D. Kakogiannis¹, D. Van Hemelrijck¹, J. Wastiels¹, S. Palanivelu², W. Van Paepegem², J. Vantomme³, A. Kotzakolios⁴, V. Kostopoulos⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.65, No.1, pp. 75-94, 2010, DOI:10.3970/cmes.2010.065.075

Abstract In the present study the estimation of the blast wave by two types of finite element methods is investigated: Eulerian multi-material modeling and pure Lagrangian. The main goal is to compare and study their ability to predict the clearing effect during blast. Element shape and improvements on the codes are also considered. For the Lagrangian finite element models the load is applied by using an empirical method, deriving from databases, for the time-spatial distribution of the pressure profiles. In the ideal case of the above method the blast load is applied as an equivalent triangular… More >

S. Ullah¹, B. Pichler¹, S. Scheiner^1,2, C. Hellmich^1,3

CMES-Computer Modeling in Engineering & Sciences, Vol.57, No.3, pp. 279-316, 2010, DOI:10.3970/cmes.2010.057.279

Abstract Point-wise optical measurements of 3D displacement vectors over time are a key input for monitoring shotcrete tunnel shells during construction according to the New Austrian Tunnelling Method (NATM). Aiming at estimation of the stresses prevailing in the highly loaded, hydrating material, we here deal with two different interpolation strategies for reconstructing, from measured displacement vectors, the 3D displacement field histories of the inner surface of the tunnel shell. The first approach considers spatial interpolation of displacement components in a fixed Cartesian base frame, while the second (new) approach refers to displacement components in a moving… More >

Michael Cox¹, John J. Klutke², Carl G. Klutke¹

Canadian Journal of Urology, Vol.16, No.2, pp. 4536-4540, 2009

Abstract Introduction and objective: Hunner's ulcer subtype interstitial cystitis (IC) is characterized by the presence of circumscribed inflammatory ulcerations in the bladder wall identified during endoscopic examination of individuals with irritative voiding symptoms and pelvic pain. We present our experience with management of this subgroup with intralesional submucosal injection of corticosteroid.
Methods: Prospective analysis of patients presenting with Hunner's ulcer subtype IC was performed between November 2006 and April 2008. All patients underwent flexible cystoscopy and biopsy confirming the presence of Hunner's ulcer(s). Under general anesthesia, 10 ml of triamcinolone acetonide (40 mg/ml) was injected in 0.5 ml… More >

N.H.M. Kamrujjaman Serker¹, Zhishen Wu

Structural Durability & Health Monitoring, Vol.5, No.2, pp. 87-108, 2009, DOI:10.3970/sdhm.2009.005.087

Abstract This paper presents the study on the temperature sensitivity of some vibration-based damage identification techniques. With the help of a simple supported beam with different damage levels, reliability of these techniques for damage identification in a changing environmental temperature condition was investigated. The temperature effect was considered as the change in modulus of elasticity of the material. The techniques evaluated herein are based on measured modal parameters which use only few mode shapes and/or modal frequencies of the structure that can easily be obtained by dynamic tests. The effect of temperature on identification of different More >

F. Fleissner¹, T. Haag², M. Hanss², P. Eberhard¹

CMES-Computer Modeling in Engineering & Sciences, Vol.52, No.2, pp. 181-196, 2009, DOI:10.3970/cmes.2009.052.181

Abstract In alpine regions human settlements and infrastructure are at risk to be hit by landslides or other types of geological flows. This paper presents a new approach that can aid the design of protective constructions. An uncertainty analysis of the flow around a debris barrier is carried out using a chute flow laboratory model of the actual debris flow. A series of discrete element simulations thereby serves to compare and assess two different barrier designs. In this study, the transformation method of fuzzy arithmetic is used to investigate the influence of epistemically uncertain model parameters. More >

Gang Lin¹, Yinghua Liu^1,2, Zhihai Xiang¹

CMES-Computer Modeling in Engineering & Sciences, Vol.47, No.3, pp. 217-252, 2009, DOI:10.3970/cmes.2009.047.217

Abstract Deterioration of reinforced concrete (RC) structures due to chloride ingress followed by reinforcement corrosion is a serious problem all over the world, therefore prediction of chloride profiles is a key element in evaluating durability and integrity of RC structures exposed to chloride environment. In the present paper, an integrated finite element-based computational framework is developed for predicting service life of RC structures exposed to chloride environment, which takes environment temperature and humidity fluctuations, diffusion and convection, chloride binding, as well as the decay of durability of structures caused by coupled deterioration processes into account. The… More >

Andrew J. Macnab, Lynn Stothers

Canadian Journal of Urology, Vol.15, No.5, pp. 4241-4248, 2008

Abstract Introduction: Near infrared spectroscopy (NIRS) is a non-invasive optical technique able to monitor changes in the concentration of oxygenated and deoxygenated hemoglobin in the bladder detrusor during bladder filling and emptying.
Objective: To evaluate the ability of a new NIRS instrument and algorithm to classify male patients with LUTS as obstructed or unobstructed based on comparison with classification via conventional invasive urodynamics (UDS).
Method: Male patients with LUTS were recruited and underwent uroflow and urodynamic pressure flow studies with simultaneous transcutaneous NIRS monitoring following measurement of post residual volume (PVR) via ultrasound. Data analysis first classified each subject… More >

C. Colombo¹, M. Guagliano^1,2, L. Vergani¹

Structural Durability & Health Monitoring, Vol.4, No.2, pp. 67-76, 2008, DOI:10.3970/sdhm.2008.004.067

Abstract With the aim of experimentally assessing the stress intensity factors under mixed-mode loading along a crack front, the case of an internal elliptical crack is analyzed. An experimental test is performed on a three-dimensional photoelastic model made in epoxy resin. This model contains an inner natural crack, created by thermal shock. The crack is inclined in the cylindrical model, loaded with a tensile stress field.
Exploiting the characteristics of the epoxy resin, and using the stress freezing technique, it is possible to keep memory of the stresses near to the crack tip, once the specimen is unloaded. More >

G. Papaioannou¹, C. Mitrogiannis¹, G. Nianios¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.2, pp. 41-46, 2008, DOI:10.3970/icces.2008.008.041

Abstract Previous attempts to track skeletal kinematics from sequences of images acquired using biplane dynamic radiography report challenges in automating the tracking technique due to image resolution issues, occlusion from segments appearing synchronously in the field of view and computational load. This translates into many hours of manual work to export the kinematics. The proposed new tracking method tackles the above problems and reduces the time to export kinematics from several hours to less than 3 minutes. More >

D. H. Pahr¹, H.J. Böhm¹

CMES-Computer Modeling in Engineering & Sciences, Vol.34, No.2, pp. 117-136, 2008, DOI:10.3970/cmes.2008.034.117

Abstract The combination of heterogeneous volume elements and numerical analysis schemes such as the Finite Element method provides a powerful and well proven tool for studying the mechanical behavior of composite materials. Periodicity boundary conditions (PBC), homogeneous displacement boundary conditions (KUBC) and homogeneous traction boundary conditions (SUBC) have been widely used in such studies. Recently Pahr and Zysset (2008) proposed a special set of mixed uniform boundary conditions (MUBC) for evaluating the macroscopic elasticity tensor of human trabecular bone. These boundary conditions are not restricted to periodic phase geometries, but were found to give the same… More >