This paper investigated the relationship between the strength of fractured rock and the crack propagation process. A series of uniaxial compression tests were carried out on the rock-like material specimens with single pre-fabricated flaw. Moreover, DIC (digital image correlation) technology was utilized to monitor and analyze the failure process of specimens. The initiation of each crack was defined

The article presents the profit optimization model for multi-unit construction projects. Such projects constitute a special case of repetitive projects and are common in residential, commercial, and industrial construction projects. Due to the specific character of construction works, schedules of such projects should take into account many different aspects, including durations and costs of construction

When a metro is constructed by the shield method in the strata containing boulder group, it is prone to some engineering problems such as serious cutter wear, deformation of the cutter holder head, damage of the cutter spindle, which seriously affects the construction efficiency and bring enormous problems to the shield construction. This paper proposes the vibration reduction measures for the boulder

Recent research in engineering seismology demonstrated that in addition to three translational seismic excitations along x, y and z axes, one should also consider rotational components about these axes when calculating design seismic loads for structures. The objective of this paper is to present the results of a seismic response numerical analysis of a mine tower (also called in the literature a headframe

Burzynski criterion is a well-known criterion is employed for pressure-sensitive isotropic materials. In the current study, this criterion is modified for asymmetric anisotropic materials called hear MB. Firstly, a modified deviatoric stress tensor is defined with a linear transformation to consider the anisotropy effects of materials. Secondly, MB is presented by the sum of n-components to have more

This paper reports on a comprehensive research on the performance of self-centering masonry walls (SMWs). A summary of an experimental study is presented. Finite element (FE) study was performed and verified against experimental results to predict the behaviour of SMWs. Using the verified FE modelling; Phase I of a parametric study was conducted aiming at developing a refined approach to better predict

The development of an efficient numerical approach for the generation of a wide range of heterogeneous microstructures models with the application of the lean workflow concept is presented in the paper. First, the idea and implementation details of the developed cellular automata-based computational library allowing the development of digital material representation models within a workflow are presented

The warm roll bonding technique was adopted to fabricate Aluminum–polyurethane–Aluminum (Al–PU–Al) composites. Glass whiskers or SiC particles were added to reinforce the inner layer. The main objective of the present study is to examine experimentally the main manufacturing parameters, including interface properties and layer thicknesses, both of which control the strength and integrity of Al–PU–Al

In spite of an increasing number of rubber-tracked vehicles, there are no engineering models for predicting and optimizing the energy consumption of vehicles of this type. To formulate those models, the models of the phenomena resulting in the internal losses of rubber-track systems need to be developed. This article presents a model describing the losses caused by the transverse vibrations of rubber

Until recently, the strengthening efficiency of carbonaceous reinforcements in aluminum-based matrix nanocomposites (AlMNCs) was lower than expected. The intrinsic characteristics of matrix and carbonaceous reinforcements and fabrication technique, which affected the microstructural characterization, played main roles in determining the performance of Cs/AlMNCs. In this study a novel strategy was developed

A correction to this paper has been published: https://doi.org/10.1007/s43452-021-00213-7

This article is detected to the assessment of durable deformations of recycled mixtures made of foamed bitumen (MCAS) and emulsion (MCE). In the basic part of research and analyses, attention was focused on determining the scale of three-component composition modifying rheological phenomena of recycled mixtures and other selected features considering various methods of bituminous binder proportioning

This paper describes an experimental investigation into confinement effects provided by circular tubular sections to rubberised concrete materials under combined loading. The tests include specimens with 0%, 30% and 60% rubber replacement of mineral aggregates by volume. After describing the experimental arrangements and specimen details, the results of bending and eccentric compression tests are presented

The mechanical performance of beam-to-column connections plays an essential role in the design of post-and-beam glulam structures. This paper presents an investigation into the mechanical performance of glulam beam-to-column connections with coach screws as fasteners. A series of monotonic and reversed cyclic loading tests were conducted on the beam-to-column connections with coach screws, and the

Fibre metal laminates (FMLs) are attractive construction materials, especially for use in aerospace and transport facilities. Throughout their service life, thin-walled structures made of FMLs are exposed to static and dynamic loads, as well as corrosion and the unfavourable influence of environmental conditions. The paper presents an experimental analysis of the combined mechanical and environmental

This paper presents an innovative system determining machine tool quasi-static stiffness in machining space, so-called Stiffness Workspace System (SWS). The system allows for the assessment of the accuracy of a machine which has become a vital aspect over past years for machine tool manufacturers and users. Since machine tools static stiffness is one of the main criteria using to evaluate the machines'

The article presents studies of phase transformations taking place in surface layers of nitrided steels as a result of their annealing at 520 °C for 5 and 10 h. Two steel grades were tested, the unalloyed AISI 1085 and the low-alloy AISI 52100. As a result of glow discharge nitriding, at 570 °C/5 h and 540 °C/12 h, respectively, nitrided layers were produced on the steels, consisting of a surface layer

This paper aims to evaluate the seismic performance of concrete filled double-skin steel tubular (CFDST) frame structures. An experimental investigation on internal joints to CFDST columns was conducted to assess their seismic behavior, in which non-welding connection method was employed to avoid possible premature welding fracture. Experimental results declared that this type of joint behaved in a

Understanding the mechanical properties plays pivotal roles in rock engineering. This work aims to establish novel relations linking the porosity, ultrasonic wave and fluid saturation to estimate the uniaxial compressive strength (UCS) fast and simply. The uniaxial compressive coupled with ultrasonic wave tests on sandstone samples are carried out to obtain the datasets of the UCS, P-wave and S-wave

The experimental characterization of the material under shear loading is essential for researchers to study the plastic behavior of materials during manufacturing processes. Indeed, regardless of the loading mode, ductile materials mainly deform plastically under shear loading. Thus, for such material behavior analysis, shear tests are very useful. In this paper, a test procedure is defined to characterize

Shear-assisted processing and extrusion (ShAPE) experimental setup and tooling were adopted for extruding thin-walled AA7075 aluminum tube from as-cast non-homogenized billet material in a single run. The mechanical and microstructural characterizations were performed on the as-extruded tube through tensile, hardness, electron backscatter diffraction (EBSD), and energy dispersive spectroscopy (EDS)

Civil engineering projects deal with different risks over their life-cycle. Generally, risk sources are categorized into three types of cost, time, and project quality. The Modified Advanced Programmatic Risk Analysis Model (MAPRAM) is one of the leading approaches in this field that can assess the risks of the project on its whole life cycle. Electricity transmission lines have always been one of

In this study, the finite element method (FEM) is used to study the ploughing effect of ultrasonic vibration-assisted cutting Ti6Al4V. Due to the existence of the cutting edge radius of the tool, there will be a ploughing area in the cutting of Ti6Al4V. The ploughing area is an area where the stress state is very complex in the cutting process. The ploughing force and temperature of the ploughing area

In the present study, the grinding experiment of second-generation nickel-based single-crystal superalloy DD5 was carried out under different grinding parameters. The grinding force was recorded during the grinding process, and it was found that it decreased with increasing grinding speed and increased with feed speed. The microstructure evolution of ground subsurface was obtained by optical microscope

This paper aims to investigate the performance of thin-walled circular stainless steel-carbon steel bimetallic tube confined concrete slender columns under eccentric compression. 14 slender columns including bimetallic tube confined concrete (BTCC) with and without rebar, and concrete-filled bimetallic tube (CFBT) were tested. A parametric analysis is conducted based on the validated finite-element

The research focused on effective utilisation of fly ash (FA) from municipal waste incineration plants. FA was found to have an effect on rheological characteristics (viscosity) of cement pastes, to suppress cement hydration processes. Evidence was obtained that up to 10% of FA in hardened cement paste and mortars does no impair compressive strength characteristics. XRD analysis and SEM tests revealed

The effects of the working temperatures (260 °C, 200 °C and 130 °C) on microstructure formation in the AA 6063 alloy, processed upto ten passes by cyclic expansion extrusion (CEE) was studied. The microstructures of the CEE-processed specimens in the convergent and extrusion regions (center and edge) were examined after every two passes. The EBSD analysis revealed a decrease in the average grain size

Tungsten borides (WBx; x = 2.5 or 4.5) with an increasing substitution of tungsten by zirconium from 0 to 24 at.% were synthesized by spark plasma sintering (SPS) for the first time. The influence of the holding time (2.5–30 min) on the densification behavior, microstructure evolution and development of the properties of W–Zr–B compounds were studied. The samples were characterized using scanning electron

A novel pile-plank-supported ballastless tram track is employed in southeast of China to mitigate the foundation differential settlement in soft soil regions. In this structure, the channel rails are directly combined with the plank by fasteners and pads. In situ measurement data reveal that the foundation differential settlement is well controlled by this structure and the internal forces of the plank

The kinetics of heat transfer in hardening concrete is a key issue in engineering practice for erecting massive concrete structures. Prediction of the temperature fields in early age concrete should allow for proper control of the construction process to minimize temperature gradients and the peak temperatures, which is of particular importance for concrete durability. The paper presents a method of

Plastics are more and more frequently applied in the construction of hydraulic components and systems, and recently, in the building of microhydraulic assemblies. The basic unit of the microhydraulic systems is a micropump. It is an object which is quite difficult to design and manufacture, especially when using plastics. The paper is a presentation of challenges that must be met in the process of

An analytical solution has been developed developed in this research for electro-mechanical flexural response of smart laminated piezoelectric composite rectangular plates encompassing flexible-spring boundary conditions at two opposite edges. Flexible-spring boundary structure is introduced to the system by inclusion of rotational springs of adjustable stiffness which can vary depending on changes

Ultrasonic vibration technology has been widely applied in plastic forming processes due to its advantages of material properties improvement. In this study, a transverse ultrasonic vibration-assisted compression (TUVC) system with the range of vibration amplitude from 16 to 48 µm is developed to compress the difficult-to-deformation materials. The experiment found that the temperature of the compressed

This fundamental research deals with the investigation of material property model influences on distortion induced by multi-layered Wire Arc Additive Manufacturing (WAAM) with synergic-pulsed gas metal arc welding (P-GMAW) process which was modelled and simulated by means of non-linear numerical computation. The material property models of stainless steel SS316L component to be compared stem from three

The effects of polyurea coating on anti-explosion performances of reinforced concrete arches were studied through explosion experiments. Three coating schemes were proposed and investigated, including intrados coating, enclosed coating and fiber-grid/polyurea hybrid coating. The arches exhibit cracking, spalling and crashing failure modes in succession accompanying with reducing the scaled distance

Recent progress in the kinetics of grain coarsening and abnormal grain growth (AGG) is presented in this overview article. The factors affecting the kinetics of grain growth is reviewed with the emphasis on the recent findings on the solute drag and Zener pinning effects as well as the special case of duplex alloys, where the latter is discussed for the behavior of dual-phase steels during intercritical

Material properties largely depend on their structure, and are strongly dependent on the scale of observation. Under the influence of various processes, the structure of a material can undergo evolution, which leads to major changes in the mechanical parameters and morphology of the medium. To understand the behaviour of a given material exposed to the influence of various factors, e.g. loading and

This article presents the main problems associated with cereal harvesting in sloping areas. The presented innovative aerodynamic system supporting the separating unit of combine harvester can be one of the ways to counteract the negative effects of harvesting machines work on slopes. The Monte Carlo numerical method, presented in this article, was applied in the optimization of an aerodynamic sieve

There are only a few smelters processing copper concentrates directly into blister copper. Despite the many advantages of this process, a serious challenge of this technology is the need to process the resulting flash smelting slag. It contains 12–15% copper and 2.5–4% lead. In this form, it cannot be considered as waste material and, therefore, a high-temperature reduction process is carried out.

The paper presents results of FEM modelling as well as properties and microstructure of the ultralow-carbon ferritic steel after the unconventional SPD process—DRECE (dual rolls equal channel extrusion). Based on the conducted numerical simulation information about the deformation behaviour of a steel strip during the DRECE process was obtained. The simulation results were experimentally verified.

3D concrete printing has received widespread attention and been developed for an increasing number of applications. However, a major challenge facing this technology is an effective way to introduce reinforcement into continuously deposited cementitious material. In this study, different layers of steel wire meshes (SWM) are employed to reinforce the 3D printed structures to improve mechanical capacities

This paper proposed an electromagnetic loading process with the high-speed impact. Al-4.2% Cu alloy bars were used to employ electromagnetic impact (EI) experiments. Deformation mechanism and microstructure evolution of EI samples were revealed by theoretical model and microstructure characterizations. The EI process had impact force (peak value 40 kN) and impact velocity (peak value 6.7 m/s) during

The ability to improve rock-breaking efficiency of tunnel boring machines in hard rock stratum is significant to improve driving speed and reduce construction cost and time. The undercutting method has been used to improve the rock-breaking efficiency of disc cutters, including the design of curved and multistage cutterheads. The limited radian of curved cutterheads and the number of multistage cutterheads

Single-crystal superalloy is characterized by no grain boundary and widely used in the aviation and aerospace industry due to its high creep strength and high thermal fatigue resistance, especially applications in aero engine necessitate numerous micro-scale structures made of single-crystal superalloy material with high-dimensional accuracy and surface quality. Micro-grinding as one of micro-precision

This study addresses some aspects regarding a computer modelling based on three-dimensional Frontal Cellular Automata (FCA) for the simulation of ultrafine-grained (UFG) microstructure development in purpose-designed microalloyed austenite model alloy i.e. FCC structure. Proposed in the present study model is a step forward towards understanding the deformation and microstructure development mechanisms

The thermal and mechanical stabilities of retained austenite in aluminum-containing medium-Mn 0.16C–4.7Mn–1.6Al–0.2Si sheet steel were investigated. The strain-induced martensitic transformation in Mn TRIP steel was studied at different temperatures. Static tensile tests were carried out at the temperature ranging from − 60 to 200 °C. The tests allowed to study the influence of the temperature on

Steel–concrete–steel (SCS) structural systems have economic and structural advantages over traditional reinforced concrete; thus, they have been widely used. The performance of concrete made from recycled rubber aggregate from scrap tires has been evaluated since the early 1990s. The use of rubberized concrete in structural construction remains necessary because of its high impact resistance, increases

This study investigates the effects of horizontal ground motion incident angle on a high-speed railway continuous bridge (HSRCB). To that end, incremental dynamic analyses (IDA), seismic vulnerability analyses and seismic risk assessments were conducted on a three-span HSRCB subjected to a set of ground motions under five incidence angles θ (0°–90°). The analysis was developed only from the perspective

Incremental hole flanging (IHF) is a relatively new sheet metal forming process to produce intricate shapes without using dedicated punches and dies. The present work focuses on understanding the mechanics of the multi-stage IHF process through experimental studies and the finite element approach. The IHF experiments were performed on deep drawing quality steel sheets with a pre-cut hole diameter of

To reduce the self-weight of bamboo-concrete composite (BCC) beams and realize rapid industrial production, innovative assembled bamboo-lightweight concrete composite (ABLCC) beams are presented for use in engineering structures. To verify the structural performance of the ABLCC beams, a series of bending tests were performed on the bamboo beams, the cast-in-place bamboo-lightweight concrete composite

High solidification cooling rates during unsteady-state conditions of solidification of Al-based alloys can induce different microstructural length scales or metastable phases, leading to improved properties. The present study aims to characterize the microstructural arrangement of the hypereutectic Al–8 wt%Ni alloy, unidirectionally solidified in unsteady-state heat flow conditions, examining the

Steam-cured concrete with high early strength has been widely applied in high-speed railway. However, heat damage caused by the steam curing process brings adverse effects on the pore structure and durability of steam-cured concrete. It has been found that phase change materials (PCMs) help improve the durability of cement-based materials. Therefore, the influences of two PCMs on the strength, water

The modified friction stir clinching (MFSC) of 5083 aluminum alloy to brass using pure Zn interlayer has been explored and elucidated for the first time. By that, the influence of the Zn interlayer thickness on the microstructure and the mechanical properties of the 5083/brass joint was investigated. The attained data have revealed that the intermetallic compound (IMC) layer thickness was mainly influenced

The selection and use of high strength alloys with high wear resistance (at room and high temperature) are mandatory in aerospace, nuclear, automotive, petroleum, space, furnace, and chemical industries in which Incoloy 800H superalloy is the right choice. However, this alloy is under the class of ‘difficult to cut material’ caused by their significant properties. In the present work, the heat treatment

Since a lot of medical facilities are made from normal weight concrete (NWC), it became an important task to improve the radiation shielding properties of such concrete in a confrontation to radiation with special emphasis on gamma radiation type. Therefore, an experimental program was conducted to investigate the effect of nanoparticles addition on gamma radiation shielding, physical properties, and