Applications in engineering science最新文献

Cellular lightweight concrete (CLC) block masonry is an eco-friendly building material gaining popularity in both developed and developing countries. Despite its increasing use, the material's behavior under seismic loading remains insufficiently understood. This research involved quasi-static testing of two full-scale CLC blocks masonry walls strengthened with ferrocement overlay. One of the strengthened walls was subjected to confinement, while the other was unconfined. The aim was to assess their seismic performance by comparing force deformation curves, damping, stiffness degradation, and structural performance levels with non-strengthened walls. The findings indicate that the strengthened masonry outperformed the unreinforced version, suggesting that CLC block masonry exhibits potential for effective performance in low to moderate seismic zones.

The investigation of the physical processes determining the melting of the lithospheric rocks is of crucial importance for understanding the volcanic dynamics and its related consequences. Rock melting begins when a sufficiently high temperature is experienced by the rock solidus. The heat transfer from the asthenosphere to the lithosphere can be assumed as the main mechanism accountable for the partial melting of rocks, and initiating magma generation. The heat transfer to the lithosphere is considered to be governed mainly by the convective motion inside the asthenosphere. In order to mathematically describe this process, a generalization of a nonlinear convective 1D model, possibly representing a useful though simplified model for the birth of a volcano, and already analyzed from an analytical viewpoint (Godano et al., 2022), is investigated; here, we solve numerically some physically meaningful initial and boundary value problems, and discuss the results.

Concrete is a widely used construction product. This product is presently concerned with the depleting nature of natural sand. Concrete is also being considered with supplementary materials to enhance its footprints. Hence, this study's goal is to examine the performance of reinforced concrete (RC) beams consisting of sustainable materials. The study seeks to qualify the use of concrete made using Sugarcane Bagasse Ash (SCBA) and Recycled Polyethylene Terephthalate (RPET) as structural elements. Proportionately, 10 % RPET is used to partially substitute sand, and 5 % SCBA is used to partially substitute cement. The innovation of this study is in the dual substitution approach and structural behaviour examination. The research probes how RPET and SCBA affect the RC beams’ flexural and shear capacities. The tests are completed ensuing 28 days of water curing. Three RC beams are made for each of the conventional concrete and SCBA-RPET concrete. A set of beams is made for the shear capacity test, while another set is made to examine flexural capacity. The beam dimensions are 160 × 200 × 1200mm³. The findings inform that the beams made with 5 % SCBA and 10 % RPET have a flexural capacity of 11 % less than the conventional beams'. However, the SCBA-RPET beams revealed a shear capacity that is 17.38 % more than the conventional beams'. The crack patterns during and after the shear and flexural strength tests are similar and comparable for the SCBA-RPET beams and the conventional beams. Thus, a sustainable concrete mix suitable for use as a structural beam is derived.

The paper presents finite element (FE) simulations of an unstiffened plate specimen punched by a rigid indenter, to study their fracture behaviors and energy dissipation mechanisms. Load-displacement curves from the numerical results are presented for various indenter radii i.e., 35, 50, 65, 80, and 95 mm. Moreover, the outcomes of this investigation should have relevance to estimating grounding scenarios in which the bottom sustains local penetration. The numerical analysis includes the benchmarking study that is based on experimental data to ensure that the current result has satisfactory accuracy. It is concluded that the indenter radii play an important role in the crushing resistance of the plate, especially having a significant influence on the maximum force. Compared with the 35 mm cone radii, the maximum force measured in the tests increased by 110.97 % in the 95 mm indenter radius. Furthermore, the energy absorption produced by the 95 mm cone radius has a higher value at 32.23 kJ compared to 10.1 kJ, which was obtained from a 35 mm cone radius. Discussions on the effects of indenter velocities are also included in this study.

It is evident how corrosion flaws affect the tension and strain of pipelines that pass oblique-slip faults. The pipeline is very risky and is more likely to experience tensile and buckling damage when corrosion develops in the major deformation region of the pipeline. This will also significantly diminish the pipeline's failure slippage. This research uses a three-dimensional finite element modeling of trans-fault pipes to study the mechanical reaction and influencing factors of corroded pipelines under the action of oblique-slip faults. It is determined that the distribution of stress and strain as well as the pipeline's extension trend are changed when corrosion faults are present. The concentration of tensile and compressive strain along the corroded circular cross-section at the time of damage, followed by a gradual expansion through the entire corroded circumferential cross-section, and the pipeline's extrusion, folding, and bulging, are the manifestations of the influence of corrosion defects on the pipeline at damage. Tensile and compressive strains in the pipeline increase, failure slippage is reduced, and the pipeline experiences tensile damage and corrosion. The length of the pipeline corroded in the circumferential direction, the length of the corroded length in the direction of corrosion along the pipeline axis, and the corrosion depth increase all contribute to these outcomes. The location of corrosion defects has the greatest influence on the dynamics of the pipeline and is most dangerous in the large deformation section from -10 m to 10 m; the corrosion effect is very small when the corrosion is located on the right side of the fracture surface at 25 m. The risk of buckling damage is higher in this scenario, where the corrosion depth has the greatest effect. The conclusions of this paper can be used as a reference for the seismic and corrosion-resistant design of cross-fault pipelines.

One of the main factors influencing the quality of production shape and energy consumption in an extrusion process is the interaction between the material and the wall. To investigate the tribological behavior of extrudable kaolin and a rigid wall, a tribometer is specifically designed and validated for measuring friction at the kaolin-wall interface. Compared to another tribometer in the literature, this device permits the variation of the normal stresses at the wall/material interface during testing. Finally, the tribological behavior of kaolin friction is determined within a range of velocities from 10⁻3 m/s to 5.10⁻² m/s and a range of normal stress from 120 to 250 kPa.

This work studies the mechanics of novel origami solar modules with tensegrity architecture for integration in the dynamic solar façades of energy-efficient buildings. The analyzed modules are deployed by adjusting the rest lengths of cables attached to given nodes, so as to form a tensegrity origami. Their stiffness is tuned by adjusting the pretension of the actuation cables, when the deployment motion is locked. The insertion of solar thermal or photovoltaic panels into the rigid elements of the module makes it possible to form positive-energy solar systems. The work studies the kinematics and the mechanics of the investigated structures through analytic and numerical methods. Two folding motions are examined: to open and close the modules and to track sun rays. The rapid prototyping of a physical mock-up permits an experimental validation of the force–displacement response in a given configuration of the sun-tracking motion. A procedure for the computation of the fundamental vibration modes and vibration frequencies of a quadrangular solar module is also given, and the expected response of the system under wind loading is outlined.

Recent advancements in thermal engineering have led to the development of stable thermal properties and practical applications for nanofluid flow. Consequently, this study aims to explore the heat and mass transfer characteristics of a non-Newtonian Maxwell nanofluid when it comes into contact with a stretched surface containing porous features that allow for fluid suction velocity. Additionally, the research takes into account how the Soret and Dufour effects impact the processes of heat and mass transfer. A less-explored aspect of research in this field relates to the velocity slip boundary conditions when nanofluids with changing viscosity are involved. Additionally, the model employed in this study illustrates the influence of both viscous dissipation and variable thermal conductivity on the processes of heat and mass transfer. The mathematical flow model is described by nonlinear partial differential equations, which are subsequently transformed into non-dimensional ordinary differential equations. The resulting system is then solved numerically using the shooting method. This study visually examines the impact of physical variables on temperature, flow characteristics, and concentration patterns. Furthermore, it provides graphical representations of estimated values for the skin friction coefficient, Sherwood numbers, and local Nusselt numbers, which are also organized in tables for analysis. In conclusion, by comparing our data with previous results, we confirm the accuracy and reliability of the proposed method. A significant discovery is that the nanofluid velocity decreases as the Maxwell, porous, and slip velocity parameters are increased. Furthermore, the nanofluid concentration rises when the thermophoresis and viscosity parameters increase.

In this paper, we introduce a methodology to design genuinely two-dimensional (2D) second-order well-balanced path-conservative central-upwind (PCCU) schemes. The scheme studies dam-break with high sediment concentration over abrupt moving topography quickly spatially variable even in the presence of the resonance. This study is possible via a 2D hyperbolic sediment transport model (including arbitrarily sloping sediment beds and associated energy and entropy) in new generalized Shallow Water equations derived with associated energy and entropy in this work. We expose some properties of the model and we establish an existence result of global weak solutions. In addition, we show the convergence of a sequence of solutions of the proposed new model. The second-order accuracy of the PCCU scheme is achieved using a new extension AENO (Averaging Essentially Non-Oscillatory) reconstruction developed in the 2D version of this work. We prove that the derived 2D scheme is well-balanced, positivity-preserving and steady states capturing. Several dam break tests are made to show the ability and the superb performances of the proposed numerical modeling. The proposed method can help to address many engineering problems.

In recent decades, the phase field method has been widely used in order to model and simulate the damage in various materials and/ or structures. In this simulation method, the regularization length is an important parameter to describe the width of the smeared crack and reflect the crack as a sharp discontinuity. The regularization parameter depends on the material properties thus its value must be small enough. This leads to the element mesh size being small, in other words, the number of elements increases, causing computation costs to much increase. On the other hand, in brittle materials, the positive and negative parts of the strain tensor represent the tension and compression behaviours in the materials. Two parts of the strain tensor must satisfy strain orthogonal decompositions in the context of the elastic stiffness tensor behaving as a metric. Therefore, in this work, the phase field method is incorporated into the improved degradation functions and strain orthogonal condition in order to investigate the crack nucleation and propagation as well as predict the peak load and/ or the critical stress corresponding to the first crack onset appeared in the experimental brittle material such as plaster. A comparison between the obtained results and results of the available experimental tests and/ or relevant simulation methods will demonstrate that the present proposed method makes the mesh size coarser thus the computational cost is significantly reduced without changing the crack path. Moreover, the present simulation method helps to raise the accuracy of the global and local mechanical responses in the material, which is represented by smoother relationship curves.