which is based on the chaotic excitation is ...

In this paper, several transversely cracked RC beams, self-anchored in a three-point bending mode, were prepared and subjected to NaCl solution drying–wetting cycles. Based on two experimental results obtained after 15 and 30 cycles, respectively, the profiles of free chloride concentration at different sections of sound and cracked concretes were presented and analyzed. The depth of surface co...

PURPOSE To provide an overview of the clinical features, diagnosis, classification and management of cracked teeth which may be a diagnostic challenge in clinical practice. RESULTS Cracks may initiate from coronal tooth structure or from within the root and affect healthy or root treated teeth. There are many terminologies and classifications in the literature for cracked teeth that can be as...

BACKGROUND To assess the prevalence and factors associated with the occurrence of cracked nipples in the first month postpartum. METHODS This was a cross-sectional study nested in a cohort of mothers living in Feira de Santana, state of Bahia, northeastern Brazil. Data from 1,243 mother-child dyads assessed both at the maternity ward and 30 days after delivery were analyzed. The association b...