Needle deflection in thermal ablation procedures of liver tumors: a CT image analysis

Introduction: Accurate needle placement is crucial in image-guided needle interventions. A targeting error may be introduced due to undesired needle deflection upon insertion through tissue, caused by e.g. patient breathing, tissue heterogeneity, or asymmetric needle tip geometries. This paper aims to quantify needle deflection in thermal...

Beam Experiments on Acceptance Criteria for Bridge Load Tests

Loading protocols and acceptance criteria are available in the literature for load tests on buildings. For bridges, proof load tests are interesting when crucial information about the structure is missing, or when the uncertainties about the structural response are large. The acceptance criteria can then be applied to evaluate if further loading...

Extreme bendability of DNA double helix due to bending asymmetry

Experimental data of the DNA cyclization (J-factor) at short length scales exceed the theoretical expectation based on the wormlike chain (WLC) model by several orders of magnitude. Here, we propose that asymmetric bending rigidity of the double helix in the groove direction can be responsible for extreme bendability of DNA at short length...

Mechanical Behaviour of Lined Pipe

Installing lined pipe by means of the reeling installation method seems to be an attractive combination, because it provides the opportunity of eliminating the demanding welds from the critical time offshore and instead preparing them onshore. However, reeling of lined pipe is not yet proven technology. From previous research it is known that...

Proximity effect in ion-beam-induced deposition of nanopillars

Ion-beam-induced deposition (IBID) is a powerful technique for prototyping three-dimensional nanostructures. To study its capability for this purpose, the authors investigate the proximity effect in IBID of nanopillars. In particular, the changes in shape and dimension of pillars are studied when a second pillar is grown near an existing pillar....

Nanomechanical properties of few-layer graphene membranes

We have measured the mechanical properties of few-layer graphene and graphite flakes that are suspended over circular holes. The spatial profile of the flake’s spring constant is measured with an atomic force microscope. The bending rigidity of and the tension in the membranes are extracted by fitting a continuum model to the data. For flakes...

Timber-concrete composite beams

In this paper an easy-to-use design model for timber-concrete composite beams is discussed. The model is applicable for computer simulations as well as for hand calculations. A research programme was started in 1992 in co-operation with the University of Karlsruhe, to study the loadbearing capacities of timber-concrete composite beams that are...

Collapse of anisotropic cylindrical shells under combined bending and transverse shear load

Damage tolerance analyses of bolt/nut assemblies

Probably one of the most challenging problems in fracture mechanics is related to its application to fastener and joints. By nature, not only the quality such as material, manufacturing and mounting processes, of the fasteners are playing a role, but also the stiffness, surface conditions and geometry of the parts are to be considered. Moreover,...

Application of the virtual crack closure technique to calculate stress intensity factors for through cracks with an oblique elliptical crack front

Fatigue Rated Fastener Systems: an AGARD coordinated testing programme

The report contains the description, results and conclusions of a fatigue test programme which assessed the fatigue lives of fastener systems using different joints. High load transfer single shear joints were evaluated in a core programme; secondary bending and load transfer were determined experimentally. About 750 specimens were fatigue...