Stress Analysis Research Articles

Micro-mechanical analysis of residual stresses in cohesive-frictional particulate materials under moving surface loads

Micro-mechanical analysis of residual stresses in cohesive-frictional particulate materials under moving surface loads

Electromagnetic Design Optimization Integrated with Mechanical Stress Analysis of PM-Assisted Synchronous Reluctance Machine Topologies Enabled with a Blend of Magnets

Permanent Magnet-Assisted Synchronous Reluctance Machines (PMASynRM) provide a low-cost alternative to Surface PM Machines due to the use of relatively lower grades of rare-earth (RE) or RE-free magnets, as the performance degradation due to weaker magnets is compensated by the presence of reluctance torque. However, the weaker magnets suffer from a high risk of demagnetization, leading to unreliable motor operation. Using a blend of RE and RE-free magnets has the potential to overcome this issue. This paper proposes to blend different grades of various rare-earth (RE) and rare-earth-free (RE-free) magnets in six different combinations and utilizes them in two-layer and three-layer U-shaped PMASynRM topologies with both eight-pole and six-pole variations. The rotor of the various designs is then optimized using a differential evolution (DE) based optimization algorithm to obtain low-cost designs with reduced RE magnet volume and minimum demagnetization risk. The optimization of each design is also integrated with the evaluation of mechanical stresses in the rotor laminations so as to maintain the stresses below the material yield strength. Furthermore, the various performance metrics, such as toque–speed/power–speed characteristics, demagnetization, and efficiency maps, are evaluated for each of the optimized and mechanically feasible designs. A quantitative comparison of the various optimized designs is also obtained to highlight the various trade-offs. The results indicate the feasibility of meeting the baseline torque requirement across the entire speed range, even with a 100% reduction in RE magnet volume and less than 5% demagnetization risk, while achieving a cost reduction exceeding 50%. Moreover, the two-layer, eight-pole designs exhibit relatively higher performance, whereas the three-layer, eight-pole designs are found to be the most economical option.

Understanding Research Dynamics in Job Stress

The objective of this analysis is to conduct a bibliometric analysis to map the research on work stress. This will be done by employing quantitative methods such as network, overlay, and density cluster models to analyze the research on work stress over a span of 11 years. Data are extracted from the scientific literature in the Science Direct database using the keyword "job stress," in which a total of 180 relevant articles were identified. These articles were analyzed using algorithms in Vosviewer to identify common topics in stress research. The analysis revealed that work-related stress studies frequently discuss 39 key topics, as determined by researchers. Through bibliometric analysis utilizing a network visualization model, it has been determined that there are six recurring clusters of keywords. The initial cluster, highlighted in red, comprises a total of 11 keywords. The terms "job stress" and "job satisfaction" have been the primary focus of research in the field of job stress analysis from 2013 to 2023. In response to the analysis of overlay visualization, the keyword "job stress" has been frequently examined from the past to the present. According to the density visualization analysis, the keywords "job stress" and "job satisfaction" exhibit the most intense and prominent colors, suggesting that numerous researchers have conducted studies on job stress.

A comprehensive methodology to estimate the fatigue life of S-shaped integral squeeze film damper

The Integral Squeeze Film Damper (ISFD) finds widespread application in various rotating machinery, such as gas turbines, turbochargers, and high-speed rotors, to dampen vibrations and improve operational stability. This study presents a comprehensive methodology to predict the fatigue life of an Integral Squeeze Film Damper (ISFD) by combining Low Cycle Fatigue (LCF), High Cycle Fatigue (HCF) test, and Finite Element (FE) simulations. An S-shaped spring specimen is designed and tested under high-cycle fatigue loading to develop the stress amplitude versus the number of the cycles curve. LCF tests are performed to obtain fatigue parameters, and a Chaboche kinematic hardening model is employed for cyclic plasticity FE simulations. FE analysis of the ISFD is conducted to establish its dynamic characteristics, aiding in identifying critical locations based on maximum von Mises stress. The integration of local stress–strain states from FE simulations with experimental fatigue parameters is carried out to predict fatigue life of ISFD. The validity of the methodology is confirmed through experimental and stress analyses, providing valuable insights for optimizing the fatigue performance of ISFD components.

Three-dimensional nonlinear stress analysis of functionally graded shells subjected to displacement-dependent loads

The nonlinear geometrically exact (GeX) hybrid-mixed four-node solid-shell element under non-conservative loading, developed in the companion paper, is here extended to the stress analysis of functionally graded material (FGM) shells. The term GeX means that the middle surface is described by analytical functions, including spline functions, and, therefore, the coefficients of the first and second fundamental forms can be taken exactly at element nodes. The FGM solid-shell element formulation is based on the choice of N sampling surfaces (SaS) parallel to the middle surface and located at Chebyshev polynomial nodes within the shell as well as on the outer surfaces, to introduce the displacements of these surfaces as basic unknowns. The use of Lagrange polynomials of degree N–1 in the distributions of displacements, strains, stresses, and elastic coefficients through the thickness of the shell leads to an efficient 3N-parameter shell formulation. To develop the FGM four-node solid-shell element based on the hybrid-mixed method, in which strains and stresses are utilized as primary variables, the Hu-Washizu variational principle is applied. Due to the analytical integration used to evaluate the tangent stiffness matrix, the developed FGM solid-shell element subjected to displacement-dependent loads shows superior performance in the case of coarse meshes and allows the use of only one load step in most of the considered benchmark problems. It has been established that the difference between the second Piola-Kirchhoff and Cauchy stress tensors in non-conservative problems for FGM shells undergoing moderately large strains can be significant.

Multi-objective optimization and correlation development of HPD-type perforated fins based on fluid–structure interaction analysis

In this study, in combination with the flow behavior of HPD-type fins, an HPD-type perforated fin is proposed, which reduces the flow resistance by an average of 55.9% and improves the comprehensive performance by an average of 22.3%. Subsequently, the thermal–hydraulic performance and stress analysis of HPD-type perforated fins are numerically investigated based on fluid–structure interaction analysis. The findings indicate that the performance of HPD-type perforated fins is highly influenced by the fin width Fw. Moreover, the correlations were established using the RSM concerning the j, f-factor, and the maximum stress, with maximum prediction errors of 8.9%, 19.1%, and 5.8%, respectively. Ultimately, the optimized parameter combination for HPD-type perforated fins was determined through GRA, considering maximum JF-factor and minimal maximum stress as the optimization objectives. The outcomes revealed a notable enhancement in the JF-factor by 96.4% and a concurrent reduction in maximum stress by 3.7% under identical conditions. In conclusion, perforating HPD-type fins proves to be an effective strategy for enhancing both thermal–hydraulic performance and stress distribution.

Towards automated characterisation of fatigue damage in composites using thermoelastic stress analysis

Composite materials demonstrate complicated fatigue behaviour due to their microstructure and the varied types of defects that can occur during loading. This necessitates experimentation to determine their performance under loading. In this study an algorithm is introduced for identifying and categorising different defects forming during fatigue tests. Thermoelastic stress analysis was used to obtain high spatial and temporal resolution stress information from the surface of notched composite specimens. Specimens with three different geometries were loaded in tension–tension fatigue to failure. An algorithm was used to identify when and where matrix cracking and delaminations formed within the specimens as well as quantify how this changed over time. By improving how damage events are identified and characterised, the algorithm reduces the amount of time needed to process experimental fatigue data and helps to provide greater understanding of fatigue processes in new materials from early small-scale cracking all the way to final failure.

SR-M−GAN: A generative model for high-fidelity stress fields prediction of the composite bolted joints

Predicting the stress fields induced by composite bolted joints constitutes a valuable research endeavor aimed at enhancing the structural integrity of equipment in the aerospace and maritime fields. The stress field characteristics of composite bolted joints may undergo changes due to potential mechanical behaviors, such as damage, constitutive relationships and so on, which exhibit complexity and pose challenges for prediction. Nevertheless, modeling the intricate stress field distribution directly from experimental data poses a formidable challenge, necessitating a substantial investment in materials and resources. Traditional finite element numerical methods have the capability to model the distribution of the stress fields. However, to obtain a high-fidelity solution of this distribution, it is imperative to generate a fine-grid mesh and allocate the significant computational resources. The incorporation of computational techniques in coarse −grid would enhance the efficiency of computations, but these approaches compromise the accuracy of the calculations. In this paper, an innovative deep learning framework is introduced. The network named as the SR-M−GAN is drew inspiration from the conditional generative adversarial network (cGAN) used in the image super-resolution. The primary aim of SR-M−GAN is to mitigate the intrinsic trade-off between result fidelity and computational complexity. The model proposed in this paper effectively reconstructs high-fidelity stress field data from calculations on coarse grids and exhibits excellent reconstruction metrics. Simultaneously, the model only incurs additional computational costs during the deployment of the network model and training. When compared to experimental data, the model continues to demonstrate superior performance in both accuracy and computational efficiency. Therefore, this method offers a high-fidelity data augmentation approach for stress analysis in composite bolted joints, laying the groundwork for large-scale analysis of stress field characteristics in composite bolted joints.

Structural integrity and corrosion behavior assessment of the dissimilar gas tungsten arc welded joint of sDSS 2507/ IN625 superalloy

This study investigates the effect of filler materials on the structural integrity of dissimilar welded joints (sDSS 2507/IN625) employed in marine subsea manifold applications. Multi-pass gas tungsten arc welding (GTAW) using ER2594 and ERNiCrMo-3 fillers investigates microstructure evolution, solidification mechanisms, mechanical characteristics, residual stresses, and corrosion behavior. Optical and scanning electron microscopy revealed an unmixed zone (peninsula/island-shaped) at the weld interface and weld zone (WZ) in both filler weldments. Segregation of Mo, Nb, and Ni was observed in the interdendritic region of ERNiCrMo-3 filler WZ, whereas the skeletal ferrite matrix of ER2594 filler WZ revealed the existence of the Laves phase (Fe2Nb form). Electron beam scattered diffraction (EBSD) investigation showed austenitic solidification for ERNiCrMo-3 and fully ferritic solidification for ER2594 with distinct dendrite formations. Inhomogeneity has been observed in microhardness maps, with ER2594 and ERNiCrMo-3 WZ averaging 310 ± 7 Hv0.5 and 270 ± 10 Hv0.5, respectively. ERNiCrMo-3 (165 ± 5 J and 180 ± 3 J) and ER2594 (100 ± 3 J and 110 ± 6 J) fillers exhibited distinct effects on toughness in the weld cap and root due to laves phase precipitation. Additionally, ER2594 (750 ± 6 MPa) and ERNiCrMo-3 (790 ± 7 MPa) fillers exhibited lower tensile strength than base metals. The structural integrity of WZ can be better understood by residual stress analysis, which showed compressive cap pass and tensile root pass residual stresses for both fillers. In a 3.5 wt% NaCl solution, both fillers exhibited outstanding corrosion resistance in marine conditions. These findings improve subsea manifold structure integrity and performance in corrosive marine environments.

Network analysis of posttraumatic stress and posttraumatic growth symptoms among women in subsequent pregnancies following pregnancy loss

BackgroundPregnant women who have undergone pregnancy loss often display both posttraumatic stress (PTS) and posttraumatic growth (PTG). However, the precise relationship and structure of symptomatic levels of PTS and PTG have not been well understood. This study aimed to assess the associations between PTS and PTG symptoms in women during subsequent pregnancies following a previous pregnancy loss.MethodsA total of 406 pregnant women with a history of pregnancy loss were included in this study. The Impact of Events Scale-6 (IES-6) and the Posttraumatic Growth Inventory Short Form (PTGI-SF) were used to assess symptoms of PTS and PTG, respectively. The Graphical Gaussian Model was employed to estimate the network model. Central symptoms and bridge symptoms were identified based on “expected influence” and “bridge expected influence” indices, respectively. The stability and accuracy of the network were examined using the case-dropping procedure and nonparametric bootstrapped procedure.ResultsThe network analysis identified PTG3 (“Ability to do better things”) as the most central symptom, followed by PTS3 (“Avoidance of thoughts”) and PTG6 (“New path for life”) in the sample. Additionally, PTS3 (“Avoidance of thoughts”) and PTG9 (“Perception of greater personal strength”) were bridge symptoms linking PTS and PTG clusters. The network structure was robust in stability and accuracy tests.ConclusionsInterventions targeting the central symptoms identified, along with key bridge symptoms, have the potential to alleviate the severity of PTS experienced by women with a history of pregnancy loss and promote their personal growth.

Analysis and verification of electrodynamic force, thermal stress and current sharing for CRAFT converter structure design

Abstract In the design realm of fusion power supplies, structural component plays a pivotal role in ensuring the safety of fusion device. To verify the reliability of converter structure design in Comprehensive Research Facility for Fusion Technology (CRAFT), the meticulous analysis of the converter's dynamic impact is carefully analyzed based on the worst fault current (400 kA), firstly. Subsequently, the thermal stress analysis based on maximum allowable steady-state temperature is finished, and the equivalent thermal stress, thermal deformation, maximum shear stress of single bridge arm and whole converter are studied. Furthermore, a simple research method of current sharing characteristics of bridge arm with multi-thyristor parallel connection is proposed by combination Simplorer with Q3D in ANSYS. The results show that the current sharing characteristics is great. Finally, the structural design has been meticulously tailored to meet the established requirements.

Simplified Model Study of Autoclaved Aerated Concrete Masonry Flexible Connection Infilled Frames with Basalt Fiber Grating Strips

Infilled walls and frames typically employ closely spaced rigid connection, which, under seismic actions, can lead to adverse effects such as amplified seismic responses, overall torsion, and the formation of weak layers in the structure. Flexible connection isolating the infilled walls from the frames can effectively mitigate the adverse effects of rigid connections. In order to reduce the structural mass and seismic impacts, Autoclaved Aerated Concrete (AAC) masonry flexible connection infilled walls have been widely researched. However, most AAC masonry flexible connection infilled walls require complex process operations for AAC blocks, which is not conducive to practical applications in engineering. Therefore, an AAC flexible connection infilled wall with Basalt Fiber Grating (BFG) strips instead of steel bars, with simplified process operations, has been proposed. Existing finite element models for BFG strip-reinforced AAC masonry flexible connection infilled walls employ solid elements, which are difficult to apply to large-scale structural simulations; moreover, existing simplified models for flexible connection infilled walls cannot simulate out-of-plane loading. In this paper, based on homogenization methods, using simplified elements to simulate components, a simplified model for the BFG strip-reinforced AAC masonry flexible connection infilled frame is proposed. Utilizing this model, stress analyses under both in-plane and out-of-plane loading are conducted and compared with corresponding experimental results. The results indicate that the in-plane simplified model (ISM) fits well with the experimental results in terms of hysteresis curves, with similar relationships between stiffness degradation and strength attenuation. The displacement force curve of the out-of-plane simplified model (OSM) before reaching the peak load is in good agreement with the experimental results. The maximum plastic range of OSM is 5% smaller than the test results, and it can be considered that the plastic ranges of the two are comparable, manifesting the models’ capability to adequately manifest arching behavior. The simplified model enables simulation of out-of-plane loading and provides a new approach for modeling large-scale frame structures with flexible connection infilled wall.

Tensile assessment of woven CFRP using finite element method: A benchmarking and preliminary study for thin-walled structure application

Abstract Carbon-fiber-reinforced polymers (CFRPs) are a composite material popular for thin-walled structure applications because of their advantages over other materials. In this study, numerical simulation analysis based on the finite-element method to identify the tensile behavior of CFRP woven material has been carried out. The method used has been verified and validated using a benchmarking procedure with the results of previous research. Errors in the simulation results are less than 10%, indicating a valid method that can be used for further research. The stress–strain distribution of each layer, the effect of ply orientation on tensile strength, the comparison of failure criteria used, and the comparison of several types of reinforcements often used have been investigated. The results showed that the characteristics of each inner layer received tensile loading visualized in the form of stress strains. Choosing the right layer angle on CFRP woven can affect the performance and strength of the material. Failure criteria that are appropriate to specific application conditions are important. Puck criteria can be used for simple applications, which require only the analysis of the main stresses in the material. Tsai–Hill and Tsai–Wu criteria can provide more accurate predictions and are better suited for loading conditions and more complex material types. Carbon fiber has better characteristics when compared to S-glass and E-glass.

Sub-filter-scale shear stress analysis in hypersonic turbulent Couette flow

Direct numerical simulations of hypersonic turbulent Couette flows are performed for top-wall Mach numbers of 6, 7 and 8, inspired by non-reactive high-enthalpy wind tunnel free-stream conditions, with the goal of analysing the physical processes driving the sub-filter-scale (SFS) stresses to inform development of large-eddy simulation techniques for hypersonic wall-bounded flows. Semi-local scaling laws collapse mean profiles and second-order turbulent statistics well, in spite of the strong wall-normal gradients of temperature and density. On the other hand, the SFS shear stresses exhibit an unexpected profile characterized by a region of pronounced shear stress deficit, which becomes more pronounced for higher Mach numbers. Instantaneous visualizations suggest that the SFS shear stress deficit is induced by the counter-gradient resolved momentum transport driven by residual velocity motions at the interface between high-density low-speed streaks being ejected away from the wall, and low-density high-speed ones replacing the displaced fluid, qualifying this as a compressibility effect. It is shown that the SFS shear stresses are primarily driven by second-order interactions between residual velocities, in spite of their triply nonlinear nature. This, in turn, motivated a statistical quadrant analysis revealing the presence of a SFS shear stress deficit, that is, SFS processes driving momentum transport of the resolved field towards the top wall. Additionally, higher-Reynolds-number simulations reveal that there is an upper limit of spatial filter widths to resolve large-scale structures, and such deficit is observable at any Reynolds number when a reasonable spatial filter is applied.

Fan-out panel-level package warpage and reliability analyses considering the fabrication process

With the continuous advancement of IC packaging technology, 3D and 2.5D packaging systems have emerged as the prevailing trends. The advantages of large area and high I/O density have made fan-out panel-level packaging (FOPLP) been considered as one of the best package types for 3D and 2.5D packaging applications. The discussions about FOPLP have been popular recently. Warpage and reliability of FOPLP are the main concerns of packaging engineers. However, it was found that warpage and reliability of FOPLP are strongly related to the fabrication process but not many research works have been published. Thus, reliability analysis procedure considering the residual stress of fabrication process was proposed in this paper to observe warpage and stress distribution during fabrication process. Then, this research procedure facilitates subsequent fatigue life calculations and predicts reliability of the package.First, the thermal stresses and warpage of the redistribution layer-first (RDL-first) process were conducted for an entire panel. Next, warpage and thermal stress analyses were conducted for a strip encapsulated with an epoxy molding compound (EMC) during compression molding. Then, a reliability analysis was conducted with an IC unit and incorporated the consideration of the residual stress induced during the fabrication processes.The compression molding analysis utilized the pressure–volume–temperature–cure (P–V–T–C) model to account for both the volume shrinkage caused by a thermal mismatch and the chemical shrinkage. Furthermore, dual shift factor model was used to model the viscoelastic behavior of EMC in this study during PMC analysis effectively.An observation of the stress distribution for an IC unit revealed that the maximum stress position was at the solder ball near the periphery, with a stress value of 147.309 MPa. The fatigue life calculated using the modified Coffin–Manson fatigue model was 417 cycles.

Dislocation slip mechanism and prediction method during the ultra-precision grinding process of monocrystalline silicon

Prediction of dislocation depth during ultra-precision grinding of monocrystalline silicon is a major challenge. To provide atomistic perspective, a single grain scratching molecular dynamics (MD) model of monocrystalline silicon is established to analyze the initiation and slip mechanism of dislocation. The simulation results show that the initiation of dislocations depends on the normal scratching force, and the dislocation length decreases with the decrease of scratching force and the increase of scratching velocity. Besides, the active slip system was identified by calculating Schmid factor, and the slip stress τ(111)[110],p (i.e. Peierls stress) of 2 GPa for ±1/2[110] dislocation on (1 1‾ 1) plane was obtained. Furthermore, a prediction model for dislocation depth was established based on the analysis of shear stress τ(111)[110]. Finally, a set of nano-scratch experiments were carried out, and the depth and slip direction of dislocation that close to the predicted were obtained by TEM method. This study provides a new method for predicting and controlling dislocation damage of monocrystalline silicon during ultra-precision grinding.

Psychological Stress Analysis to Evaluate the Effects of Transcranial Magnetic Stimulation on Mood Regulation and Quality of Life in Patients with Bipolar Disorder.

To explore the impact of transcranial magnetic stimulation on emotion regulation and quality of life in patients with bipolar disorder (BD) and to evaluate the effectiveness of the mental stress analyzer. Patients with BD admitted to our hospital from August 2022 to August 2023 were retrospectively selected. For the present study, 60 patients who received drug therapy served as the control group, and the other 60 patients who received repeated transcranial stimulation on this basis served as the observation group. The heart rate variability (HRV) of the two groups of patients was detected by a mental stress analyzer/HRV analysis system. Hamilton Depression Rating Scale (HAMD), Self-Rating Anxiety Scale (SAS), and Self-Rating Depression Scale (SDS) were used to evaluate the mental state of the two groups of patients. The quality of life of the two groups was assessed using the Comprehensive Quality of Life Questionnaire 74 (GQOLI-74). Clinical effectiveness global rating scale-illness severity (CGI-SI) was used to evaluate the clinical symptoms of the two groups of patients, and the incidence of adverse reactions was calculated. In comparison to the control group, the high-frequency power (HF) of the patients demonstrated an elevation in the observation group, and the low-frequency power (LF) and LF/HF were significantly reduced (p < 0.05). The standard deviation of NN intervals (SDNN), standard deviation of all five-minute NN intervals (SDANN), root mean square of successive differences (rMSSD), and percent RR intervals with a difference in duration higher than 50 ms (PNN50) of patients in the observation group showed a notable increase compared to the control group (p < 0.05). Compared with the control group, the HAMD, SAS, and SDS scores of the patients in the observation group demonstrated a substantial decline relative to the control group (p < 0.05). In contrast to the control group, there was a significant increase in the overall clinical effectiveness rate among patients in the observation group, and the incidence of adverse reactions was significantly reduced (p < 0.05). Repetitive transcranial magnetic stimulation (rTMS) has significant clinical effects in treating BD and can effectively improve patients' anxiety, suppress emotions, and regulate patients' emotions. At the same time, rTMS has high safety and little impact on the balance of patients' autonomic nervous function, reduces the incidence of adverse reactions, accelerates the patient's recovery process, and is suitable for clinical promotion.

Erratum to: Residual Stress Analysis of Additive Manufactured A356.2 Aluminum Alloys using X-Ray Diffraction Methods

Erratum to: Residual Stress Analysis of Additive Manufactured A356.2 Aluminum Alloys using X-Ray Diffraction Methods

Anti‐plane stress analysis for V‐notch in a piezomagnetic half space under SH wave

AbstractIn this paper, the anti‐plane stress analysis of a V‐notch with complex boundary conditions in a piezomagnetic half space is studied. Firstly, SH wave is considered as an external load acting on piezomagnetic half space, on the basis of repeated image superposition, the analytical expression of scattering wave is conducted, which satisfies the boundary conditions on the boundary of the half space. Then, the analytical expression of standing wave is established, which satisfies the stress free and magnetic insulation conditions on the boundaries of V‐notch by the fractional Bessel function expansion method and Graf addition theorem. Finally, Green's function method is applied, the half space is divided into two parts along the vertical interface, a pair of in‐plane magnetic field and out‐plane forces are applied on the vertical interface, and the first kind of Fredholm integral equations are set up and solved by applying orthogonal function expansion technique and effective truncation. Results clarified the influence on the dynamic stress concentration factor and magnetic field intensity concentration factor under proper conditions. Besides, the analytical solutions are compared with the finite element solutions to verify the accuracy of the conclusions in this article.

Genetic diversity of durum wheat (Triticum turgidum ssp. durum) to mitigate abiotic stress: Drought, heat, and their combination.

Drought and heat are the main abiotic constraints affecting durum wheat production. This study aimed to screen for tolerance to drought, heat, and combined stresses in durum wheat, at the juvenile stage under controlled conditions. Five durum wheat genotypes, including four landraces and one improved genotype, were used to test their tolerance to abiotic stress. After 15 days of growing, treatments were applied as three drought levels (100, 50, and 25% field capacity (FC)), three heat stress levels (24, 30, and 35°C), and three combined treatments (100% FC at 24°C, 50% FC at 30°C and 25% FC at 35°C). The screening was performed using a set of morpho-physiological, and biochemical traits. The results showed that the tested stresses significantly affect all measured parameters. The dry matter content (DM) decreased by 37.1% under heat stress (35°C), by 37.3% under severe drought stress (25% FC), and by 53.2% under severe combined stress (25% FC at 35°C). Correlation analyses of drought and heat stress confirmed that aerial part length, dry matter content, hydrogen peroxide content, catalase, and Glutathione peroxidase activities could be efficient screening criteria for both stresses. The principal component analysis (PCA) showed that only the landrace Aouija tolerated the three studied stresses, while Biskri and Hedhba genotypes were tolerant to drought and heat stresses and showed the same sensitivity under combined stress. Nevertheless, improved genotype Karim and the landrace Hmira were the most affected genotypes by drought, against a minimum growth for the Hmira genotype under heat stress. The results showed that combined drought and heat stresses had a more pronounced impact than simple effects. In addition, the tolerance of durum wheat to drought and heat stresses involves several adjustments of morpho-physiological and biochemical responses, which are proportional to the stress intensity.