Effect Of Structure Orientation Research Articles

Effect of structure orientation and debris initial orientation on peak debris loading during tsunami: An experimental and numerical investigation

The impact of the debris during extreme events is one of the major factors that has to be accounted for the critical design of the coastal structures. This study, investigates the effect of peak impact load due to combination of debris and the hydraulic bore on a structure with varying orientation angles. The bore profile is generated by using dam-break condition and a shipping container that is based on the ISO criteria fitted with an accelerometer, is used as a debris in this study. The peak impact load due to the combination of debris and the bore is measured by the multi-axial load cell that is mounted at the bottom of the modelled structure. It is observed that the orientation angle of the structure plays a major role in identifying the peak debris impact load. Therefore, a new coefficient of orientation angle, ‘Cθ’ is proposed to modify the basic impulse-momentum equation; that accounts for the excess loads on the structure. The experimental study is reproduced and simulated using particle based numerical method ‘δ-SPH’ and the results are validated with experimental observations. Further, the δ-SPH model is used to carry out detailed parametric study by varying the debris mass.

Unravelling the structural‐property relations of porphyrinoids with respect to photo‐ and electro‐chemical activities

AbstractPorphyrins have multiple roles in living and nonliving systems because of their exceptional tunable chemical and physical properties. They are interesting macrocyclic compounds that could be modified in a number of ways. The structural diversity of porphyrinoids make them a unique choice for functional devices exhibiting photo‐ and electrochemical properties. Their properties can be modified or altered by either protonating the nitrogen atoms or by inducing charge transfer to the metal center. Structural changes induced by flattening and planar distortions, redox reactions, solvents, and porphyrin aggregations also influence the photo‐ and electro‐chemical properties of porphyrinoids. This review gives a brief explanation on the effects of structural orientation, molecular structure, and charge on the properties of porphyrinoids. The review also illustrates the correlation between the geometrical features and the photo‐ and electrochemical behavior of porphyrinoids.

Probabilistic Modeling of Horizontal Wave-in-Deck Loads on a Square Concrete Deck

AbstractThe square concrete deck is being used as an elevated transition piece in offshore structure but has a large exposure area to extreme waves. This study focused on the horizontal wave-in-deck loads on the square concrete deck. Wave flume tests were carried out to investigate the wave-in-deck loads on a specimen of a square concrete deck. Horizontal wave-in-deck loads on the specimen with ten different structural orientations were measured under three nonlinear regular wave trains. A novel analytical model of the horizontal wave-in-deck loads on the square thick deck was proposed by including both impact maxima and pulse shape function. The temporal development of the resultant horizontal wave-in-deck loads was studied from the measured forces through data post-processing. The effects of structural orientation, inundation depth, and the correlation between the rise and decay time were considered based on the experimental data. The marginal distributions of the impact maxima and rise time for the horizontal wave-in-deck loads on the square deck were investigated, and the joint probability model of impact maxima and rise time was finally developed using Plackett copula. The research provides a useful stochastic model in assessing the wave-in-deck loads on the square concrete deck.

On the fracture mechanisms of nacre: Effects of structural orientation

The nacre of mollusk shells is distinguished by an exceptional mechanical efficiency which is derived essentially from its lamellar structure and frequently acts as a source of inspiration for the development of biomimetic materials. The structure and mechanical properties of nacre have been intensively investigated with a special focus on its toughening strategies; nevertheless, the fracture mechanisms, more specifically the critical stress/strain conditions for the failure of nacre, and the effects of structural orientation and hydration state remain largely unexplored. Here uniaxial compression tests were performed on nacre of both dry and hydrated states with different off-axis angles, i.e., the inclination of loading axis with respect to the lamellar structure, ranging from 0° to 90°. The mechanical properties and fracture characteristics of nacre and their dependences on the structural orientation and hydration state were elucidated in terms of mechanics behind failure. Quantitative relationships were established between the mechanical properties and off-axis angle based on different failure criteria. The competition between the fracture modes of fragmentation and shearing was quantified by comparing their respective driving force and resistance on the interfacial plane. This study may aid the understanding on the mechanical behavior of nacre and nacre-inspired synthetic materials and promote a better replication of the underlying design principles of nacre in man-made systems.

The Effects of Structure Orientation on the Growth of Fe<SUB>2</SUB>B Boride by Multi-Phase-Field Simulation

A morphological evolution of the growth of Fe2B boride on steel substrate has been investigated using two dimensional (2D) multi-phase-field (MPF) simulations. In order to evaluate competitive growth between boride seeds during the coating process, variations on boride seed orientation have been implemented. In addition, in order to have anisotropy growth of boride, anisotropy of interfacial energy is considered on the evaluation of phase-field evolution. It was observed that boride seed with structure orientation of 90° shows a preferential growth as compared with the growth of boride seeds at other orientations. On the other hand, competitive growth between boride seeds at different crystal orientations can also be observed, where boride seeds approaching a preferential orientation angle grow faster and suppress the growth of boride seeds at the lower orientation angle. Both of these present observations agree with previous experimental observations that boride seeds tend to grow perpendicular to the substrate surface and the growth of boride seeds in this direction suppress growth in other directions. Additionally, it was observed that the preferential growth of boride is independent of the initial size of the boride seed.

Effects of Structural Orientation on EDM Properties of Sapphire

Precise machining technologies of advanced insulating ceramics are demanded in many industrial fields. Normally Electric Discharge Machining (EDM) utilizes for electrical conductive materials. Recently, insulating materials have been succeeded to machine with the assisting electrode method (AEM) that was proposed by authors. Some ceramics were still recognized as hard materials. Especially the high purity oxide ceramics of Al 2 O 3 are difficult to machine for this method. Moreover single crystal Al 2 O 3 of sapphire (99.99%) is recognized as the hard machining material for the EDM method. In this paper, EDM of crystallographic planes on 3 different sapphires were carried out. The effects of the crystal orientation were discussed on the machining properties of sapphires.

Effect of structure orientation of the initial material on spall damages of the D16 and AMg6 alloys

Effect of structure orientation of the initial material on spall damages of the D16 and AMg6 alloys