The heat transfer coefficient (HTC) is critical for hot stamping and in-die quenching. The air gap at interface is a dominant factor affecting the HTC, which is normally resulted from initial tooling clearance and thinning of deformed aluminum sheet. To precisely determine the HTCs under different air gaps, this research performed a comprehensive investigation on determining HTCs between an AA7075

This paper reports the tensile, impact, and mode-I behaviour of glass fiber-reinforced polymer (GFRP) composites modified by incorporating graphene nanoplatelets (GnPs) on the fiber surface and in the epoxy matrix. The composites were fabricated through a hand lay-up technique followed by hot compression moulding. The homogeneous dispersion of GnPs in the matrix was achieved by mechanical mixing followed

Masonry was the most used material during the last centuries to build constructions. Most of the existing masonry structures (buildings, bridges, etc.) were built without considering some important structural considerations that are important nowadays. Moreover, due to factors such as the increasing of service loads, materials aging, structural damage, etc., the existing masonry structures require

Ductile linings have been proved to be highly effective for tunnelling in heavy squeezing grounds. But there still has not been a well-established design method for them. In this paper, an investigation on an analytical design method for ductile tunnel linings is performed. Firstly, a solution in closed form for ground response of a circular tunnel within Burgers viscoelastic rocks is derived, accounting

Although, the friction method is well known for metals surface modification, the novelty of the article is based on the new idea of ceramics surface treatment with metal. The paper describes AlN ceramic metallization process by titanium coating deposition, obtained in friction surfacing method, which has been developed by the authors. The friction energy is directly transformed into heat and delivered

In this article, we propose a new class of metal-polymer architected sandwich structures that exhibit different mechanical behaviors. These lightweight sandwich structures have been made of aluminum face sheets and 3D-printed lattice cores with 2D (Bi-grid, Tri-grid, Quadri-grid and Kagome-grid) and 3D (face-centered cubic-like and body-centered cubic-like) topologies. Finite element simulation and

Ti–6Al–4V (TC4) and Ti–6.5Al–3.5Mo–1.5Zr–0.3Si (TC11) joints were achieved via Ti–37.5Zr–15Ni–10Cu (wt%) filler metal when the brazing temperature was in the range from 950 °C (below β-transus) to 1040 °C (above β-transus) for 10–60 min. The role of brazing parameters in the microstructure evolution as well as mechanical properties of both base alloys and brazed joints was studied. The research analysis

The single-crystal superalloy materials have been rapidly developed and widely used in advanced thermal structural components due to their excellent comprehensive physical and chemical properties under high-temperature service conditions. However, conventional micro-hole making results in defects such as edge breakage and burr. In this study, the electrical discharge drilling (EDD) combined with helical

The paper explores the new method of improving the workability of materials in the dieless drawing processes. The proposed method is based on the implementation of a multi-pass incremental deformation. Moreover, in each pass, strain and strain rate sensitivity of flow stress should be positive and significant. An approach based on the finite element calculation of instability coefficient of plastic

New concepts proposed for processing of dual phase (DP) steels as one of the main classes of advanced high-strength steels (AHSSs) to enhance their mechanical properties (strength–ductility combination) and corrosion resistance were introduced. The current review covers (I) the processing routes to obtain the ferritic–martensitic microstructures, (II) parameters of intercritical annealing (IA) treatment

Friction spot extrusion welding process is successfully performed on dissimilar aluminum alloys of AA2024-T3 and AA6061-T6 under the influence of shoulder features. The joints were analysed by microstructural features and mechanical properties using conventional and advanced tools of visual inspection, optical microscopy, scanning electron microscopy, transmission electron microscopy, electron back

Copper–alumina composites of the interpenetrating networks type are interesting materials for many applications because of their properties. On the base of preliminary investigations and practical works, in order to obtain a material with high resistance to friction wear as well as good dissipation of heat generated during work, it was decided that a developed material would be prepared on the base

The welding of nitrogen (0.29 wt%)-alloyed austenitic steel (grade 23-8-N) was performed with gas metal arc welding process. Solution treatment was performed at 950 °C and 1150 °C on base metal prior to weld. Base metal after second treatment has maximum ultimate tensile strength of 942 MPa and impact toughness 66 J. The microstructures of different zones of the weld joint were characterized using

This paper presents the design, modeling, fabrication, and test of a monolithic compliant gripper for micro-manipulation applications. A compact compliant mechanism that enables in-principle straight-line parallel jaw motion is obtained, by combining the Scott–Russell mechanism and the parallelogram mechanism. The right-circular corner-filleted (RCCF) flexure hinge is adopted to achieve a large displacement

The hydraulic support column of comprehensive mining equipment is the most important part, subjecting to corrosion, wear and collision. The scrapped columns are restored by laser cladding to replace plating process for enhancing service life. All that is required after laser cladding is subtractive machining to improve the surface quality of the laser cladded coatings. This work focused on the remanufacturing

A set of ultrasonic burnishing equipment with two different burnishing tips was designed and manufactured, with which a series of experiments were performed to explore the effects of process parameters and burnishing tips on the surface integrity of austenitic stainless steel material being treated by ultrasonic burnishing (UB). Based on the experiment data, the two surface treatments, i.e. UB with

This article deals with the subject of layers produced in a hybrid process combining hardfacing and nitriding. These layers are characterized by improved resistance to wear, which arises from the synergy between favorable materials during hardfacing and nitriding treatment. Tests were conducted on hot-work tool steel (H11) samples. Hardfaced layers consisting of three layers were applied to these samples

Within the framework of this study, the 1050A/AZ31 round bimetal bars were produced by the explosive cladding method and subsequent groove rolling process. LM/SEM investigation shown that by proper selection of the explosive cladding parameters (mainly initial distance between 1050A tube and AZ31 core and detonation velocity) it is possible to produce 1050A/AZ31 feedstocks without a continuous layer

For the first time, the analytical electron microscopy has been used to determine the solute concentration profiles left behind the moving reaction front (RF) of the discontinuous precipitation (DP) reaction in a Fe-13.5 at.% Zn alloy. These profiles have been converted into grain boundary diffusivity (sδDb) values, using Cahn’s diffusion equation in its original form and the data of the growth rate

Circular concrete filled double skin steel tubular (CFDST) has broader application aspects in engineering practice due to its superior confinement and elegant architectural appearance compared with square CFDST. However, there is still lack of an effective and reliable assembled method to connect the circular CFDST column to the beam. This paper focused on the theoretical and structural behavior on

3D printing technology is currently used in various fields. Precision is also becoming more important as the usage of the 3D printing increases. However, the precision of the 3D printing is still low due to limitations of manufacturing methods. Especially, the surface roughness and quality are inconsistent. While the post-treatment is necessary, there are no systematic post-treatment methods. Thus

This paper proposes a new type of bolted glulam joint for small-span and medium-span reticulated timber dome structures. The joint fastens the timber elements and the angled slotted-in steel plates together with steel bolts. Reasonably simplified experiments were designed and conducted to understand the mechanical properties of the proposed joint. Finite element models were also developed and calibrated

The failure mechanisms of coatings, under high thermo-mechanical loads, can be examined through finite element simulations. However, mechanical properties such as Young’s modulus and Poisson’s ratio are necessary to achieve an accurate model. In this study, nickel–aluminum with hexagonal boron nitride (NiAl/hBN) is deposited on stainless steel 304 substrate using atmospheric plasma spray technique

In recent years, the composite materials have been very desirable by researchers for many engineering applications such as aviation and biomedical because of the tremendous characteristics of magnesium matrix metal composite. This current investigation aims to develop the AZ91/SiCp composites with various weight fractions (0, 2.5, 5 and 10 wt%) of silicon carbide particles via the stir casting method

Cross wedge rolling (CWR) is one of the most effective plastic deformation methods utilized for the production of shaft parts or non-shaft preforms with refined grains and improved mechanical properties. The main goal of this work was to study the influence of CWR process parameters on the microstructure evolution and mechanical properties of a TC6 alloy and determine the suitable process parameters

This study relates to an innovative method for forming rail car axles by skew rolling in a CNC 3-roll mill. The rolling mill was constructed at the Lublin University of Technology. The use of this machine makes it possible to produce elongated axisymmetric parts that are up to 55 mm in diameter and up to 1000 mm in length. Experimental rolling tests are performed (in 1:5 scale) using this machine.

The paper describes the results obtained from the tensile and compression experimental tests of the structural tempered glass plates with three different types of stress concentrators and without them. The types of stress concentrator have been chosen as close as possible to those usually found in practical situations and also taking into account the cases known from the literature. All tests are performed

The concept of quasi-zero-stiffness (QZS) vibration isolator was proposed in recent decades to improve the low-frequency isolation performance without increasing the static displacement. This work is devoted to the concrete realization of a QZS isolator by utilizing transverse groove springs. Firstly, the QZS isolator is theoretically analyzed and some dynamical indices are analytically calculated

Duplex high-carbon steel is widely used in ball mills in the form of grinding balls and thus subjected to impact loads during the normal operation of the mill. The influence of impact loading at different impact energies is investigated in this paper. Impact tests using a drop tower were performed in the regime of 100–150 J, and the mechanical response of the material was recorded. The deformation

Under certain extreme conditions in rock engineering works, fast change in temperature in the load-bearing rocks can happen. Known as thermal shock (TS), such process involves rapid temperature rise or drop, which causes fracturing in the rock material and thus can pose as a threat to the stability of the rock structures. To investigate the influence of thermal shock caused by fast cooling on the mechanical

A method has been developed for determining residual stress based on displacement fields near drilled holes analyzed using 3D digital image correlation. Finite element modeling was used to determine corrections for analytical equations describing displacement fields near the blind holes, which made it possible to determine the residual stress distribution over a wide range of hole depth-to-hole diameter

This paper presents a new metallic damper called hexagonal honeycomb steel damper (HHSD) for damage mitigation in structures subjected to earthquake excitations. The HHSD is composed of steel plates having several hexagonal and welded to the top and bottom anchor plates. The damper takes the advantages of hexagonal honeycomb geometry and steel material capability to dissipate seismic energy. The quasi-static

The paper addresses numerical simulations of a concrete vehicle restraint system. The model is described in detail. The advanced material law of the continuous surface cap model was used to analyze the damage locations in concrete barrier segments. The results were validated against the TB41 full-scale crash test. The test was conducted in compliance with European standard EN 1317, and the validation

High-power fiber laser has been proven to be feasible for cutting carbon fiber reinforced polymers with several advantages including noncontact force, high efficiency and flexibility, while the characteristics of thermal damage and heat conduction in materials are not yet fully understood. Continuous-wave fiber laser was applied in this work to cut 2.0-mm-thick carbon fiber reinforced polymer laminates

The light polymer material (LPM), prepared with suitable mix proportion and physical method, is a type of low-carbon and environmental-friendly material. Recently, the LPM is developed as structural material for cold-formed steel (CFS) structures to cover the shortages of traditional CFS shear wall. In this paper, material properties of gypsum-based and cement-based LPM including compressive strength

High strength biodegradable surgical threads are in demand for surgical practice. Nowadays, such threads can be made of metallic materials such as magnesium, zinc or alloys based on these metals. In current paper, manufacturing technology of biodegradable surgical threads of Mg–Ca alloys and of pure Zn was developed and basic properties of the obtained product have been characterized. The influence

In this study, two groups of the cement-matrix nanocomposites (CMNC) were produced. The first group was reinforced with either carbon nanotubes (CNT) or graphene oxide (GO), where the equivalent weight% of cement equaled 0.05, 0.1, and 0.15. The second group was reinforced with the hybrid CNT–GO, where the equivalent weight% of cement equaled 0.05 CNT–0.1 GO and 0.1 CNT–0.05 GO. Before producing nanocomposites

Fly ash is a well-known supplementary cementitious material that is the by-product of coal-fired thermal power plants. The contribution of fly ash to the enhancement of the mechanical and durability properties of cementitious materials has been documented in concrete technology for many years. In this study, to allow superior mechanical and durability properties, fly ash-based mixtures have been produced

Flexural performance of concrete beams reinforced with steel–FRP composite bar (SFCB) was investigated in this paper. Eight concrete beams reinforced with different bar types, namely one specimen reinforced with steel bars, one with fiber-reinforced polymer (FRP) bars and four with SFCBs, while the last two with hybrid FRP/steel bars, were tested to failure. Test results showed that SFCB/hybrid reinforced

The innovation of traditional machinery manufacturing and the promotion of advanced manufacturing technology are becoming the booster for the sustainable development of automobile industry. This paper aims to propose a promising manufacturing technology driven by electromagnetic impact, which is called as electromagnetic high-speed nailing. In this paper, the connection mechanism and joint performance

AISI 304L stainless steel is most commonly used for spent nuclear fuel management; however, the welded joints of this steel are susceptible to intergranular stress corrosion cracking (IGSCC) under the influence of low-temperature sensitization. In the present research, the temperature history of two different groove designs (conventional and narrow groove) has been analyzed to ascertain the propensity

Mechanical behavior of a multifunctional titanium alloy Gum Metal was investigated by conducting tensile tests at various strain rates and applying digital image correlation (DIC) technique. Stress–strain curves confirmed low Young’s modulus and high strength of the alloy. The determined values of yield strength had a tendency to increase, whereas the elongation to the specimen rupture tended to decrease

Earthmoving vehicles, especially ones with articulated frame steering, are very vulnerable to rollover. Consequently many dangerous rollover accidents occur all around the world. This problem is not only caused by difficult operating conditions and high productivity requirements. The current standards in this area do not offer an acceptable method of assessing vehicle rollover stability. Furthermore

Abstract Sheet metal forming belongs to one of the most important technologies enabling the production durable but quite lightweight metal parts. The quality of the drawn parts depends on the deformed sheet metal, applied forming technology and process parameters, such as contact pressure, relative velocity, temperature or lubrication. The forming of steel (1.4021) parts using benign lubricant is analysed

Nowadays, the main limitation for clinical application of scaffolds is considered to be an insufficient vascularization of the implanted platforms and healing tissues. In our studies, we proposed a novel PLA-based hybrid platform with aligned and random fibrous internal structure and incorporated calcium phosphate (CaP) ormoglass nanoparticles (0, 10, 20 and 30 wt%) as an off-the-shelf method for obtaining

Nanoindentation test was employed to measure the actual hardness and yield strength of the stir zone in the friction stir-welded single-phase brass joints. For this aim, different joints were prepared according to an experimental matrix based on the central composite rotatable design. In this design matrix, the tool rotational speed, tool traverse speed, and tool axial force were the input parameters

This paper examines the experimental performance of ultra-high-performance steel fibre-reinforced concrete (UHPSFRC) beams subjected to loads at relatively low shear span-to-depth ratios. The results and observations from six tests provide a detailed insight into the ultimate response including shear strength and failure mode of structural elements incorporating various fibre contents. The test results

At nanoscale, surface free energies of the atoms located on the free surfaces of structures significantly affect their mechanical characteristics. In this study, nonlinear large-amplitude free vibration response of nanoshells prepared from functionally graded porous materials (FGPM) is investigated by taking into account surface stress size effects and vibrational mode interactions. Non-classical shell

Temperature changes due to hydration heat often cause cracks in the early-age concrete deck of steel–concrete composite girder bridges, even before opening to traffic. However, no available methods are provided in current specifications for the thermal effect calculation. To fill this gap, large-scale temperature measurements and fine finite-element model (FEM) analysis were performed on an actual

This study examines the effects of fiber geometry, spacing, and loading rate on the pullout resistance of steel fibers in ultra-high-performance concrete (UHPC). For this, three different types of steel fibers, four different fiber spacings, and three different loading rates ranging from 0.018 to 740 mm/s were considered. Test results indicated that the single straight fiber in UHPC was most rate sensitive

Investigated in this paper is the first on the moving-load-caused nonlinear coupled dynamics of beam-mass systems. A constant value load excites the beam-mass system where its position on the beam-mass system changes periodically. The energy contribution of the moving load is included via a virtual work formulation. The kinetic energy of the mass together with the beam as well as energy stored in the

This paper focused on the seismic performance of buckling-restrained braced concrete frame. Two different systems including the single-level yielding buckling-restrained braced concrete frame (SYBRBCF) and the double-level yielding buckling-restrained braced concrete frame (DYBRBCF) were designed for comparison. Compared with the single-level yielding buckling-restrained braces which are similar to

Here, ultrasonic–wave–assisted gas tungsten pulsed arc (U–GTPA) welding is proposed as a new alternative welding process to gas tungsten arc (GTA) welding. To better understand the advantages of this new process, in this paper, the microstructure, mechanical properties and corrosion behavior of GTA- and U–GTPA-welded joints of 316L stainless steel are systematically compared. These results show that

Laser cladding has been commonly utilized for restoring high value-added parts. However, the poor surface quality becomes key technological barrier which restricts its widespread applications. In the paper, re-contouring strategies by machining method are explored for minimal energy consumption as well as required surface roughness. Firstly, the effect of structural characteristics of the laser-cladded

To investigate the influence of corroded steel bars on seismic performance of reinforced concrete (RC) columns, eight full-scale RC columns were designed and fabricated, which were composed of one uncorroded RC column, three RC columns with longitudinal reinforcement corrosion and four stirrup-corroded RC columns. The electrochemical test was conducted to accelerate the corrosion of steel bars in RC

Layered metallic materials (LMMs) offer superior properties in comparison to their counterpart monolithic sheets. Single-point incremental forming (SPIF) has emerged as an economical solution to produce LMM parts. However, delamination can limit the formability of such parts. In this study, the delamination analysis during SPIF of layered sheets was performed. Steel/steel bi-layer sheets were fabricated

Ultra-high molecular weight polyethylene (UHMWPE) is one of important materials utilized against impacting threats. In this work, bulk UHMWPE specimens were fabricated in a compression molding chamber, and molding parameters such as pressure and temperature were varied in the specimen preparation stage to investigate the effect of molding parameters on the impact performance. In addition, silicon carbide

Abstract The civil infrastructures constructed using self-compacting concrete (SCC) reinforced with fiber-reinforced polymer (FRP) bars are advocated for engineering applications due to corrosion resistance and environmental-friendly performance. The bond behavior between FRP reinforcement and SCC is a significant factor affecting the serviceability and failure mechanism of this composite structure

The nonlinear finite element analysis of pin-supported reinforced concrete slabs of moderate thickness is the main subject of this paper. This is an important issue of the mechanics of concrete structures. Thus, a nonlinear FE analysis of RC slab models subjected to punching shear was initiated and the comparison of the numerical and test results was made. The prediction engine of the crack pattern

The growth of lamellar structure during discontinuous precipitation occurs frequently by so-called go-and-stop fashion. The results of simulation combined with the changes of Cahn’s parameter C revealed two types of such motion. The process takes place in the successive stages which can be distinguished judging from the value of C parameter. For lower values of linear growth rate (v = 10÷20 nm/s) and