This study proposes a computational framework for modeling the multiaxial cyclic plasticity behavior of 304LN stainless steel under both synchronous and asynchronous strain-controlled loading. A series of biaxial fatigue experiments on thin-walled tubular specimens revealed pronounced nonproportional hardening and pathdependent plastic deformation, particularly under asynchronous loading conditions. To capture these effects, an advanced constitutive model was formulated by integrating multi-component kinematic hardening, a memory-dependent isotropic hardening rule, and a nonproportionality-sensitive internal variable. Model calibration was carried out using Bayesian Optimization, with kinematic hardening parameters trained on eighteen uniaxial hysteresis loops representative of various cyclic conditions to enhance the accuracy of simulated loop shapes. The finalized model was implemented in a finite element framework and validated across seven multiaxial loading paths. Simulations demonstrated high fidelity in reproducing hysteresis loop shapes, peak stresses, strain ranges, and stress path trajectories. Qualitative analysis indicates that asynchronous multiaxial loading in 304LN stainless steel results in elevated plastic strain accumulation and significant nonproportional hardening, effects that are closely associated with the newly introduced Desynchrony Index (DI). Experimental observations further demonstrate that asynchronous loading paths can produce cyclic hardening comparable to, or exceeding, that of classical out-of-phase loading, underscoring the importance of time-varying phase interactions in cyclic plasticity. The evolution of the nonproportionality parameter also shows strong agreement with experimentally derived desynchrony indices, reinforcing the robustness of the proposed approach for fatigue analysis under complex multiaxial loading conditions.

In this experimental study, the influence of wire electrical discharge machining (WEDM) process parameters—pulse-on time (Ton), pulse-off time (Toff), peak current (IP), and servo voltage (SV) —on the surface roughness and machining speed of the zirconium diboride-boron carbide (ZrB₂-B₄C-5

This study investigates the fatigue behavior of 304LN stainless steel under constant and variable strain path multiaxial loading conditions. Experimental methods and computational modelling were used to analyze the response of the material to different loading scenarios. Experimental investigations were conducted to gather empirical data, which were subsequently validated using a modified Ohno-Wang and Tanaka cyclic plasticity framework. Two models were used for the analysis: the MOT model and a modified model that incorporated a weighted function and fractional functions for hardening and softening. In contrast, the modified model offers significant improvements, accurately capturing primary hardening and secondary softening across all loading scenarios. Furthermore, the modified model effectively simulates transient behavior, including load alteration and recovery effects, due to the integration of load history memory regulating functions. Overall, this study emphasizes the importance of considering the complexities of cyclic loading and the sensitivity of the material behavior to the loading history.

Pedestrians are a crucial component of urban transportation but are vulnerable at unprotected mid-block locations, especially under mixed traffic conditions. At these locations, some vehicles may yield to pedestrians at crosswalks, but others may use forced gaps to cross the road. This behaviour can reduce vehicle flow and affect traffic conditions. This study aims to investigate the impact of pedestrian crossings on traffic flow characteristics, including speed, capacity and level of service. To analyse these effects, six-lane divided mid-block sections in urban areas were chosen. Videos were recorded at seven sites, including base and non-base sections, during peak and off-peak hours to collect data on traffic volume and speeds. The analysis shows that as traffic flow increases, speed reduces. The most pronounced speed reductions are at ECIL (18.04

The cyclic hardening/softening behaviour of C-Mn piping material has been studied in detail. The material exhibits cyclic hardening-hardening-hardening (H-H-H) at higher strain ranges, softening-softening-hardening (S-S-H) at lower strain ranges. Quantitative investigations of isotropic transformations show strain range dependent variation of cyclic yield strength. Higher translations of centre of yield surface have been observed at higher strain ranges. Present work has explored cyclic hardening/softening primarily due to variation of isotropic softening. The material exhibits additional hardening under multistep asymmetric strain cycling. New multi-objective plasticity model has been developed, results in excellent prediction of cycle-cycle behaviour, H-H-H, S-S-H, additional hardening till failure.

The present work has been aimed at developing an improved cyclic plasticity model in the framework of OhnoWang kinematic hardening formulation and evaluating the performance of the model with reference to the critical experimental investigation. LCF test specimens of the AlSi10Mg aluminium alloy have been fabricated through selective laser melting technology. The material shows strain-range dependent variation of modulus of elasticity under symmetric strain-controlled loading. The modulus of elasticity decreases with increasing strain amplitude. Stress-strain responses have been critically examined under multistep uniaxial ratcheting in the LCF regime with incremental mean stress and stress amplitude. Damage calculation considering ratcheting and LCF mechanisms as independent gives unconservative predictions. The linear damage accumulation rule taking the largest contribution of both is bringing much more accurate estimates. The proposed model incorporates effects of mean stress and stress amplitude under uniaxial multistep ratcheting in the LCF regime. All fatigue tests in the LCF regime have been simulated using the proposed improved model. Evolution of strain-range dependent elastic modulus has been incorporated in the formulation of the improved model through the memory history dependent parameter. The ratcheting parameter is newly formulated in this present work to account for the effects of accumulated mean plastic strain on the opening of stress strain hysteresis loops that results in a better prediction of the behaviour of cyclic plastic deformation. The proposed model has been validated by comparing simulated results with experimental observations and reference published simulation results.

Among the various surface modification processes, the hot-dip aluminizing process has increasingly evoked considerable attention. This method has proved to be commercially cost-effective and technically better than galvanizing. In contrast to hot-dip aluminized steel components, galvanized components cannot be used in service conditions at elevated temperatures. During the last few years, intensive research by researchers has yielded new insights into metallurgical aspects of aluminized coating in as-dipped and annealed condition. The present review gives a bird’s eye view of the hot-dip aluminizing process, from the early years of its inception to the current research on aspects of the aluminized coating. The progress of research on thermodynamic studies, phase equilibria, phase identification, and their crystallographic features have been traced in this attempt. This review is not restricted to briefing the research performed so far but also points out several issues of discrepancies among the results of the published literature. Special emphasis has been given to the phase development in the coating during annealing and the increasing horizon of application of hot-dip aluminizing to alloy steels in hot stamped conditions. Reference has also been made to state-of-the-art topics embracing the current research on computer simulation software and sophisticated experimental techniques. However, lower surface hardness and economy restrict the wide application of the hot-dipping process.

In the present work, a cyclic plasticity model based on Ohno-Wang kinematic hardening rule and Tanaka nonproportionality parameter, is proposed to simulate the cyclic stress strain response of three materials. The proposed model has been validated with respect to reported test results on two grades of steel (SA 333 Gr. 6 and E355) and one grade of austenitic stainless steel (X5CrNi18-10) under asynchronous axial-torsion loading conditions with a wide range of frequency ratios. The proposed model resulted in a comparable assessment of axial and shear stress-strain response with respect to the test loops for all three materials.

In this work, a prominent cyclic plasticity model based on modified AbdelKarim-Ohno kinematic hardening rule and Calloch isotropic hardening is implemented and validated w.r.t. test results of low C-Mn steel. In reference to the shortcomings of the model, an improved model based on modified Ohno-Wang and Tanaka non -proportionality parameter is introduced. Since the precise assessment of stress-strain response is an essential precondition for carrying out fatigue life analysis, therefore hysteresis loop responses under various multiaxial LCF loading having different strain paths are compared. The simulation result with the proposed model resulted in improved assessment for non-proportional strain paths.

In this present work, a damage-coupled cyclic plasticity model has been developed for more accurate ratcheting–fatigue life estimation under strain and stress controlled ratcheting. Ratcheting–fatigue damage behavior under uniaxial multistep strain-controlled ratcheting shows that the incremental mean ratcheting strain deteriorates the elastic slopes cycle by cycle, by means of ratcheting damage. Severe ratcheting strain accumulation rate has been observed in tertiary region under uniaxial stress controlled ratcheting. The proposed damage-coupled model has been constructed which incorporates both fatigue damage and damaging effect of the accumulated mean plastic strain. The proposed model incorporates a critical fatigue damage parameter which can predict effects of early fatigue crack nucleation due to combined ratcheting and fatigue damages. The performance of the proposed damage-coupled model has been investigated in the present study based on the critical fatigue damage parameter. The proposed model is calibrated on experimental data of SA333 Gr. 6 carbon steel and SA508 Gr. 3 steel. The proposed formulations have been applied in user material subroutine UMAT of finite element software, ABAQUS. The proposed model has been validated by comparing predicted ratcheting behavior with experiments for the two different steels. All the predicted number of cycles to failure are located within 0.5 times error band. The proposed damage-coupled model has demonstrated excellent capabilities of predicting ratcheting–fatigue life under cyclic loading with ratcheting damage.

The aim and objective of the present experimental work is to find out the predicted value of Radial over cut (ROC) while processing of Al7075 alloy through Equal Channel Angular Pressing (ECAP) with channel angel 90 degree and edge angle 20 degree with chosen process route C and alongwith suitable back pressure and subsequently machining that ECAP sample by Wire cut electric discharge machining (WEDM). Response Surface Methodology is applied in present study to predict the ROC in WEDM process for previously ECAP Al7075 alloy. Pulse off time (Toff), pulse on time (Ton), peak current (IP) and servo voltage (SV) are taken as input electrical parameters of process to study the ROC. The experiment was designed to perform based on Central Composite Design (CCD) method. After performing 31 experimental runs a mathematical model was being evolved for finding out the correlation and significance of electrical parameters on ROC. The coefficients were obtained by performing analysis through ANOVA at 95% confidence level. Observation shows that Ton and IP has got significant impact on ROC. The forecasted results based on mathematical model generated are found to be in a reasonably good degree of accuracy with the experimental result. Optimum value of radial overcut is obtained experimentally as 26.075 lm against Ton 7 ls, Toff 54 ls, for IP value 100 A and SV 25 V respectively. Copyright (C) 2022 Elsevier Ltd. All rights reserved.Selection and peer-review under responsibility of the scientific committee of the 3rd International Conference on Processing and Characterization of Materials 2021 (ICPCM 2021).

The conflicting traffic volume (CTV) is one of the crucial parameters for the estimation of U-turn capacity at a mid-block median opening (MBMO). Therefore, in this work, CTVs at MBMOs were estimated. A simple yet practical methodology was developed and a parameter called the spatiotemporal conflict factor was introduced. In order to estimate the spatial conflict factor, the entire carriageway width was divided into two zones – the spatial conflict zone and the spatial no-conflict zone. Spatial conflict factors were estimated by studying the placement characteristics of approaching through traffic and U-turning traffic. Subsequently, temporal conflict factors were estimated based on the no-conflict time gap and possible slowdown sections. The spatiotemporal conflict factors and the resulting CTVs were then calculated for MBMOs in six-lane and four-lane roads. The tangible outcome of this investigation is the ability to estimate the realistic capacity values of median openings, which will be beneficial for traffic planners in the efficient management of traffic for improved levels of service and safety.

In this work, a phenomenological unified model has been developed to characterize the cyclic plastic deformation response including hardening, softening and non-Masing characteristics of SA333 Gr.6 low C-Mn steel under various fatigue loading conditions. The unified proposed model embedded in the ABAQUS platform through user defined subroutine is based on the framework of the modified Ohno–Wang kinematic hardening rule and memory stress-dependent isotropic hardening formulation. The solid and tubular low cycle fatigue (LCF) specimens and also a pressurized primary heat transfer (PHT) straight nuclear pipe of this material under different loading conditions have been analyzed with this unified model using single set of material parameters derived from the experimental results of uniaxial LCF. The solid and tubular specimens have been loaded with uniaxial tensile-compressive low-cycle fatigue loading and multiaxial in-phase tension–torsion. For component-level analysis, three-point and four-point bending loads have been applied along with constant internal pressure in the PHT straight pipe. The predicted elastic–plastic response from the proposed model is correlated well with the corresponding experiment response under uniaxial tension–torsion and multiaxial in-phase tension–torsion loading. The major findings include the comparison of simulated hysteresis loop area, von Mises stress and variation of stress amplitude with the experiment response under strain-controlled LCF loading. The prediction of load-dependent hardening/softening and non-Masing characteristics using a unified proposed model is attributed to the continuous evolution of kinematic hardening and isotropic hardening utilizing the concept of memory stress. Further, the proposed model has improved the simulation of the circumferential strain ratcheting of the piping component under the combined three-point or four-point bending loads with constant pressure.

We were able to classify all 1-error correcting [5, 3] codes over GF(5) in paper [1] and [5, 2] ternary codes in paper [2]. Now, our focus is an equivalence based classification of error correcting linear codes of length 6 over GF(5). In paper [3], we investigated the equivalence of [6,3,4] codes of length 6 and dimension 3 over GF(4). In this paper we classify the [6,3,4] codes over GF(5). We explore the weight distribution of these codes as well as their duals.

Four different compositions of ZrB2-B4C composites (i.e., 5, 15, 20, 25 Wt. % of B4C) were fabricated by Spark Plasma Sintering Technique (SPS) at 2000 °C temperature. The composites were characterized by the evolution of physical and mechanical properties; X-Ray Diffraction (XRD) analysis was also done for phase analysis of the composites. The relative density values were obtained in the range of 96.14-97.78 % of all the composites. The addition of B4C in ZrB2 matrix led to an enhancement in hardness (15.38 GPa at 5 wt.% B4C to 20.49 GPa at 25 wt.% B4C measured at 1.0 kgf load) and fracture toughness (from 2.93 MPa-m0.5 at 5 wt.% B4C to 4.13 MPa-m0.5 at 25 wt.% B4C measured at 1.0 kgf load). The composite samples were processed by wire electrical discharge machining (WEDM) process with three different parameters set for the study of machining speed, surface roughness. The composite with 25 wt.% of B4C shows highest machining speed of 10.56 mm2/min. The average surface roughness (Ra) of the WEDM processed composite surfaces lies in the range of 1.26-5.64 μm.

Assessment of traffic safety is an essential study in transportation engineering. In a developing country like India, around 150,000 people die in road crashes every year. Furthermore, at uncontrolled median openings, the severity of road crashes is higher due to the presence of impatient U-turning road users who don't obey the rule of priority. Traditionally, road crash data have been used since long to analyze traffic safety. However, in developing countries, the main drawback of this conventional method is limited availability of accident data as very few accidents get reported. Moreover, the accuracy of these reported data is questionable. Therefore, now-a-days, various surrogate traffic safety measures like Post Encroachment Time (PET), and Time to Collision (TTC) are being used to examine the safety of road users. Among them, PET is regarded as the most consistent, and most widely used safety indicator. Therefore, in the present study, PET across different traffic volume levels has been determined. Videography data has been collected from selected median openings located on six-lane divided urban roads. PET values for different traffic volumes, and different category of vehicles have been analysed in detail. Further, the distribution of PET values across the full width of road has also been studied. Concept of critical speed is introduced which is compared with conflicting speed to assess unsafe conflicts and determine a critical PET. Finally, regression models have also been proposed with good levels of accuracy to determine the PET values for various category of vehicles travelling at different conflicting speeds.

Islands-Matrix-Dual-phase (I-M-DP) steel is received a great deal attention for better concern with the emissivity, fuel consumption and passengers safety. A number of deformation plasticity issues are yet to be fully understood. Complex deformation stages for various stain is predicted as the natural outfall of the plastic strain localization caused by the ill-assorted deformation between the martensite-island phase and the ferritic-matrix phase. Modeling is carried out both in macro level by bending under tension (BUT) for different roller radius/sheet thickness ratios to acquire strain and stress state deformation and micro scale by Representative Volume Element (RVE) according to element position. It can relate both the 2D, 3D micro and macro scale finite element based BUT model’s result of flow behavior. Systematically strain based severe deformation pattern arises from outfall of plastic strain localization and von Mises stress distribution in island-matrix steels are investigated on the microstructure by finite element method for ill-assorted deformation between phases.

In this research, microstructure and crystallographic features of different phases generated on interstitial free steel hot dipped in Al-6.9Si-1.4Mg alloy melt was examined. Bath temperature was 750 °C for 0.5, 1, 3 and 6 min dipping. A combined arrangement of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and electron backscatter diffraction was used for phase identification. Results indicated that aluminized layer comprised of outer Al-Si alloy top-coat, thin FeAl3 layer and a thick Fe2Al5 layer in contact with steel substrate. Ternary Fe-Al-Si intermetallic compounds of Al2FeSi (τ3) and Al3FeSi2 (τ4) were also identified. Elemental mapping, chemical composition analysis and in-depth composition profile of elements were done by electron probe microanalysis and glow discharge optical emission spectroscopy (GDOES). XRD study confirmed elemental silicon (Si) and magnesium (Mg) in the form of Mg2Si. SEM-EDS and GDOES studies confirm a sudden rise in Si at% at the top and in the intermetallic layer, which was attributed to the existence of Si-bearing phases or elemental pro-eutectic Si. The formability of the coated sheet was assessed by bending the samples at 180° to investigate the peeling-off of the outer coating layer from the steel surface.

Sintered boron carbide is an extremely hard, structural ceramic material and it is difficult to be machined with conventional techniques. To overcome the machining problem, the spark plasma sintered (SPS) monolithic boron carbide (B4C) was successfully machined by wire electrical discharge machining (WEDM) as the material is electrically conductive. The effects of five different machining parameters of WEDM were carefully observed to check their effect on the useful responses, namely machining speed and surface roughness (Ra) for cutting sintered B4C samples. A number of experimental operations were derived by using the concept of central composite design (CCD) and fuzzy logic was implemented to predict the response for a particular input parameter set. Also, a multi objective optimization was performed by fuzzy logic rule based multi performance characteristics indices technique (MPCI).