Uniform Load Research Articles

PH-Responsive Modified HAMA Microspheres Regulate the Inflammatory Microenvironment of Intervertebral Discs.

Currently, intervertebral disc (IVD) degeneration is believed to lead to local accumulation of lactic acid in the IVD, a decrease in pH, activation of the inflammatory pathway, and continued destruction of homeostasis of the IVD. To address these issues, the intelligent and accurate release of drugs is particularly important. In this study, acid-sensitive release methacrylated hyaluronic acid (HAMA) microspheres were constructed by using microfluidic technology, which can be used as a targeted drug delivery system for intervertebral disc degeneration (IVDD) through Schiff base chemical bonding on the surface of the microspheres to achieve intelligent drug release. Interleukin-1 receptor antagonist (IL-1 Ra) is a naturally occurring anti-inflammatory antagonist of the interleukin-1 family of pro-inflammatory cytokines. Despite its outstanding broad-spectrum anti-inflammatory effects, IL-1 Ra has a short biological half-life (4-6 h). The slow-release performance of IL-1 Ra can be greatly improved using bovine serum albumin nanoparticles (BNP). In addition, the modified HAMA microspheres exhibited good injectability and porosity, and efficient and uniform loading of nanoparticles was achieved via the Schiff base bond. The inflammatory microenvironment can be significantly reversed by transporting the modified HAMA microspheres-BNPs (Modified MS) to the degenerative nucleus pulposus.

A Case Study on Using the Concrete Cover Block in Steel Reinforcement Bar: Ghorahi Dang, Nepal

Cover block is one of the basic component on building structure like slab, column, beam, foundation. It is a multi- functionary engineering material. In maximum construction sites, bricks, stones, steel bars are used instead of cover block. This brings a lots of depraved consequences on building structures like lack of well spacing between surface and reinforcement bars, unbalance position of steel bars, reduce the lifespan of building and corrosion. Here, the main function of cover block is to reinforce the building structure by avoiding the corrosion on steel bar or avoiding the moisture with the steel bar, providing the resistive property, distributing an uniform load and managing space. In this way, the cover block is attached in a reinforcement bar in order to reinforce a building structure. When cover block was applied in a building structure, it made a building more durable as well as more attractive by maintaining the shape. This observation suggests that the use of cover block can contribute in strengthening a building structure and maintaining a position and space of a reinforcement bars as well as a structure. Key Words: Concrete cover block, Reinforcement bar, Potential failure of structure, Space maintaining, Corrosion activity.

A Universal Target Plate Design Scheme for Stellarators: theoretical basis and its application to heat load control

Abstract This study introduces a novel divertor target design scheme for stellarators, grounded in mathematical treatments and tailored to control toroidal heat load distributions. Initially, a differential equation characterizing toroidally uniform heat load distribution has been established in a two-dimensional (2D) slab configuration, and its analytic solution has been obtained. Subsequently, a numerical scheme has been developed to adapt the analytic solution into the 3D surface shape of stellarator target. The effectiveness of this design scheme has been validated through simulations of the Chinese First Quasi-axisymmetric Stellarator (CFQS) using a suite of codes including HINT, FLARE and EMC3-EIRENE, where a toroidally uniform heat load distribution has been achieved with an island configuration. Further, the effects of input parameters on the target shape and heat load distribution have been studied. The robustness of the designed target has been investigated by simulation results with varying magnetic island configurations, confirming that the toroidal uniformity of heat load distribution is insensitive to changes in island configurations. Moreover, the designed target has been assessed with gas puffing of neon, which shows that neon injections effectively reduce the heat loads without altering the toroidal uniformity of heat load distributions. The proposed scheme highlights the importance of theoretical and mathematical foundations of target design, offering an advantageous alternative/complement to the traditional numerical schemes.

Combination of Hollow Capsule Structure and Zn Uniform Load for the Conversion of Methanol to Aromatics over Zn/ZSM-5 Zeolites.

As an important nonoil route for acquiring aromatics, the highly efficient conversion of methanol to aromatics over Zn/ZSM-5 zeolites remains an ongoing challenge. In this work, we developed a uniform loading approach of zinc and further combined it with a hollow capsule structure to design the high-performance Zn/ZSM-5 catalyst. The electrostatic assembly among EDTA3-, n-butylamine+ and negative silica-alumina gel gave rise to an "Inorganic-Organic Hybrid Sphere" in form of Na(l+m+n+3x)-(y+z)·{[(SiO)4Al-]l/(SiO-)m(n-butylamine+)y(EDTA3-)x(n-butylamine+)z(SiO-)n, which further transformed into mesoporous aluminosilicates sphere (MASS) through calcination. The characteristic of abundant mesopore guaranteed MASS fantastic ability to evenly incorporate Zn ingredient inside, and the resultant Zn/MASS further served as a "hard template" for the direct synthesis of Hollow Zn/ZSM-5 capsules, rather than after impregnation. When tested in the methanol-to-aromatics (MTA) process, the direct synthesis method not only facilitated the homogeneous dispersion of the Zn ingredient, but also benefited for the generation of more (ZnOH)+ sites and strengthened their synergism with zeolite acid for the superior aromatics selectivity (50.63%). Meanwhile, the hollow capsule structure increased the contact time of MTA intermediate products with the Zn/ZSM-5 shell, and it increased the coke-admitting capacity and suppressed the coke rate, which maintained quite an excellent stability (131 h). Therefore, the above combination of hollow capsule structure and uniform load of Zn ingredient brings forward a wide prospect to develop zeolite materials with excellent properties in catalysis.

Deviatoric couple stress theory and its application to simple shear and pure bending problems

Classical couple stress theory is indeterminate since the number of independent basic equations is inconsistent with that of field variables and the corresponding differential equation is not closed. The purpose of this paper is to remedy this gap and it is proven that the spherical part of the couple stress tensor vanishes. With the vanishing trace of the couple stress tensor as a premise or the couple stress tensor being deviatoric (or traceless), a deviatoric couple stress theory is named and proposed. Besides basic equations, the governing equation along with appropriate boundary conditions are given for a three-dimensional problem. Two special cases of plane problems and anti-plane problems are also provided. A simple shear problem is considered to show the advantage of the DCST. An elastic layer with a clamped surface under uniform shear loading on the other surface is solved. Exact solution of the in-plane and anti-plane shear problems of an elastic strip is determined and however, it has no solution if classical elasticity is used. The results indicate that there exists a boundary layer near the clamped surface of the strip or a great stress gradient occurs near the clamped surface when the characteristic length is sufficiently small. An annulus subjected to anti-plane shear loading on the inner edge and fixed on the outer edge and the pure bending of a 3D bar with rectangular cross-section are analyzed to illustrate the size-dependent effect. Modified couple stress theory and consistent couple stress theory can be reduced as two extreme cases of the present theory.

Enhancing Chemoimmunotherapy for Colorectal Cancer with Paclitaxel and Alantolactone via CD44-Targeted Nanoparticles: A STAT3 Signaling Pathway Modulation Approach

Chemoimmunotherapy has the potential to enhance chemotherapy and modulate the immunosuppressive tumor microenvironment by activating immunogenic cell death (ICD), making it a promising strategy for clinical application. Alantolactone (A) was found to augment the anticancer efficacy of paclitaxel (P) at a molar ratio of 1:0.5 (P:A) through induction of more potent ICD via modulation of STAT3 signaling pathways. Nano drug delivery systems can synergistically combine natural drugs with conventional chemotherapeutic agents, thereby enhancing multi-drug chemoimmunotherapy. To improve tumor targeting ability and bioavailability of hydrophobic drugs, an amphiphilic prodrug conjugate (HA-PTX) was chemically modified with paclitaxel (PTX) and hyaluronic acid (HA) as a backbone. Based on this concept, CD44-targeted nanodrugs (A@HAP NPs) were developed for co-delivery of A and P in colorectal cancer treatment, aiming to achieve synergistic toxicity-based chemo-immunotherapy. The uniform size and high drug loading capacity of A@HAP NPs facilitated their accumulation within tumors through enhanced permeability and retention effect as well as HA-mediated targeting, providing a solid foundation for subsequent synergistic therapy and immunoregulation. In vitro and in vivo studies demonstrated that A@HAP NPs exhibited potent cytotoxicity against tumor cells while also remodeling the immune-suppressive tumor microenvironment by promoting antigen presentation and inducing dendritic cell maturation, thus offering a novel approach for colorectal cancer chemoimmunotherapy.

Incorporation of Mo2C nanoparticles to pollen-derived 3D porous carbon as electrocatalyst for high performance lithium-sulfur batteries

The practical application and development of lithium‑sulfur (LiS) batteries are limited by the slow redox reaction kinetics and shuttle effect of polysulfide lithium (LiPSs). To address these issues, three-dimensional porous carbon (PC, derived from rapeseed pollen) modified with molybdenum carbide (Mo2C) nanoparticles is prepared by a simple and environment-friendly method. On the one hand, the PC-Mo2C host material can facilitate the uniform loading of sulfur and reduce its volume expansion due to its porous carbon structure. On the other hand, it mitigates the shuttle effect by effective chemical adsorption of LiPSs to form strong physical confinement and catalyze the conversion of LiPSs via the aid of the decorated Mo2C nanoparticles. Density functional theoretical calculations also illustrate the Mo2C nanoparticles are capable of inhibiting the shuttle of LiPSs and further improving the cycling stability. The results show that the PC-Mo2C/S electrode exhibits excellent electrochemical performance with high cycle stability (fading rate of 0.066 % per cycle at 0.2C and 0.054 % per cycle at 1C) and outstanding rate capacity (623.2 mAh g−1 at 5C).

Elastic Fields Around Multiple Stiff Prestressed Arcs Located on a Circle

Abstract The plane strain problem of an isotropic elastic matrix subjected to uniform far-field load and containing multiple stiff prestressed arcs located on the same circle is considered. The boundary conditions for the arcs are described by those of either Gurtin–Murdoch or Steigmann–Ogden theories in which the arcs are endowed with their own elastic energies. The material parameters for each arc can in general be different. The problem is reduced to the system of real variables hypersingular boundary integral equations in terms of two scalar unknowns expressed via the components of the stress tensors of the arcs. The unknowns are approximated by the series of trigonometric functions that are multiplied by the square root weight functions to allow for automatic incorporation of the tip conditions. The coefficients in series are found from the system of linear algebraic equations that are solved using the collocation method. The expressions for the stress intensity factors are derived and numerical examples are presented to illustrate the influence of governing dimensionless parameters.

Performance of photovoltaic panels with different inclinations under uniform thermal loading

Integrating photovoltaic (PV) panels with different tilt angles in building envelopes or roofs is widely employed for environmental sustainability. However, little is known about the influence of different tilt angles on the thermal failure of the photovoltaic façades or roofs in fire conditions. A total of 15 four-edge shielded PV panels (300 × 300 × 4.7 mm3), with five different inclinations of 0°, 15°, 30°, 45° and 60°, were heated to fail using a uniform radiant panel. Measurements were taken to track glass thermal breakage, surface temperatures, incident heat flux and failure characteristics. The glass fracture and pyrolysis of the internal thermoplastic materials were observed under thermal radiation. The average breakage time of glass in PV panels showed an increasing trend with increasing inclination of the PV panels. Moreover, when the PV panels were tilted beyond 30°, the time to failure increased more significantly. The maximum temperature difference and heat flux that the PV panels can withstand were primarily measured within the range of 61–84 °C and 8–15 kW/m2, respectively. Finally, the test results were simulated by a finite element method (FEM) model, calculating the heat transfer and thermal stress of PV panels: the average errors concerning temperature distributions and failure times were smaller than 15 % compared with the experimental results.

Self-supported electrochemical sensor based on uniform palladium nanoparticles functionalized porous graphene film for monitoring H2O2 released from living cells.

Graphene film has been considered a promising material for the construction of self-supported electrodes due to its favorable flexibility and high conductivity. However, the film fabricated from pristine graphene or conventional graphene sheet reduced graphene oxide processes limited electrocatalytic performance. Decorating active metal species or incorporating heteroatoms intothegraphene framework have been proved to be effective methods to enhance the electrocatalytic efficiency of graphene film-based self-supported electrodes. Herein, we present a freestanding electrode composed of uniform Pd nanoparticles decorating N,S co-doped porous graphene film (Pd/NSPGF) and explore its practical application in differentiating various human colon cell types by in situ tracking the amount of H2O2 secreted from live cells. Our findings reveal that, on the one hand, the NSPGF has abundant surface and inner pores, which promote active site exposure, and mass diffusion during electrochemical reactions; on the other hand, the substitutional doping ofthe graphene framework with heteroatoms (e.g., N or S) can tailor its electronic and chemical properties, and facilitate the uniform loading of high-density Pd nanoparticles. Moreover, the intrinsic activity of Pd/NSPGF is regulated by the interaction of Pd nanoparticles withtheNSPGF support. Taking the advantages of morphology and composition, the self-supported Pd/NSPGF electrode displays remarkable electrochemical performance with a wide linear range up to 2.0mM, low detection limit of 0.1μM (S/N = 3), high sensitivity of 665 µA cm-2mM-1, and good selectivity. When applied in real-time trackingofthe H2O2 released from normal human colon epithelial cells and human colorectal cancer cells, the Pd/NSPGF-based electrochemical sensing system can distinguish the cell types by testing the number of extracellular H2O2 molecules released per cell, which holds considerable potential for early detection and monitoring of disease-related clinical specimens.

First Principles Variational Formulation and Analytical Solutions for Third Order Shear Deformable Beams with Simple Supports using Fourier Series Method

The Fourier series method for solving bending problems of third-order shear deformable beams (TSBD) is presented in this paper. The theory accounts for transverse shear deformation and is suitable for moderately thick beams. Transverse shear stress-free conditions are valid at the beam surfaces for TSDB. The field equations are two coupled ordinary differential equations in terms of two unknown displacement functions – transverse deflection w(x) and warping function For simply supported ends considered, the loading and unknown functions w(x) and are represented in Fourier series that satisfies the boundary conditions. The problem is reduced to a system of algebraic equations in terms of the Fourier coefficients wn and which is solved to obtain wn and Axial and transverse displacements fields, axial bending stress and transverse shear stress are then determined for the cases of point load at midspan, uniformly and linearly distributed loads over the span. The results are identical with previous results obtained by other scholars who used Ritz variational methods and other mathematical tools. For moderately thick beams under uniform load with l/h = 4, the results obtained for is 0.516% greater than the exact result by Timoshenko and Goodier while for thick beams under uniform load with l/h = 2, the result for is 1.96% greater than the exact result by Timoshenko and Goodier. Similar acceptable variation was obtained for for beams under linearly distributed load with the variations being less than 2% for l/h = 2. However, unacceptable variations of 68.37% were found for in thick beams under point load, for l/h = 2.0. The variation for however reduced to 12.513% for moderately thick beams under point load for l/h =4.

АНАЛІЗ ВПЛИВУ ІНДИВІДУАЛЬНИХ ХАРАКТЕРИСТИК КОМІРОК LiFePO4 НА ПАРАМЕТРИ РОБОТИ АКУМУЛЯТОРНИХ ЗБІРОК

The article analyzes the influence of the individual characteristics of lithium-iron-phosphate (LiFePO4) cells on the overall efficiency, stability and duration of operation of battery assemblies. The influence of such parameters as internal resistance, polarization resistance and capacity on the operation of battery assemblies under different load regimes and changes in temperature conditions was studied. It was found that these parameters can vary significantly between cells within the same assembly, which leads to an imbalance during the operation of the battery system. Such an imbalance causes an uneven distribution of charge between the cells, which reduces the overall performance of the system, accelerates the degradation of the cells and shortens their service life. To overcome these problems, the use of active balancing methods based on Unscented Kalman Filter (UKF) algorithms was proposed. The application of UKF allows for dynamic evaluation of the state of charge (SOC) of each cell and adjustment of system parameters in real time, which provides more accurate management of battery assemblies in conditions of variable external factors such as temperature and current loads. Special attention is paid to online identification of battery parameters, such as polarization resistance and capacity, which change over time due to cell aging. The conducted studies confirmed that constant monitoring of temperature regimes is critically important for maintaining stable operation of battery cells, preventing overheating and ensuring uniform load distribution. The performed simulation confirmed the effectiveness of the application of adaptive methods of balancing and temperature control, which allows to increase the reliability and overall performance of battery assemblies.

A size‐dependent model of strain gradient elastic laminated micro‐beams with a weak adhesive layer

AbstractA size‐dependent model for a laminated micro‐beam with a soft adhesive is developed in the framework of strain gradient elasticity theory. The layered beam is constituted by two Euler–Bernoulli strain gradient elastic isotropic beams, joined through a strain gradient spring‐type contact law at the adhesive level. The governing bending and extensional equations and boundary conditions are obtained by using the variational principle. The differential system shows a coupling between the flexural and axial behaviors of the upper and lower beams, due to the presence of interface terms related to shear and peeling stresses. Two benchmark problems have been presented through their closed‐form solutions, namely a simply‐supported laminated beam subjected to a uniform distributed load and a mode 2‐type loading configuration of a layered axially deformable beam. Size effects and non‐local phenomena, due to high strain concentrations, are highlighted. Though simple in their features, the examples prove the efficiency of the proposed approach in designing micro‐scale layered beams.

Research into multi-directional high stability techniques in the same plane for satellite static testing

In order to ensure the structural strength reliability of spacecraft base plate during launch and operation, it is necessary to perform the structural strength test of load synchronous loading on the base plate in the same plane to evaluate its structural bearing capacity under certain axial and shear loads. In order to meet the test requirements and simulate the real stress condition of the base plate, a reliable implementation scheme is proposed in this paper. Multi-directional uniform loading of a satellite base plate is completed by using the same plane multi-directional high stability test technology. The mechanical test of a satellite using this technology shows that the test strain is consistent with the theoretical simulation deformation. This technology effectively solves the problem of uniform loading in the same plane of the satellite base plate in mechanical testing.

Analyzing flexoelectric polarization of suspended membrane by nonlinear bending theory of plate

Strain gradient breaks inversion symmetry and induces flexoelectric polarization as well as electromechanical coupling in all material systems, though the effect is usually only significant at the nanoscale. Two-dimensional (2D) materials and thin membranes thus provide an ideal platform to explore flexoelectricity, which has been widely pursued, yet quantitative theoretical analysis is needed to guide the rapid experimental developments. In this work, we develop 2D flexoelectric model for suspended membrane based on von Kármán plate theory, and implement it into finite element computation using conforming BCIZ element. Numerical results and discussions on flexoelectric polarization in suspended membrane under uniform pressure or concentrated load are presented, which are validated by piezoresponse force microscopy (PFM) experiments under a range of membrane thicknesses and loading forces showing good agreement with computations. Since large strain gradient often exists in samples with small size in one or two dimensions, the method we develop provides a powerful tool to study a wide range of low-dimensional materials and structures with flexoelectric effect.

Mechanical analysis of modified femoral neck system in the treatment of osteoporotic femoral neck fractures

BackgroundDespite the explicit biomechanical advantages associated with FNS, it is currently inconclusive, based on the existing literature, whether Femoral Neck System (FNS) outperforms Cannulated cancellous screws (CSS) in all aspects. Due to variances in bone morphology and bone density between the elderly and young cohorts, additional research is warranted to ascertain whether the benefits of FNS remain applicable to elderly osteoporosis patients. This study aimed to investigate the biomechanical properties of FNS in osteoporotic femoral neck fractures and propose optimization strategies including additional anti-rotation screw.MethodsThe Pauwels type III femoral neck fracture models were reconstructed using finite element numerical techniques. The CSS, FNS, and modified FNS (M-FNS) models were created based on features and parameterization. The various internal fixations were individually assembled with the assigned normal and osteoporotic models. In the static analysis mode, uniform stress loads were imposed on all models. The deformation and stress variations of the femur and internal fixation models were recorded. Simultaneously, descriptions of shear stress and strain energy were also incorporated into the figures.ResultsFollowing bone mass reduction, deformations in CSS, FNS, and M-FNS increased by 47%, 52%, and 40%, respectively. The equivalent stress increments for CSS, FNS, and M-FNS were 3%, 43%, 17%, respectively. Meanwhile, variations in strain energy and shear stress were observed. The strain energy increments for CSS, FNS, and M-FNS were 4%, 76%, and 5%, respectively. The shear stress increments for CSS, FNS, and M-FNS were 4%, 65% and 44%, respectively. Within the osteoporotic model, M-FNS demonstrated the lowest total displacement, shear stress, and strain energy.ConclusionModified FNS showed better stability in the osteoporotic model (OM). Using FNS alone may not exhibit immediate shear resistance advantages in OM. Concurrently, the addition of one anti-rotation screw can be regarded as a potential optimization choice, ensuring a harmonious alignment with the structural characteristics of FNS.

Multi-objective optimization of HESS control for optimal frequency regulation in a power system with RE penetration

Concerns over fossil fuel emissions and their hazardous effects have led to a shift away from conventional power plants and focus more on the expansion of renewable energy sources. This shift has resulted in reduced inertia and resulted in poor frequency control within electrical power systems. Hybrid Energy Storage Systems (HESS) have been proposed as an effective solution to enhance frequency stability and address the reduced inertia issue. This research evaluates three distinct control models for HESS, Incorporating Supercapacitor Energy Storage (SCES) and Battery Energy Storage Systems (BESS). To optimize the control parameters with the best objectives, all possible sets of objectives with four different optimization algorithms are studied. The three control models considered for the HESS incorporate Virtual Synchronous Generator (VSG) or Virtual Inertia (VI) control with independent or simultaneous optimization of control parameters. The performances of the three control models are evaluated based on three test scenarios incorporating uncertainties, reduced inertia, and uniform and random load disturbances. The findings indicate that the Independently Optimized Virtual Synchronous Generator HESS (IO VSG-HESS) achieves the best settling time post-contingency but offers the least improvement in frequency nadir with an average of 0.31 %. Conversely, the Simultaneously Optimized Virtual Inertia And Virtual Synchronous Generator Controlled HESS (SO VI-VSG-HESS) excel in mitigating small frequency fluctuations with an average improvement in frequency standard deviation of 87.65 %. The Simultaneously Optimized Virtual Synchronous Generator Controlled HESS (SO VSG-HESS) provides the best frequency nadir, with an average improvement of 0.63 %, but with a slight increase in settling time.

Development and characterization of nitazoxanide-loaded poly(ε-caprolactone) membrane for GTR/GBR applications

ObjectiveGuided tissue/guided bone regeneration (GTR/GBR) membranes are widely used for periodontal bone regeneration, but their success depends on a bacteria-free environment. Systemic antibiotic treatment often proves inadequate, moreover, the increasing prevalence of antibiotic resistance in oral infections exacerbates this challenge. This study aimed to fabricate antibacterial membranes using a new class of antibiotics for local drug delivery, to eradicate infections and promote tissue regeneration. MethodsMembranes loaded with nitazoxanide (NTZ) were fabricated via electrospinning using poly(ε-caprolactone) (PCL) with varying concentrations of NTZ (0 %, 2.5 %, and 5 % w/w) relative to the polymer weight. Morphochemical of NTZ-loaded membranes were assessed using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and Fourier Transform Infrared spectroscopy (FTIR). Mechanical properties were evaluated using universal testing machine and NTZ release profile from membranes was determined by spectrophotometer (λmax = 444) for 14 days. Antimicrobial efficacy against periodontal pathogens, cell compatibility and mineralization were evaluated using periodontal ligament stem cells (PDLSCs). ResultsOptimized spinning parameter maintained a uniform fiber diameter and successful loading of NTZ was confirmed by SEM-EDS and FTIR. NTZ incorporation did not significantly affect mechanical properties, whereas the drug release kinetics showed an initial burst, followed by sustained release over 14 days. NTZ-loaded membranes demonstrated antibacterial activity against Aggregatibacter actinomycetemcomitans (Aa) and Fusobacterium nucleatum (Fn). Importantly, the presence of NTZ showed minimal cell toxicity; however, it reduced the mineralization potential compared with that of the pure PCL membrane, which increased over time. SignificanceTaken together, these findings established that NTZ-loaded membranes could be promising barrier membrane to counteract microbial environment and aid periodontal bone regeneration.

Fragility analysis of long-span lightweight steel structures subjected to combined earthquake and non-uniform snow loads

Lightweight steel structures are commonly used in industrial facilities due to their low weight, high strength, and excellent performance. The design of these structures for cold regions not only has to consider the effects of earthquakes but also the negative impact of snow loads. Industrial structures often have long spans, and the effects of uneven snow loads cannot be underestimated. However, relatively few studies have focused on the performance of lightweight steel structures under the influence of combined earthquake and non-uniform snow loads. Therefore, this study assessed the seismic fragility of a typical single-span, double-sloped lightweight steel factory under combined earthquake and non-uniform snow loads using incremental dynamic analysis. Non-uniform snow loads, as compared to uniform snow loads, substantially increase the structural displacement responses, thereby increasing the structural failure risk. The improved structural design developed in this study effectively decreases the impact of adverse loading scenarios and enhances the multi-hazard resilience of the structure. Accordingly, these results can serve as an important theoretical guide for enhancing the safety of lightweight steel structures subjected to multiple hazards in cold regions.

Evaluation of the strain energy during the interaction between micro-crack and semi-infinite crack in a brittle material

The main goal of this research is to evaluate the strain energy in a brittle material during the interaction of the semi-infinite crack with a neighboring micro-crack. The problem is formulated by considering a cracked thin plate having a micro-crack that rotates around itself and around the semi-infinite crack whose the cracked plate is subjected to a uniform load under mode I. During the interaction between the semi-infinite crack and micro-crack, the strain energy and stress field can be generated at the crack tip of semi-infinite crack. The theoretical analysis of this interaction is treated mathematically by the complex potentials functions. It is shown that the positioning of the micro-crack relative to the semi-infinite crack leads to amplification, reduction and absorption of the strain energy at the crack-tip. The theoretical results agree with those found numerically.