Stress-strain Characteristics Research Articles

Heat Dissipation and Thermal Stress-Strain Characteristics of an Impinging Jet Strengthened Rib Surface under a Laser Heat Source

Heat Dissipation and Thermal Stress-Strain Characteristics of an Impinging Jet Strengthened Rib Surface under a Laser Heat Source

Modeling of the accurate application of the Kernel Efficiency Method in the proportioning process of shield tunnel construction

Abstract The existing control strategies for subway construction struggle to address the challenges posed by the impact of large-diameter shield-driven underpass subway tunnels on soil settlement. In this paper, based on the mechanism of ground settlement of the shield tunnel under the KNX method, the influence of the underpass tunnel on the existing tunnel and its surrounding soil stress-strain characteristics is calculated by the Peck superposition method. The KNX method is optimized by optimizing the ratio of KNX slurry and the grouting pressure to control the existing tunnel and the ground settlement. The geotechnical general finite element analysis software is being introduced to conduct numerical simulation and engineering application experiments to verify its effectiveness. The results show that when the bonding force of the grouting material is 350Pa-s, the maximum value of the variation is 3.91mm, and the mobility is more suitable, which can effectively fill the void of the shield machine and reduce the settlement of the foundation. When the grouting pressure is 280kN/m2, the maximum contraction of the tunnel is 6.25mm, which can ensure the safety of the existing tunnel on the basis of the tunnel so that the actual settlement of the soil in the tunnel is minimized. Comprehensively, the optimization of the ratio of the KNP method in the control of the deformation characteristics of the soil and structures under the shield tunnel has effectiveness and can effectively provide theoretical and technical guidance for the construction of subway tunnels under the large-diameter shield under the subway.

Experimental and computational analysis of the structure-activity relationship of ionic gel electrolytes based on bistrifluoromethanesulfonimide salts for supercapacitors

Ionic gel (IG) electrolytes are emerging as promising components for the development of next-generation supercapacitors (SCs), offering benefits in terms of safety, cost-effectiveness, and flexibility. The ionic conductivity, stability, and mechanical properties of the gel electrolyte are relevant factors to be considered and the key to improving the performance of the SC. However, the structure–activity relationship between the internal structure of IGs and their SC properties is not fully understood. In the current study, the intuitive and regular structure–activity relationship between the structure and properties of IGs was revealed via combining computational simulation and experiment. In terms of conductivity, the ionic liquid (IL) ([EMIM][TFSI]) in the IG has a high self-diffusion coefficient calculated by molecular dynamics simulation (MDS), which is conductive to transfer and then improves the conductivity. The radial distribution function of the MDS shows that the larger the g(r) between the particles in the polymer network, the stronger the interaction. For stability, IGs based on [EMIM][TFSI] and [EOMIM][TFSI] ILs have higher density functional theory calculated binding energy, which is reflected in the excellent thermal stability and excellent capacitor cycle stability. Based on the internal pore size distribution and stress-strain characterization of the gel network ([ME3MePy][TFSI] and [BMIM][TFSI] as additives), the highly crosslinked aggregate network significantly reduces the internal mesoporous distribution and plays a leading role in improving the mechanical properties of the network. By using this strategy, it will be possible to design the ideal structure of the IG and achieve excellent performance.

Numerical and Experimental Analysis of Stress-Strain Characteristics in DP 600 and TRIP 400/700 Steel Sheets.

The body constitutes the largest proportion of the total vehicle weight. Recently, increasing efforts have been made towards reducing its weight and improving its crashworthiness. By reducing its weight, fuel consumption will be reduced, and this will also translate into lower CO2 emissions. In terms of safety, vehicle body components use high strength steel which can absorb a substantial amount of impact energy. The present study pays attention to DP 600 and TRIP 400/700 stress-strain characteristics at quasi-static strain rates. The stress-strain characteristics of absorption capacity, stiffness, and deformation resistance force were investigated experimentally by tensile tests, three-point bending tests, and numerical simulations. The results indicate the potential for increasing the absorption capacity, stiffness, and deformation resistance force of the vehicle body's deformable steel components. The present study verified the possibility of replacing physical testing with numerical simulation. A reasonably satisfactory agreement between the experimentally determined stress-strain characteristics and the numerical simulation was achieved, which can reduce the development time of deformable vehicle body components, reduce costs and optimize the selection of materials. The results extend the state of knowledge on the deformation characteristics of high-strength materials and contribute to the optimization of body components in terms of passive safety and weight.

RITZ METHOD IN THE DISCRETE APPROXIMATION OF DISPLACEMENTS FOR SLAB CALCULATION

Introduction: The FEM reduces the problem of structural analysis for various building structures to the formation and solution of a system of linear algebraic equations. For this purpose, there are techniques available for obtaining FE stiffness and flexibility matrices where the main structural deformation characteristics are taken into account. However, the FEM can also be considered as a special case of the Ritz method in the discrete approximation of the required functions. In the functional of full potential deformation energy with regard to the considered structure, all adopted stress-strain state characteristics are taken into account. Since it is difficult or impossible to find continuous approximation functions both in the classic version of the Ritz method and in the Bubnov–Galerkin method for some types of edge restraint in such building structures as beams, slabs, or shells, it is possible to use the Ritz method in the discrete approximation of the required functions (by analogy with the FEM). This paper presents a method of such calculations using slab calculations as an example. It is shown that, due to introducing some notations (operators), the process of finding the coefficients of the system of linear algebraic equations creates no difficulties and is easily programmable. The proposed method is not an alternative to the FEM, which is the most effective numerical method for the calculation of complex three-dimensional building structures. Purpose of the study: We aimed to create a method for calculating slabs by the Ritz method in the discrete approximation of the deflection function for edge restraint cases when it is difficult or impossible to find continuous approximation functions in the classic version of the Ritz method and the Bubnov–Galerkin method. Methods: Based on the application of the Ritz variational method in the discrete approximation of displacements for slab calculation, all the basic relations for rectangular finite elements with 12 degrees of freedom are obtained, and an algorithm for forming the coefficients of the system of linear algebraic equations is developed. Results: For the first time, the solution by the Ritz method in the discrete approximation of slab displacements is obtained for the case when two edges of the slab are rigidly restrained and other two edges are free. In this case, the correct solution of the above problem is possible only with the use of the proposed method and FEM. For the test problem, we performed a comparison of the results of the calculation using the proposed method with the results using the classic Ritz method, which showed their very close agreement. The accuracy of the obtained results was assessed.

Study on deformation behavior of Ti60 alloy based on multi-physics coupling

Titanium alloys are extensively employed in aerospace due to their superior performance, but their development is constrained by limited formability at room temperature, an electrically assisted forming (EAF) process emerges as a promising solution to reduce flow stress, improve formability, and accelerate material recrystallization. This study focuses on elucidating the interplay between pulse current, temperature, and flow stress in Ti60 alloy under combined electrical, thermal, and stress fields. To this end, electrically assisted tensile (EAT) tests were performed on Ti60 alloy using six different current densities. Currently, there is no unified theory for electro-plasticity in metal materials, and the absence of a suitable model hinders finite element simulation in EAF. The investigation encompasses four key areas: the impact of multi-physics coupling on temperature variations, the stress-strain curve characteristics, the microstructural analysis of tensile fractures, and the modification of the Johnson-Cook (MJC) model. Notably, temperature distribution proves more uniform across the width than the length. Tensile elongation initially rises and then falls with increasing current density, peaking at a critical current density (J=30 A/mm2). Higher current densities lead to a transition in fracture features, with deep, numerous dimples and tiny voids supplanting tearing ridges and facets. Despite this, brittle fracture remains the dominant mode, accompanied by granular oxide formation at J= 35, 40 A/mm2. The MJC model aligns closely with experimental outcomes, showing R and EAARE values of 92.7% and 7.15%, respectively. This model accurately predicts Ti60 alloy's deformation under multi-physics conditions, marking a significant advancement in integrating electro-plasticity into constitutive modeling.

Stress-strain characteristics of autoclaved aerated concrete masonry under varying displacement rates

Comprehending the impact of displacement rate on the mechanical properties of autoclaved aerated concrete (AAC) masonry is critical for predicting the response of structures to seismic and other natural dynamic loads. This study investigates the effect of varying displacement rates (0.1 mm/min, 1 mm/min, and 10 mm/min) on the mechanical properties of AAC masonry under uniaxial compression through systematic laboratory tests. Results indicate a substantial increase in elastic modulus (100 %) and compressive strength (200 %) as displacement rates rise from 0.1 mm/min to 10 mm/min. Finite element analysis using a micro-modelling strategy in Abaqus corroborates experimental findings, simulating crack propagation and identifying stress and strain distribution. The outcomes of this study would facilitate the accurate design and analysis of framed buildings infilled with AAC block masonry, especially under dynamic loading. These findings are expected to significantly contribute to the enhancement of structural engineering practices, enhancing the reliability and effectiveness of AAC block masonry for constructing resilient buildings.

Influencing Factors of Porosity and Strength of Plant-Growing Concrete.

A standardized preparation process is proposed in this study for achieving optimal strength and vegetative properties in vegetated concrete, using Yunnan red soil as a growth substrate for plants. The porosity of vegetated concrete is a crucial factor influencing plant growth, while compressive strength is a significant mechanical property. To assess the strength and porosity of vegetated concrete, different design porosities (22%, 24%, 26%, 28%) and cement-to-aggregate ratios (4, 5, 6, 7) were utilized in the preparation of vegetated concrete samples. The shell-making and static-pressure-molding methods were optimized for specimen preparation. Analyzing the stress-strain full curve characteristics of vegetation-type concrete under different influencing factors, an in-depth investigation into its failure mechanism was conducted. It was determined that the design porosity and cement content significantly impact the concrete's performance, particularly in terms of 30-day compressive strength and effective porosity. Furthermore, an increase in the fly ash ratio led to an increase in porosity and a decrease in compressive strength, providing a certain guidance for optimizing concrete performance. Comparative analysis through vegetation experiments revealed that black rye grass exhibited favorable growth adaptability compared to other grass species.

Analysis of Stress–Strain Characteristics and Signal Coherence of Low-Specific-Speed Impeller Based on Fluid–Structure Interaction

In this study, an analysis of a low-specific-speed pump is carried out based on the methods of one-way and two-way fluid–structure interactions (FSIs). This study analyzes the influence of FSIs on the internal flow field and external characteristics of the pump. Utilizing a two-way FSI, the signal coherence analysis method is employed to analyze the coherence of signals between the flow field and the structural field. Addressing the issue of a lack of a connection between the two signals, this study bridges a gap in the existing research. The results indicate that different interaction methods have certain influences on impeller stress and deformation. However, in both coupling modes, the maximum deformation and the maximum equivalent stress have the same distribution position. The head error obtained using the two-way coupling method is lower than that of the uncoupled results, which indicates that the two-way FSI calculation results are closer to the experimental results. The pressure pulsation signals at the interface of the impeller and volute exhibit strong coherence with the structural field signals. For low-specific-speed centrifugal pumps, establishing a clear connection between the flow field signals and structural field signals will help guide further optimization of their performance through design.

Experimental and Numerical Study on the Shear Performance of the Stone Panel–Panel Joint in Stone Cladding

The evaluation of the shear performance of stone panel–panel joints (SPPJs) in stone cladding has important engineering significance, as it plays a crucial role in stone cladding failure. The purpose of this paper is to analyze and predict the influence of the dimension and the Young’s modulus of sealant on the shear performance of SPPJs. Based on monotonic and cyclic loading tests, the effects of Young’s modulus and the dimension of sealant on the failure characteristics, stress–strain characteristics, stiffness degradation, and energy dissipation capacity of an SPPJs were investigated. According to finite element analysis, the strain distribution of an SPPJ under monotonic loading was analyzed for different sealant widths and number of sealant layers. The results indicate that the failure modes of SPPJs change with the variation of sealant amount. As the Young’s modulus of the sealant increases, the shear failure strength and shear yield strain of SPPJs increase. The increase in sealant thickness reduces the shear failure strength and stiffness of SPPJs. Based on the same shear strain, the increase in the sealant thickness enhances the cumulative energy consumption of SPPJs. The strain concentration zone of the specimens with two sealant layers in unilateral SPPJs becomes larger with the increase in sealant width.

Study on strength damage model considering resistivity and failure characteristics of the frozen soil–rock mixture under different loading rates

The strength damage and deformation failure of frozen soil–rock mixture (FSRM) often restrict the safety of the major engineering construction in cold areas or the spatial development of urban underground water-rich rock and soil masses. To investigate the uniaxial strength damage evolution and failure characteristics of FSRM under different loading rates (0.3, 0.6, 3, 6, 30, and 60 mm·min−1) in the quasi-static range, resistivity monitoring and image recognition technology were used to study the time-stress-volumetric strain-resistivity changes. The results indicate that the peak stress, peak strain, initial yield modulus, and tangential modulus of FSRM increase rapidly before increasing slowly as the loading rate increases, and there are critical loading rates and post-peak failure phenomenon. Three distinct types of failure modes, bulge failure, oblique shear failure, and fragmentation failure were observed at low (0.3–0.6 mm·min−1), medium (3–6 mm·min−1), and high loading rates (30–60 mm·min−1), respectively. The macroscopic failure of the FSRM at different loading rates arises from a combination of strain rate hardening of the strength and damage softening of the structure. To predict the stress-strain characteristics at various loading rates, a damage prediction model with a damage variable correction factor considering residual strength was employed based on the improved Duncan–Chang model and damage theory of electrical resistivity, and the predicted results were in good agreement with the experimental data.

Efficiency evaluation of a commercial superficial strengthening system applied to AAC-block walls under diagonal compression

The article presents the influence of a superficial strengthening system on the behaviour of AAC-block walls with thin bed joints and unfilled head joints. The strengthening system consisted of a high-strength fibreglass mesh applied to both wall surfaces with a mineral mortar reinforced with fibreglass. A series of strengthened and unstrengthened specimens was tested under diagonal compression according to ASTM E519-15 to determine their shear strength and stress-strain characteristics. The use of optical strain measurement made it possible to identify the failure mode for both types of the tested walls. The strengthening system changed the wall failure development, which was initiated by unfilled head joints in both cases. The application of the strengthening system on both wall surfaces improved the strength properties of the wall significantly. The load-bearing capacity of the specimens increased by nearly 90% and cracking of the walls occurred at loads about 50% higher compared to specimens with no superficial strengthening. The strengthened specimens exhibited a ductile behaviour after reaching the maximum bearing capacity. A simplified method for computing the cracking load and maximum load was also proposed, the results of which are consistent with the tests results.

Three-Dimensional Static and Dynamic Analyses of an Embedded Concrete-Face Rockfill Dam

Concrete-face rockfill dams have gradually become the preferred dam type in the engineering community. This study presents a hydropower station in China as a case study to introduce a new type of embedded concrete-face rockfill dam. The static and dynamic stress–strain characteristics of the proposed and conventional concrete-face rockfill dams were compared, and the optimal height of the embedded concrete body at the hydropower station was determined. The results indicate that, under static conditions, the embedded concrete body could reduce deformation upstream and downstream of the rockfill body, eliminate tensile stress along the concrete-face slab slope, reduce concrete-face slab deflection, and increase the maximum deflection area to 0.47 times the dam height. The inhibitory effect of the embedded concrete body on the stress and strain of the dam body became more evident as the size of the embedded body increased. Although the embedded concrete body did not enhance the dynamic and superposed static–dynamic stress states of the embedded concrete body and rockfill, the stress and strain increase in the dynamic state were within a controllable range. Through a sensitivity analysis and considering the terrain conditions and engineering cost of the hydropower station, the height of the embedded concrete body is recommended to be 0.4 times the dam height.

Study on damage and cracking of Mg-Gd-Y-Ag-Zr alloys during rolling based on experimental and finite element method

Edge cracking, a common issue encountered during the rolling of magnesium alloys, holds substantial importance in determining the success of subsequent finishing processes. It serves as a pivotal parameter for evaluating the formability of rolled plates. In this particular investigation, researchers concentrated on understanding the behavior of edge cracks within the solid solution magnesium alloy designated as Mg-10Gd-3Y-2Ag-0.4Zr (expressed in weight percentage as GWQ1032K). To support this analysis, one delved into the thermal rheological characteristics of the magnesium alloy and established a mathematical relationship connecting rheological stress, strain rate, and temperature. This served as the foundation for a constitutive model tailored to the alloy. Furthermore, practical rolling experiments were conducted to examine how reductions in thickness influenced the morphology of edge cracks in rolled plates. The study also explored shifts in stress–strain behavior and microstructural changes during the deformation process. The results highlighted the substantial impact of compression levels on the magnesium alloy’s anisotropic behavior, subsequently influencing the shape of the resultant plate and the stress–strain characteristics observed during deformation. Significantly, as the rolling reduction increased, a notable increase in heat generation due to the plastic deformation of the magnesium alloy plate was observed. This heightened heat played a key role in dynamic recrystallizationand and facilitating the formation of the brittle Mg5(RE, Ag) phase. Consequently, minimizing the generation of this brittle phase emerged as a critical factor in effectively managing and controlling edge cracks in the rolling process.

A Case Study for Stability Analysis of Toppling Slope under the Combined Action of Large Suspension Bridge Loads and Hydrodynamic Forces in a Large Reservoir Area

The foundation of a large river crossing bridge is often located on high and steep slopes in mountainous area, and the stability of the slope has a significant impact on the safety of the bridge. Not only the bridge load, but also the hydro-dynamical action in the reservoir area has a significant impact on the stability of the bank slope where the bridge foundation is located, especially for the toppling bank slope. This paper takes the stability of the toppling bank slope where the one major bridge foundation is located at on the Lancang River in China as an example. Through on-site exploration, drilling data and core conditions, and television images of the borehole, the geological structure of the on-site bank slope were conducted. Based on the development of the dumping body obtained from on-site exploration, corresponding indicators have been proposed from the perspectives of rock inclination, deformation, and rock quality to clarify the degree of dumping along the depth of the bank slope. The failure mechanism of the overturned bank slope under the action of a bridge was analyzed from a mechanical perspective. Numerical simulations were conducted using GeoStudio 2018:SEEP/W and FLAC3D 6.0 software to analyze the failure modes of bridge loads and hydrodynamic forces under different water levels and rainfall conditions. The seepage field characteristics, failure modes, and stability characteristics were analyzed from a two-dimensional perspective, while the displacement characteristics, plastic zone, and stress–strain characteristics were explored from a three-dimensional perspective, which revealed the evolution mode of overturned deformation under the action of bridge foundation loads. Finally, the stability of the wide slope was numerically calculated using the strength reduction method, and the stability calculation data was combined with the numerical simulation results to determine the optimal location of the bridge foundation.

Experimental Study on the Mechanical Properties of Reinforced Pervious Concrete

Pervious concrete (PC) has gained popularity as an environmentally friendly solution for mitigating the urban heat island effect and promoting sustainable construction. However, its lower compressive strength, attributed to its higher porosity required for permeability, poses challenges for withstanding heavy vehicle loads on pavements. Our study aims to improve the flexural strength of regular PC by adding advanced reinforcing materials like steel wire mesh or glass fiber mesh. This results in reinforced pervious concrete, referred to as RPC, which offers enhanced strength and durability. The primary objective of our research is to investigate the mechanical behavior of RPC, with a specific emphasis on essential design parameters such as PC elastic modulus, modulus of rupture, and stress–strain characteristics under both single and repeated loading conditions. Our findings reveal that the influence of repeated loading on the compressive strength and elastic modulus of PC pavement is negligible, as there are no significant differences observed between the two loading protocols. Notably, our statistical analysis indicates that the PC strength (fc′) averages around 15 MPa. Moreover, empirical formulas for the elastic modulus (Ec = 3072fc′) and modulus of rupture (fr = 0.86fc′) are derived from our research. Furthermore, our study establishes that the stress–strain behavior of PC closely aligns with the general concrete model proposed by a previous scholar, providing valuable insights into the material’s structural performance. These findings contribute to a better understanding of RPC’s mechanical properties and offer potential solutions for improving its suitability for heavier vehicular loads.

Impact of developed hybrid polypropylene fiber inclusion on the flexural performance of concrete beams reinforced with innovative hybrid bars

This paper investigates the impact of incorporating a hybrid combination of structural polypropylene fibers on the flexural behavior of concrete beams reinforced with steel, GFRP, and innovative hybrid bars. A new ductile hybrid bar with equivalent bilinear stress-strain characteristics has been developed to address steel corrosion and FRP ductility issues. Fourteen half-scale RC beams were fabricated and tested under four-point loading configuration to study the flexural response. The tensile reinforcement types (steel, GFRP, and hybrid), hybrid reinforcement ratios (0.85 %, 1.26 %, and 1.70 %), reinforcement hybridization schemes (hybrid-hybrid, hybrid-GFRP, and GFRP-steel), and hybrid fiber ratio (0.0 %, 1.0 %, and 2.0 %) are the major parameters studied. The test results were recorded and analyzed in terms of mid-span deflection, cracking load, flexural capacity, and failure mechanism. The results demonstrated that the addition of hybrid fibers and using hybrid bars significantly improved the peak strength, ductility index, and bending stiffness. Moreover, the hybrid-reinforced concrete beams exhibit large inelastic deformations similar to steel-reinforced concrete beams. The inclusion of hybrid fibers improves the post-peak response of the tested beam due to fiber bridging capabilities. For design purposes, a simplified formula proposed by ACI 544 for predicting the nominal flexural capacity of hybrid fiber concrete beams reinforced with hybrid bars was presented, compared with experimental results and validated with 44 specimens from other studies. The predicted and test results were in good agreement with a standard deviation of 0.12. Additionally, 3D nonlinear finite element analysis was developed to validate the test results, demonstrating reasonable accuracy in predicting the flexural behavior of the beams.

Poly(Siloxane–Propylene Oxide–Urethane–Ureas) Based on Cycloaliphatic Diisocyanates: Synthesis and Properties

New network poly(siloxane–propylene oxide–urethane–ureas) based on α,ω-bis[(3-aminopropyl)diethoxy]oligodimethylsiloxanes, oligo(propylene oxide), and cycloaliphatic diisocyanates are synthesized. The resulting polymers are studied by differential scanning calorimetry and thermogravimetric analysis; their stress–strain characteristics are elucidated. These polymers are found to feature microphase separation and, consequently, two glass transition temperatures, defined by the chemical structures of the microphases. It is shown that an increase in the molecular weight and mass content of siloxane blocks leads to a decrease in the elastic modulus and tensile strength.

UV Radiation Effect in New Materials Developed for the Construction of Beehives.

In recent decades, there has been an increasing focus on the alarming decline in global bee populations, given their critical ecological contributions to natural pollination and biodiversity. This decline, marked by a substantial reduction in bee colonies in forested areas, has serious implications for sustainable beekeeping practices and poses a broader risk to ecological well-being. Addressing these pressing issues requires innovative solutions, one of which involves the development and fabrication of beehives crafted from composite materials that are ecologically compatible with bee biology. Importantly, these materials should also exhibit a high resistance to environmental factors, such as ultraviolet (UV) radiation, in order to maintain their mechanical integrity and longevity. To investigate this, we conducted accelerated UV degradation tests on a variety of composite materials to rapidly assess their susceptibility to UV-induced changes. High-density polyethylene (HDPE) served as the matrix material and was reinforced with natural fibers, specifically fique fibers (Furcraea bedinghausii), banana fibers, and goose feathers. Our findings indicate that UV radiation exposure results in a noticeable reduction in the tensile strength of these materials. For example, wood composites experienced a 48% decline in tensile strength over a 60-day period, a rate of deterioration notably higher than that of other tested composite materials. Conversely, HDPE composites fortified with banana fibers initially demonstrated tensile strengths exceeding 9 MPa and 10 MPa. Although these values gradually decreased over the observation period, the composites still displayed favorable stress-strain characteristics. This research underscores the substantial influence of UV radiation on the longevity and efficacy of beehive materials, which in turn affects the durability of natural wood hives exposed to these environmental factors. The resultant increased maintenance and replacement costs for beekeepers further emphasize the need for judicious material selection in beehive construction and point to the viability of the composite materials examined in this study.

Use of hardness, PIP and tensile testing to obtain stress-strain relationships for metals

Both hardness testing and Profilometry-based Indentation Plastometry (PIP) can be used to obtain features of (tensile) stress-strain curves. The two tests are superficially similar, involving penetration (under a known load) of an indenter into the flat surface of a sample, followed by measurement of dimensional characteristics of the residual indent. The associated data handling procedures, however, are very different in the two types of test. Hardness numbers, which are commonly based on measurement of the lateral extent or depth of the indent, essentially give a semi-quantitative indication of the resistance to plastic deformation: going beyond this to infer features of the (nominal) stress-strain curve – notably the yield stress (YS) and Ultimate Tensile Stress (UTS) – can only be done via empirical correlations (often restricted to certain types of alloy). PIP testing, on the other hand, involves measurement of the complete indent profile, followed by (automated) iterative FEM modelling of the indentation, allowing the complete (true) stress-strain curve to be obtained. This paper covers application of both approaches to 12 different alloys, with inferred stress-strain characteristics being compared with those from tensile testing. Insights are provided relating to the very different levels of detail and reliability offered by the two procedures.