A new test procedure to validate tensile dynamic mechanical properties of sheet metals and alloys in automotive crash applications

A thin walled open channel beam subjected to a 3-point bend and constant velocity boundary condition is investigated to establish its potential to validate material performance for automotive crash applications. Specifically quantitative validation of material data determined from high speed tensile testing and qualitative validation of material resistance to fracture in crash components. Open channel beams are fabricated from structural grade sheet steel and aluminium alloy and tested at quasi-static and higher speeds up to 10 m/s and in all cases, deformation develops a plastic hinge. This paper describes development of the validation test procedure, specifically design of specimen, system of measurement and boundary conditions using numerical and experimental techniques. The new test procedure will increase confidence in materials modelling and reduce the risk to introduce new advanced high strength materials into automotive crash structures

Modelling self-piercing riveted joint failures in automotive crash structures

This paper describes a new model and method to predict Self-Piercing Riveted (SPR) joint interlock failures in aluminium sheet at crash speeds using explicit finite element simulation. SPR interlock failure is dependent on rivet direction, which is included in the model. A mesh independent approach is adopted for connection model which is capable of industrial application at the full vehicle crash analysis level. The paper provides an overview of the approach to validate connection model; typically by developing detailed physics based models of various joint configurations supported with high speed experimental data, through to model capable of industrial application. The framework to validate connection model for use in crash simulation tools is expected to have broader applicatio

The search for exudates from Eurasian watermilfoil and hydrilla

Secondary metabolites are produced by aquatic plants, and in some instances, exudation of these metabolites into the surrounding water has been detected. To determine whether infestations of Eurasian watermilfoil or hydrilla produce such exudates, plant tissues and water samples were collected from laboratory cultures and pond populations and were analyzed using solid phase extraction, HPLC, and various methods of mass spectrometry including electrospray ionization, GC/MS, electron impact and chemical ionization. Previously reported compounds such as tellimagrandin II (from Eurasian watermilfoil) and a caffeic acid ester (from hvdrilla), along with a newly discovered flavonoid, cyanidin 3 dimalonyl glucoside (from hydrilla), were readily detected in plant tissues used in this research but were not detected in any of the water samples. If compounds are being released, as suggested by researchers using axenic cultures, we hypothesize that they may be rapidly degraded by bacteria and therefore undetectable

Validating dynamic tensile mechanical properties of sheet steels for automotive crash applications

A thin-wall open channel beam, fabricated from high strength Dual Phase sheet steel, subjected to 3-point bending and constant velocity boundary condition, is investigated to validate material performance for automotive crash applications. Specifically quantitative validation of material tensile data determined from high speed tests and component models, and qualitative validation of materials resistance to fracture. The open channel beam is subjected to quasi-static and increasing loading speed and in all cases, large displacement in which deformation involves formation of a plastic hinge. This paper describes development of test procedure, notably beam specimen design, measurement system and boundary conditions, using both experimental and numerical techniques. The new test procedure, as a compliment to crush testing, will increase confidence in the modeling and application of new advanced higher strength materials in automotive crash structure

Validating performance of automotive materials at high strain rate for improved crash design

This paper investigates sources of performance variability in high velocity testing of automotive crash structures. Sources of variability, or so called noise factors, present in a testing environment, arise from uncertainty in structural properties, joints, boundary conditions and measurement system. A box structure, which is representative of a crash component, is designed and fabricated from a high strength Dual Phase sheet steel. Crush tests are conducted at low and high speed. Such tests intend to validate a component model and material strain rate sensitivity data determined from high speed tensile testing. To support experimental investigations, stochastic modeling is used to investigate the effect of noise factors on crash structure performance variability, and to identify suitable performance measures to validate a component model and material strain rate sensitivity data. The results of the project will enable the measurement of more reliable strain rate sensitivity data for improved crashworthiness predictions of automotive structures

Russian approaches to energy security and climate change: Russian gas exports to the EU

The proposition that EU climate policy represents a threat to Russia’s gas exports to the EU, and therefore to Russia’s energy security, is critically examined. It is concluded that whilst the greater significance of climate-change action for Russian energy security currently lies not in Russia’s own emissions reduction commitments but in those of the EU, an even greater threat to Russia’s energy security is posed by the development of the EU internal gas market and challenges to Russia’s participation in that market. However, the coming decades could see Russia’s energy security increasingly influenced by climate-change action policies undertaken by current importers of Russian gas such as the EU, and potential importers such as China and India. The challenge for Russia will be to adapt to developments in energy security and climate-change action at the European and global levels

Validating material information for stochastic crash simulation

This paper describes the steps in validating material information for stochastic simulation using a quasi static tensile test experiment Sources of physical noise usually present in a testing environment such as variation in material properties, geometry and boundary conditions are included as inputs to finite element models

Термінові одночасні гастро-ренальні ефекти води Нафтуся та їх вегето-гуморальний аккомпанемент. Повідомлення 2: Кластеризація на основі квалітативних варіантів ефектів на рН шлункового соку

Выделено 7 кластеров-вариантов качественных срочных эффектов биоактивной воды Нафтуся на базальный рН желудочного сока: переход нормоацидности в субацидностъ (4% больных); снижение кислотности в пределах нормоацидности (13%); повышение кислотности в пределах нормоацидности (25%); переход нормоаиидности в гиперацидность (16%); трансформация анацидности в субацидностъ (22%) или в нормоацидность (8%) при отсутствии существенных изменений щелочных значений рН у 10% обследованных. Прослежены сопутствующие изменения других параметров желудочной секреции, а также диуреза и салуреза, электролитемии, вегетативной нервной и гастроэнтеро-панкреатической эндокринной систем. Продемонстрирована возможность 'прогнозирования перечисленных эффектов по совокупности 14 базальных параметров, отобранных методом дискриминантного анализа.It is established 7 clusters-variantes of qualitativ immediate effects of water Naftussya on basal pH of gastric juice. By using method of discriminant analysis it is detected 14 basal parameters of gastroentero-pancreatic endocrine and vegetativ nervous systems, plasma electrolithes, secretory and evacuatory functions of stomach and diuretic and saluretic functions of kidney thouse conditionizes definite variant of effects

Diamond like carbon coatings for potential application in biological implants – a review

Production of wear debris has been linked to the failure of numerous hip implants. With the current focus on increasing the implant longevity, thus wear and corrosion resistance is important. Hard coatings have the potential to reduce the wear and corrosion. Diamond like Carbon (DLC) coatings exhibit properties that could make them viable for implants. This paper critically reviews previously published research into usage of DLC coatings for implants. Overall DLCs seem to be an effective coating for implants but with the variance in results, further testing is required for clarification of us

Construction of simplified design <i>p-y</i> curves for liquefied soils

In practice, laterally loaded piles are most often modelled using a ‘Beam-on-Nonlinear-Winkler-Foundation’ (BNWF) approach. While well calibrated p-y curves exist for non-liquefied soils (e.g. soft clay and sands), the profession still lacks reliable p-y curves for liquefied soils. In fact, the latter should be consistent with the observed strain-hardening behaviour exhibited by liquefied samples in both element and physical model tests. It is recognised that this unusual strain-hardening behaviour is induced by the tendency of the liquefied soil to dilate upon undrained shearing, which ultimately results in a gradual decrease of excess pore pressure and consequent increase in stiffness and strength. The aim of this paper is twofold. First it proposes an easy-to-use empirical model for constructing stress-strain relationships for liquefied soils. This only requires three soil parameters which can be conveniently determined by means of laboratory tests, such as a cyclic triaxial and cyclic simple shear tests. Secondly, a method is illustrated for the construction of p-y curves for liquefiable soils from the proposed stress-strain model. This involves scaling of stress and strain into compatible soil reaction p and pile deflection y, respectively. The scaling factors for stress and strain axis are computed following an energy-based approach, analogous to the upper-bound method used in classical plasticity theory. Finally, a series of results from centrifuge tests are presented, whereby p-y curves are back-calculated from available experimental data and qualitatively compared with that proposed by the authors