Wavy Shape Research Articles

The inner structure and kinematics of the Zvizdal-Zalisk and Brusyliv fault zones of the Ukrainian shield by the results of tectonophysical, magnetometrical data

In 2021, the tectonophysical measurements of cracking, structural-textural elements of rocks near Malyn, Radomyshl, Pohrebyshche, Buky, Kashperivka and magnetometric field studies of Zvizdal-Zalisk dyke were carried out. And also the deep seismic sounding data along II and VI geotravers were analyzed in order to purpose to finding out of the internal structure and kinematics of Zvizdal-Zalisk and Brusyliv fault zones of the Ukrainian Shield.
 According to our tectonophysical data, the studied rocks were formed under landslide deformation processes with alternating sublatitudinal and submeridional compression regimes, which correspond to the youngest Subbottsi-Moshoryn stage of faulting formation within the Ukrainian Shield (1.80—1.77 Ga), with subhorizontal axes of compression σ1 — 315° and tensile σ3 — 45°. Cracks and bands of gneisses of moderate dip are also widely developed in the study area. Established, that it has deformation throw regime with σ1 — 100/85°, σ3 — 280/05°, σ2 — 10/02°. Authors of article associate this deformation with formation of the main breeds Zvizdal-Zalisk dikes. Deformations of the Nemyriv faulting stage (1.99 Ga) were fixed at the intersection node of the Zvizdal-Zalisk faulting zone with Nemyriv fault zone (1.99 Ga). Stress field is σ1 — 301°, σ3 — 31° at the intersection node the Brusyliv fault zone with Nemyriv fault zone and it repeat main deformation strains of the Novograd-Volyn and Uman massifs (~2.05 Ga).
 By the data of the deep seismic sounding along II and VI Geotraverses, the Zvizdal-Zalisk fault zone enters the mantle all along, in the north and in the south. The crust structure in the study area has two layers of upper crust (VР=5,9–6,4 km/s),with intermittent low- (5,8—6,2 km/s) and high-velocity (6,3—6,9 km/s) horizons, the middle crust (6,4—6,9 km/s), and lower crust (6,9—7,0 km/s) that has a wavy dome-like shape with high differentiated velocity picture differing on both sides of the Central faulting area. The Bug megablock has a dome-like structure along all VI Geotraverse and is divided in half by the Zvizdal-Zalisk fault zone at the Moho discontinuity according to the data of the tomographic inversion along the velocity change gradient.
 By the magnetometric data, the Zvizdal-Zalisk fault zone lies almost fully within the regional minimum of the magnetic field (∆В)а,reg, which encompasses areas of the crust with minimum values of magnetization. The dyke was formed at the same time of the Korosten pluton formation and at activation of the Zvizdal-Zalisk fault zone. Its small depth confirms its crust origin; the variable sharp incline of the dyke’s parts is evidence of its subvertical falling which corresponds to the vertical position of the Zvizdal-Zalisk fault zone.
 The data on the chemical-mineralogical composition and position of mineral deposits suggest that the main regional structures which have influenced the metallogenic specialization of the region are the Zvizdal-Zaliska, Brusyliv, Nemyriv, Khmelniksk, Central, and Sarnensko-Varvarivka fault zones.

Investigating thermo-hydraulic behavior of pillow plate heat exchangers using entropy generation approach

Pillow plate heat exchanger (PPHE) is a modern type of plate heat exchanger composed of wavy shape parallel plates. Adjustment of the geometrical parameters has been broadly made to enhance the heat transfer performance of PPHEs. However, there has been limited attention to the thermo-hydraulic features and entropy generation of fluid flow through such heat exchangers. Addressing this gap could help further understanding of such heat exchangers. In the present study, Ansys CFX is used to simulate turbulent flow and heat transfer in inner pillow plate channels. The local entropy generation due to thermal effects and friction is calculated as a post processed task. The influence of the channel height, Prandtl number, diameter and arrangement of spot welds on the overall entropy generation of pillow plates are analyzed. The results indicate that by increasing the channel height, thermal entropy generation increases. Besides, increasing the spot weld diameter leads to a higher frictional loss in pillow plate channels, while the effect of spot weld size on thermal entropy generation is negligible. Also, the spot weld arrangement significantly affects the thermal and hydraulic characteristics of PPHEs. The results show that exergy analysis can be considered as a potential tool for investigating thermo-hydraulic behavior of PPHEs.

Corrugated shells: An algorithm for generating double-curvature geometric surfaces for structural analysis

Analysis of corrugated shell structures is an interesting problem in Structural Mechanics, which has many practical applications in Civil Engineering and Architecture. Thanks to corrugation, these structures have a remarkable feature: the wavy (undulated) shape in their edge provides significant enhancements in their structural behaviour, increasing the bending stiffness at the edge and allowing for a non-negligible reduction of its thickness. Moreover, looking at the non-linear behaviour, domes corrugation plays a relevant role in instability phenomena, such as the influence of imperfections and increasing resistance to snap-through.A problem in the study of such kind of shells is the definition of mathematical and geometrical model and the construction of a suitable mesh to perform FE analyses. The aim of this paper is to find an automated way to generate a double-curvature geometric surface that can be used both in static and in non-linear stability analyses of such corrugated shell structures. A method to generate a NURBS surface, suitable for a parametric FE analysis from a geometrical model expressed in a parametric form, is proposed and applied to a shell inspired by the well-known dome designed by Pier Luigi Nervi in 1959 for the roof of the Palasport Flaminio in Rome.

Periodic behavior of reflectance and transmittance from a thin film due to optical interference; The case of AlN nanostructure films

In most spectrums taken from thin films, periodic transmittance and reflectance patterns are visible. This effect, which is due to interference between the reflected beams from both sides of the thin film, contains important information about the optical properties of the film. In this paper, which is an extension of the Swanepoel and previous models, we additionally provide more accurate mathematical model of the optics of this phenomenon and simulation of the spectra, resulting in more accurate absorption coefficient and refractive index values. Also, for the first time, a precise mathematical formula for the wavy shape of transition was obtained and tested. Experiments were performed to test the model on aluminum nitride (AlN) thin films, which were fabricated by the sputtering method and are of increasing interest because of their reproducibility and scalability. A bottleneck challenge is to get a crack-free and rough thin film with high transmission. AlN thin films with different thicknesses were deposited on glass substrates, with grain sizes of less than 10 nm. The structural and topological properties were investigated with scanning electron microscopy and atomic force microscopy (AFM). The optical properties of the films, such as transmission and reflection were compared with the numerical method.

Analytical Estimation of Electromagnetic Pressure, Flyer Impact Velocity, and Welded Joint Length in Magnetic Pulse Welding

Magnetic pulse welding involves the joining of two metallic parts in a solid state by the use of a short and intense electromagnetic impulses and the resulting impact between the parts. The coalesced interface undergoes visco-plastic deformation at a high strain rate and exhibits a wavy shape at a microscopic scale. A practical estimation of the electromagnetic pressure, impact velocity and welded joint length as a function of the process conditions and the electromagnetic coil geometry is required but currently not available. Three novel analytical relations for the estimation of the electromagnetic pressure, impact velocity, and welded joint length for magnetic pulse welding of tubes and sheets, are presented. These relations were developed systematically, following a dimensional analysis, and validated for a wide range of conditions from independent literature. The comparison of the analytically computed results and the corresponding values reported in the literature has illustrated that the proposed analytical relations can be used for the estimation of the electromagnetic pressure and impact velocity for the magnetic pulse welding of tubes and sheets with a good level of confidence. The analytically calculated results for the welded joint length show a little discrepancy with the corresponding experimentally measured values. Further investigations and more experimentally measured results are required to arrive at a more comprehensive analytical relation for the prediction of welded joint length.

Influence of valve effect on energy efficiency of layer gasdynamic systems

The direction of gas movement and the properties of the granular layer, which must be taken into account in the Darcy-Weisbach formula, have a significant effect on the energy efficiency of gas-dynamic processes in layered systems. The complex form of the regularity of the coefficient of resistance from the content of fine fractions in the layer is justified by the wavy shape of the channels in which the fine fractions are located. However, this phenomenon can be justified by the forced migration of small particles inside the cavities of the layer under the influence of mobile gases. The influence of the mobility of particles during air blowing of separated and mixed granular layers on the coefficient of gas-dynamic resistance is investigated. A smooth decrease in the value of the coefficient with an increase in the air flow rate before the transition of the layer to the fluidization mode was observed for monofraction layers. Fractures, caused by the formation of a low-permeability area due to the placement of small fractions in narrow places between large ones, have been identified for the separated layers. The presence of such a fracture depends on the ratio of particle sizes and their roughness. The increase in pressure under the bed allows the fines to gradually move upward through the voids between the larger fractions. A layer of small balls formed on top and the pressure loss in the entire steel layer is about twice as high as for the separated layer. This is due to the fact that the small balls completely fill the voids between the large pellets and the total height of the column of balls in the channels of the layer has approximately doubled in relation to the initial filling height. In addition, the tortuosity of the channels between large pellets, through which air passes, increases, which contributes to an increase in the gas-dynamic resistance to the layer. An abrupt transition to a "fluidized" bed is observed for a monofractional charge of small balls at a critical gas pressure drop, pressure pulsations occur ±100 Pа and consumption ±0,365·10–3 m3/s. A spontaneous sharp drop in the drop occurs after the formation of geyser channels. The rigid structure of the layer, characteristic of the agglomeration process, ensures uniform movement of gases in the layer, but the valve effect occurs when the content of fine fractions in the layer is more than 3.1 % and increases the energy consumption for the movement of gases in the layer by 30 %. The placement of two or more particles in such cavities between large and retained in them due to friction forces occurs in this case. Elimination of the low-permeability barrier will increase the height of the dormant layer from 400 to 550–600 mm and reduce the consumption of solid fuel of the charge by 10–15 % due to its redistribution along the height.

Investigation of the flow structure in three-dimensional waves on falling liquid films using light field camera

Fluid velocity measurement in liquid films is a challenging task due to the small film thickness and large transverse gradients of velocity. While this problem was solved for the case of two-dimensional waves by several research groups, measurements in three-dimensional waves impose additional difficulties that we managed to overcome in the course of this study. We used a single light field camera for simultaneous particle tracking velocimetry and laser-induced fluorescence film thickness measurements. In this way, obtained velocity fields were related to the wavy interface shape. The applicability of the proposed methodology was demonstrated in the test experiments, which were carried out for two-dimensional regular waves. Measurements in three-dimensional waves were performed for the fluids with different viscosities and surface tensions but with close values of the Kapitsa number. In all investigated cases, the flow structure in different parts of waves is similar. Comparison of the experimentally obtained velocity fields with calculations by weighted residual integral boundary layer model shows qualitative agreement.

Unsteady simulation of flow and heat transfer in a transonic turbine stage under non-uniform inlet conditions

In modern aero-engines, the temperature non-uniformity (hot-streak) caused by the combustors and secondary flows caused by the rotor blades have a considerable impact on the aerothermal performances of the high pressure (HP) turbine. In this study, two idealized hot-streaks (radial and rounded) from literature and one engine representative hot-streak (distorted) were evaluated within a HP turbine stage using unsteady numerical simulation. The results were analyzed and discussed and they include, the stage performance, unsteady flow visualization, unsteady hot-streak transport, secondary flows/hot-streak interaction and blades thermal loading. It was found that the rotor passage had various complex secondary flows and the boundary layer on its surface undergone several transitions. The hot-streak transport and its contact with vane and rotor blades differed from one case to another. The secondary flows had a remarkable impact on the rotor exit temperature. They induced wavy shapes and corrugations of temperature gradients near the endwalls. All hot-streaks were completely deformed and distorted across the turbine stage. The rotor surfaces suffered from hot temperatures under radial and distorted hot-streaks compared with rounded hot-streak. Very high levels of the heat transfer were generated on the rotor suction side near the endwalls due to the vortices.

Dynamics and chatter stability of crest-cut end mills

Chatter is a major problem reducing part quality and productivity in milling operations. In order to improve productivity with standard end mills, higher cutting speeds must be employed to reach deeper stability lobes. However, due to machine tool and machinability limitations in cutting hard-to-cut materials, higher cutting speeds are not feasible. For those cases, special milling tools such as variable pitch and crest-cut cutters offer an alternative method to increase productivity. Due to their special geometry crest-cut tools introduce large stable regions at low-speed ranges where variable pitch tools provide narrow stability lobes. This advantage is caused by the wavy edge shape along the cutting edges of the crest-cut tools. In this study, stability of crest-cut tools is studied using the semi-discretization method by implementing a novel geometrical modeling approach enabling accurate cutting force predictions verified experimentally for the first time in literature. Based on the proposed model, the effect of edge wave geometry on stability is analyzed and compared with standard and variable pitch tools. Results show that the crest-cut tools introduce significant advantages in terms of stability limit and stable zones compared to other types of end mills. This superiority results in higher productivity as well as higher robustness at a different cutting speed zones. Finally, a guideline is presented for selection of the best crest-cut tool geometry for desired operating conditions.

Chiral Plasmonic Nanowaves by Tilted Assembly of Unidirectionally Aligned Block Copolymers with Buckling-Induced Microwrinkles.

Chiral-structured nanoscale materials exhibit chiroptical properties with preferential absorptions of circularly polarized light. The distinctive optical responses of chiral materials have great potential for advanced optical and biomedical applications. However, the fabrication of three-dimensional structures with mirrored nanoscale geometry is still challenging. This study introduces chiral plasmonic nanopatterns in wavy shapes based on the unidirectional alignment of block copolymer thin films and their tilted transfer, combined with buckling processes. The cylindrical nanodomains of polystyrene-block-poly(2-vinylpyridine) thin films were unidirectionally aligned over a large area by the shear-rolling process. The aligned block copolymer thin films were transferred onto uniaxially prestrained polydimethylsiloxane films at certain angles relative to the stretching directions. The strain was then released to induce buckling. The aligned nanopatterns across the axis of the formed microwrinkles were selectively infiltrated with gold ions. After reduction by plasma treatment, chiral plasmonic nanowave patterns were fabricated with the presence of mirror-reflected circular dichroism spectra. This fabrication method does not require any lithography processing or innately chiral biomaterials, which can be advantageous over other conventional fabrication methods for artificial nanoscale chiral materials.

Thermo-hydraulic performance and exergy analysis of a fin-and-tube heat exchanger with sinusoidal wavy winglet type vortex generators

The widely used fin-and-tube heat exchangers have a low air-side heat transfer capacity. Enhancing the air-side thermo-hydraulic performance is a key point of the relevant research. Vortex generators have been proven to be one of the most promising techniques to improve the air-side heat transfer capacity of the fin-and-tube heat exchangers. Herein, this paper proposed an original sinusoidal wavy winglet type vortex generator to achieve high heat transfer performance with moderate increased pressure drop penalty. A three-dimensional numerical simulation was conducted to explore the air-side thermo-hydraulic performance with Reynolds number ranging from 1027 to 2054. The longitudinal vortex is generated in the channel so as to enhance the intensify of convective heat transfer. Especially, the wave-shaped vortex generators can produce many local small-scale secondary flows. And it is confirmed that the frontal area of the vortex generator can be effectively extended by such wavy shape and a more intensified disturbance can be caused in the air-side. Furthermore, the effects of the attack angle (α), dimensionless height (Hp) and especially arrange position of the vortex generator were investigated. Additionally, the ranges of the Nusselt number ratio, friction factor ratio and surafece goodness factor in this study are 1.09–1.52, 1.09–2.31, and 1.06–1.24, respectively. Moreover, it is also very crucial to evalute the grade of energy and to explore the irreversible loss druing the heat tranfer process in view of the second law of thermodynamics. And the thermal dissipation can be reduced by up to 5.85% compared with the plain fins from the perspective of exergy analysis.

Preparation of Modified Fluorographene Oxide with Interlayer Supporting Structure.

Fluorinated graphene (FGi) is easy to agglomerate, after which it turns into a curly and wavy shape, which results in a great decrease in the properties of the resultant composite materials and coatings. In this study, fluorinated graphene oxide (FGO) modified with p-phenylenediamine (PPD) was prepared, but with a view to avoid its agglomeration and retain a sheet-like structure. Through the reaction between PPD and the epoxy groups of FGO, the modified FGO with an amino group (N-PGO) had a larger interlayer d-spacing than FGO. The stability of N-PGO was also improved, and nitrogen, fluorine, oxygen, and carbon were evenly distributed in the N-PGO sheets. All the results indicate that PPD can act as an effective spacer to separate graphene sheets for good anti-agglomeration properties. This method produced modified graphene with fluorine, amino, and carbonyl groups. It shows potential in introducing N-PGO as a reactive modifier in composite materials and coatings for a variety of industrial applications including waterborne epoxy materials.

FLOW FIELD PLATE DESIGN ANALYSIS WITH CROSS-SECTION WAVE RECTANGULAR SERPENTINE USING 3D FLOW SIMULATION ON PROTON EXCHANGE MEMBRANE FUEL CELL

The availability of petroleum which continues to decrease and the level of public consumption which is always increasing are serious problems today. Renewable energy needs to be researched on an ongoing basis to anticipate the availability problems above. Proton Exchange Membrane Fuel Cell (PEMFC) is an environmentally friendly source of electrical energy because it only requires hydrogen and oxygen as raw materials and water as a result of the reaction. This study will discuss the PEMFC flow field plate because this component dominates the weight and cost of manufacture. Research on flow field plate PEMFC with wave rectangular cross-section is necessary to develop the PEMFC concept with better performance results. This study aims to determine the effect of the wavy cross-section shape on the distribution of channel average speed, channel outlet speed, inlet pressure, channel average pressure, and channel outlet pressure. This study uses a computational fluid dynamic (CFD) method using SolidWorks flow simulation software. This study provides an overview of the serpentine type of flow field plate with a wave rectangular and rectangular cross-section. The wave rectangular cross-section has a higher average velocity, outlet velocity, inlet pressure, and pressure than the rectangular cross-section. This is what will make PEMFC performance higher. The wave rectangular cross-section has nearly the same number of outlet pressures as the rectangular cross-section. Possible development of this research is the creation of simulation software to calculate other parameters that affect PEMFC performance.

Double rotations between an inner wavy shape and a hexagonal-shaped cavity suspended by NEPCM using a time-fractional derivative of the ISPH method

A transient two-dimensional ISPH method based on the time-fractional derivative was applied for emulating thermosolutal convection of the nano-encapsulated phase change material (NEPCM) embedded in an annulus between an inner wavy shape and outer hexagonal-shaped cavity. The impacts of a magnetic field and double rotations amongst an inner wavy shape and outer hexagonal-shaped cavity on the heat and mass transmission of NEPCM in an annulus have been conducted. Effects of a time parameter τ (0.01 − 1), frequency parameter ω (1 − 7), fractional time derivative α (0.95 − 1), Darcy parameter Da (10−2 − 10−4), Hartmann number Ha (0 − 100), fusion temperature θf (0.05 − 0.8), and Rayleigh number Ra (103 − 105) on the contours of temperature, heat capacity, concentration, and velocity field as well as profiles of Nu¯ and Sh¯ are investigated. The main findings signaled that the double rotations plays effectively in speed up the nanofluid movements, and changing the features of temperature, concentration, and heat capacity inside an annulus. An augmentation in a frequency parameter boosts the nanofluid speed by 128.57%. A decline in α from 1 to 0.95 enhances the maximum nanofluid velocity by 13.73%. The nanofluid movements within an annulus are reduced according to an increase in Ha and a decrease in Da. The power in the Rayleigh number enhances the nanofluid movements within an annulus.

Printed Stretchable Single-Nanofiber Interconnections for Individually-Addressable Highly-Integrated Transparent Stretchable Field Effect Transistor Array.

Stretchable electronics have been spotlighted as promising next-generation electronics. In order to drive a specific unit device in an integrated stretchable device, the interconnection of the device should be placed in a desired position and addressed individually. In addition, practical stretchable interconnection requires reliable stretchability, high conductivity, optical transparency, high resolution, and fast and large-scale production. This study proposes an approach to meet these requirements. We print the single wavy polymer nanofibers (NFs) in a desired position and convert them into metal NF interconnections. The nanoscale diameter and the wavy cylindrical shape of the metal NFs are the main reasons for the reliable stretchability and the excellent transparency. Using the stretchable metal NFs and the stretchable organic semiconductor NFs, an array of all-stretchable transparent NF-field effect transistors (NF-FETs) is demonstrated. The highly integrated NF-FET array (10 FETs/mm2) shows uniform performance and good stability under repeated severe mechanical deformations.

Tortuosity in tumours: The need of combining multi-phase flows with machine learning tools

This article presents a preliminary approximation of the effect in blood flow produced by tortuosity in the blood vessels. This roughness is related to certain diseases (such as tumours) and the modelling of the flow properties can help to characterize the existence of such diseases. Malignancy provokes local changes to vessel shape and characteristic vessel tortuosity appears early during tumour development. Numerical simulations have been carried out, where the elastic behaviour modelling the surface of blood vessels has been represented using several geometries with different wavy shapes. The complexity of the topology patterns, which could be related with the different particle paths found in different geometries, encourages to continue this research using novel machine learning tools to predict and connect the main flow instabilities with the tumour evolution.

Improvement of a Tunable Stiffness Organ-Grasping Device by Design of a Wavy-Shaped Beam Structure

Tunable stiffness mechanisms can increase the noninvasiveness and stability of organ manipulation in laparoscopic liver resection. We have developed an organ-grasping device using beam-shaped tunable stiffness mechanism. Increasing the change ratio of stiffness will improve the performance of the device by offering high flexibility when adhering to the liver surface and high rigidity during the manipulation of the liver; however, optimal design of the beam has not been investigated. In this study, we investigate the wavy structure shape of the device that enhances the change in the ratio of stiffness. To increase the stiffness in a high-stiffness state, we used principal stress lines in the device to design the edge curve of the wavy shape material in the beams. We also investigated the arrangement of the wavy shape to decrease the stiffness in a low-stiffness state. Simulation using finite element method showed that the change ratio of stiffness was improved up to 13.0 by the new wavy shape arranged with the uniformly thick bottom of the waves.

Numerical Investigation on the Dynamic Flow Pattern in a New Wastewater Treatment System

Currently, industries seek to optimize the development of technology from energy-saving, economic, and environmental perspectives. Dissolved air flotation (DAF) is one of the most effective wastewater treatment systems. However, it requires considerable energy and causes significant operating costs. A recently emerged application of using fluidic oscillators (FOs) to generate microbubbles has attracted extensive attention, as it consumes much less energy and has proven to be a more energy-efficient technique. In this article, a microbubble generator based on FOs is introduced into the flotation tank, and an energy-saving water treatment system, namely fluidic air flotation (FAF), is presented. Using the computational fluid dynamics (CFD) method, the flow pattern of the FAF is investigated. It is observed that FAF generates a dynamic flow pattern, which is beneficial for bubble removal. At the upper part of the separation zone, the flow pattern exhibits a wavy shape. The flow pattern at the lower part switches between clockwise and counterclockwise. The air distribution of the separation zone is also studied. It is found that the height of the “white water” zone almost linearly decreases with the increase in bubble diameter and diffuser size. FAF consumes almost no energy and occupies a small area, and it is expected to provide a promising solution to develop a new generation of the wastewater treatment system.

Effect of viscoelastic properties of polymer and wavy shape of the CNTs on the vibrational behaviors of CNT/glass fiber/polymer plates

Carbon nanotube (CNT)-reinforced polymer nanocomposites possess marvelous stiffness and strength as well as viscoelastic nature due to the time-dependent properties of the polymers. Hence, adequate knowledge about their rheological behavior is required if it is aimed at using such nanomaterials in design of aerospace structures. Present manuscript is arranged to account for the time-dependency of the polymer as well as wavy shape of the CNTs while tracking the vibrational responses of multi-scale hybrid nanocomposites for the first time. To this purpose, a mixture of the modified Halpin–Tsai model and mixture’s rule is used for the homogenization process. According to the dynamic form of the virtual work’s principle, the governing equations of the problem will be attained based on a higher-order shear deformable plate theorem to consider for thick structures. In addition, the Navier’s analytical solution is implemented to extract the system’s natural frequency for simply-supported plates. The findings of this paper indicate on the fact that the vibration suppression in the nanocomposite structures can be delayed if a high value is assigned to the characteristic relaxation time of the polymer. Besides, it is illustrated that hybrid nanocomposites consisted of wavy CNTs (i.e., corresponding with more realistic case) cannot provide ideal frequencies related to the nanocomposites manufactured from straight CNTs.

In situ transmission electron microscopy studies of 30 keV H2+ and He+ dual-beam irradiated Pd: defect generation and microstructural evolution under varied temperatures and foil thicknesses

To fully understand the tritium aging behavior of palladium (Pd), an important material applied in hydrogen isotope storage and tritium engineering, an in situ irradiation of 30 keV H2+ and He+ dual beam was performed for the investigation of the microstructural evolution in Pd. The irradiation dose, temperature, and sample thickness obviously affected the morphology, distribution characteristics, density, and size of dislocation loops, bubbles, and bubble-loop complexes. Highly dense loops were aggregating at lowered temperatures, whereas the loop density dropped dramatically, producing bubble-loop complexes at elevated temperatures. Most of loops were 1/3<111> Frank loops with quasi-circular under a low dose at 573 K and then transformed to 1/2<110> perfect loops with wavy and polygonal shape at a high dose. The difference in growth behavior between faulted and perfect loops suggested that there was a critical transform loop size ~32 nm in diameter. The heterogeneity in size and shape of bubbles could be attributed to the interaction between bubbles and the periphery loop. Moreover, the hydrogen resulted in the formation of larger bubbles when compared with the single-beam helium irradiation. The unfaulting transition of loops led to bubble redistribution. The corresponding mechanisms of in situ irradiation experimental results were discussed.