Stress Concentration Area Research Articles

Acoustic Emission-Based Structural Health Prediction and Monitoring: A Comprehensive Review

In this paper, we report a detailed overview of non-destructive techniques, specifically Acoustic emission, for structural health monitoring in engineering applications. The review comprehensively covers the application of the AE technique for data related to damping and attenuation of structural components made from various material types, including conventional and non-conventional materials. Also, this paper systematically emphasizes research related to data collection processes of variable structural elements, such as stress concentration areas, sensor placement, and methodological monitoring. In addition, the analysis discussed in the review encompasses research that has utilized the AE method to examine the performance of metal and concrete building elements in risky situations, such as high temperatures and creep factors, with and without any visible signs of damage. We also examine various solution techniques, such as empirical wavelet transforms, finite element solutions, and differential quadrature for conventional materials’ damage analysis. Furthermore, the review emphasizes using waveform schemes to assess the vulnerability of damages in unconventional materials, such as laminated composite structures with different geometrical shapes. The paper concludes by presenting an overview of the current state of the AE technique in structural health monitoring and discusses potential future developments. This review is a valuable reference for professionals and researchers engaged in engineering applications related to structural health monitoring.

Review on stress evolution and crack propagation mechanism of double-crack specimens

The distribution pattern of cracks in rock masses, known as the geometric distribution, holds significant significance in understanding the progressive failure mechanism and stress concentration can lead to instability and even failure of the specimens. However, the macroscopic and microscopic mechanisms of crack coalescence and the failure of the sample are not yet clear. Thus, the discrete element method was used to investigate the influence of stress distribution on the fracture coalescence and failure of dual-crack specimens with different arrangements under uni-axial compression in this study. The obtained results were compared and analyzed with laboratory test results. The results show: When the double-crack specimens are under overlapping arrangement, the stress concentration area only appears at the end of the crack, which is conducive to crack propagation, resulting in no coalescence. However, if the two preexisting cracks were arranged in a co-planar or non-overlapping manner, the stress concentration of the sample would not only occur at the end of the cracks, but also between the cracks. As the stress increases, the cracks will gradually expand and connect, forming shear coalescence and mixed mode coalescence (shear and tensile) respectively. In addition, the arrangement of cracks greatly changes the influence of stress concentration on the failure mode of the specimen, leading to the possibility that the coalescence of the specimen may occur in three periods: before, during, and after the peak stress. The findings of this research hold immense importance in comprehending the mechanisms behind the coalescence and failure of rock fractures. Moreover, they provide valuable insights for the analysis and design of rock engineering projects, offering practical guidance for ensuring stability.

Notch Fatigue Life Research Based on Critical Distance Theory

Orthotropic anisotropic steel bridge panels are widely used in civil engineering due to their advantages of light deadweight, high ultimate bearing capacity, and wide range of applications. However, their fatigue problem is serious, and the fatigue-resistant design of the steel box girder diaphragm curved cutout is still difficult. In order to effectively predict the fatigue life of this typical fatigue-susceptible detail, a fatigue test of the specimen with curved notched segments of the diaphragm was carried out. ABAQUS 2016 version finite element analysis software was used to establish three kinds of finite element simplified models of the fatigue specimens with curved notches, and the laws of the influence of different notch radii on the fatigue life of the specimens were studied. Through the finite element solution of the three arc notch specimen models with different radii under the tensile load of 50 kN their respective principal stress distributions were obtained. The critical distance theory was introduced to analyze the characteristic stresses in the stress concentration area of the arc notch, and the point method and line method were used to calculate the characteristic stresses. The fatigue life prediction models of three kinds of notched components were established by combining the material fatigue limit and FE-safe life results. The results show that the point method is more conservative than the line method; no matter if the point method or the line method is used, the characteristic stress and the notch radius are inversely proportional to each other, and it is beneficial for the fatigue life of the structure to appropriately increase the notch radius. The fatigue prediction model of steel box girder diaphragms with curved notches based on the critical distance theory is of high accuracy, which is basically consistent with the test results, verifying the feasibility of the critical distance theory in the fatigue life prediction of notched specimens, and providing a reference for the fatigue life assessment of similar steel structures.

Investigation of Structural Strength and Fatigue Life of Rotor System of a Vertical Axial-Flow Pump under Full Operating Conditions

Axial-flow pumps consider both the conventional pump mode and the pump as turbine (PAT) mode operation and put forward higher requirements for long-term operation stability and structural strength; therefore, it is of great engineering significance to evaluate the structural strength and fatigue life of the rotor under full operating conditions. In this study, based on computational fluid dynamics and the one-way fluid-structure interaction algorithm, the structural strength and fatigue life of the rotor system of a large vertical axial-flow pump under full operating conditions were evaluated and studied. The results show that blade deformation and equivalent stress are generally higher in the PAT mode than in the pump mode. The maximum deformation in both modes occurs at the tip of the blade, while the area of stress concentration is at the root of the blade. Both the deformation and the equivalent stress increase with increasing flow rate. The minimum safety factor occurs at the blade root in both modes, and the safety factor in the PAT mode is relatively smaller than that in pump mode. Therefore, when designing and manufacturing axial flow pumps for turbine duties, priority should be given to material strength at the blade root during PAT mode operation to ensure safe and stable operation. The aim of this study is to provide technical references and theoretical foundations for evaluating the service cycle of axial-flow pumps and the influence on pump life under different operation modes.

Numerical analysis for tunnelling-induced stress and plastic evolution causing instability of multilayered surrounding rock by varying three-dimensional in situ stresses

PurposeThe induction of geological disasters is predominantly influenced by the dynamic evolution of the stress and plastic zones of the multilayer rock formations surrounding deep-rock roadways, and the behaviours and mechanisms of high in situ stress are key scientific issues related to deep-resource exploitation. The stress environment of deep resources is more complex owing to the influence of several geological factors, such as tectonic movements and landforms. Therefore, in practical engineering, the in situ stress field is in a complex anisotropic three-dimensional state, which may change the deformation and failure law of the surrounding rock. The purpose of this study is to investigate the tunnelling-induced stress and plastic evolution causing instability of multilayered surrounding rock by varying three-dimensional in situ stresses.Design/methodology/approachBased on data from the Yangquan Coal Mine, China, a finite difference model was established, and the elastic-plastic constitutive model and element deletion technology designed in the study were analysed. Gradual tunnelling along the roof and floor of the coal seam was used in the model, which predicted the impact tendency, and compared the results with the impact tendency report to verify the validity of the model. The evolutions of the stress field and plastic zone of the coal roadway in different stress fields were studied by modifying the maximum horizontal in situ stress, minimum horizontal in situ stress and lateral pressure coefficient.FindingsThe results shown that the in situ stress influenced the stress distribution and plastic zone of the surrounding rock. With an increase in the minimum horizontal in situ stress, the vertical in situ stress release area of the roof surrounding rock slowly decreased; the area of vertical in situ stress concentration area of the deep surrounding rock on roadway sides decreased, increased and decreased by turn; the area of roof now-shear failure area first increased and then decreased. With an increase in the lateral pressure coefficient, the area of the horizontal in situ stress release area of the surrounding rock increased; the area of vertical in situ stress release area of the roof and floor surrounding rock first decreased and then increased; the area of deep stress concentration area of roadway sides decreased; and the plastic area of the surrounding rock and the area of now-shear failure first decreased and then increased.Originality/valueThe results obtained in this study are based on actual cases and reveal the evolution law of the disturbing stress and plastic zone of multilayer surrounding rock caused by three-dimensional in situ stress during the excavation of deep rock roadways, which can provide a practical reference for the extraction of deep resources.

Analysis of the tribological behavior of the high-speed and heavy-load braking interface with dynamic wear of brake pads

Using a megawatt wind turbine disc brake as a case study, this work analyzes the effects and action mechanism of dynamic wear on the braking interface of the braking pad on tribological behaviors as contact state, temperature field, and pressure distribution. The Archard wear model was incorporated into the solution of the tribological problem of the braking interface in ABAQUS using the arbitrary Lagrangian–Eulerian (ALE) technique through the UMESHMOTION subroutine. The wear interface meshes were changed without modifying other finite element analysis variables. Moreover, wear testing on the inertia braking tester validated the coupled heat-stress-wear model of the brake pad. The differences in the tribological behaviors of the braking interface with and without the dynamic wear of the braking pad were analyzed based on the simulation results of friction and wear in a braking cycle. The study revealed that the tribological behaviors of the braking interface were significantly affected by the dynamic wear of the braking pad. Specifically, the wear evolution changed the contact state, the area of stress concentration, and the temperature field distribution during the braking process. Hence, the wear properties of the brake pad were modified as a result of these tribological behaviors.

Research on Optimization and Numerical Simulation of Layout Scheme of Mining Approach in Downward Slicing and Filling Method

The stability of the filling roof—as an important bearing unit in the stope of the access stope in the filling mining method—is of great significance to guarantee the safe and efficient production of the mine. Arrangement of the mining approach in downward cemented filling stope is the key factor affecting the stability of the filling body roof. Based on a combination of laboratory tests, theoretical analysis, and numerical simulation, the influence of different mining approach arrangements on the stability of the filling body roof is analyzed. The weak filling surface is formed between adjacent mining paths. The mechanical strength of the weak filling surface is significantly reduced by laboratory experiments. The relationship between the distribution of the weak filling surface, azimuth angle, and the stability of the filling roof is further studied by numerical simulation. The results show that, when the upper and lower layered mining approaches are arranged vertically or nearly vertically, the areas of stress concentration and the plastic zone in the numerical simulation results are the smallest, and the stability of the filler roof is the best.

Numerical simulation study on the evolution characteristics of the stress induced by mining in deep adjacent working faces

BackgroundThe mining-induced stress in the surrounding rock after coal seam mining is the primary cause of damage and failure of the surrounding rock in the mining area. However, the magnitude and direction of the stress field induced by mining in the overburden strata during the excavation process of deep and adjacent coal seams are not yet clear, and it is difficult to determine how adjacent working faces interact with each other.ResultsIn this study, a large-scale numerical model was built using FLAC3D (Fast Lagrange Analysis Continua) to simulate the sequential mining process of three adjacent working faces (No.1, No.2, and No.3) in Liuzhuang Coal Mine located in southern China. The results showed that the maximum height of plastic zone development after mining in the No.1 working face was 41 m, and the maximum height of plastic zone development was 33.8 m away from the 13 coal seam. It did not affect the top and bottom of the No.3 working face. The development height of the plastic zone on the roof of the No.2 working face after mining was 52m, and the top and bottom plates of the No.3 working face remained intact. The plastic zone of the floor of the No.3 working face after mining was not communicated with the plastic zone of the roof of the No.1 and No.2 working faces. There was a complete rock layer between the two coal seams, and there was not the mutual influence of the mining activities. During the mining process of working faces No.1 and No.2, the range of dynamic pressure influence was extended up to 100m ahead of the working face. During the mining process of the No.3 working face, the range of dynamic pressure influence was 120 m ahead of the working face. The No.1 working face goaf and the mining of No.2 working face had not disturbance to the No.3 working face.ConclusionsAfter the mining of No.1 and No.2 working faces, the stress in the goaf significantly decreased, and the lateral support stress concentration area of No.1 and No.2 working faces had a relatively small impact on the 13 coal seam. Therefore, the No.1 goaf and mining of No.2 working faces had not disturbance to No.3 working face.

Stress and strain changes of the anterior cruciate ligament at different knee flexion angles: A three-dimensional finite element study

ObjectiveThis study aimed to analyze the stress and strain changes of the anterior cruciate ligament (ACL) at different knee flexion angles using a three-dimensional finite element model. MethodsComputed tomography and magnetic resonance imaging scans were performed on the right knee of 30 healthy adult volunteers. The imaging data were used to construct a three-dimensional finite element model of the knee joint. The magnitude and concentration area of stress and strain of ACL at knee flexion angles 0°, 30°, 60° and 90° were assessed. ResultsThe magnitude of stress remained consistent at 0–30° (P > 0.999) and decreased at 30–90° (P < 0.001, P = 0.005, respectively), while the magnitude of strain increased between 0° and 30° (P = 0.004) and decreased between 30° and 90° (P < 0.001, P = 0.004, respectively). The stress concentration area remained consistent at the proximal end, midsubstance, and distal end between 0° and 60° (P > 0.05). The concentration area of strain increased at the proximal end, decreased at the midsubstance between 0° and 30°, and remained consistent between 30° and 90° (P < 0.001). ConclusionAt the low knee flexion angle, ACL's magnitude of stress and strain reached the peak, and the concentration area of ACL strain gradually shifted from midsubstance to the proximal end.

Quantitative evaluation of crack based on the sparse decomposition of array Lamb wave propagation

Crack damage is one of the significant factors that may accumulate at the stress concentration area of engineering structures and cause catastrophic accidents. In this paper, we proposed a novel approach to identify the crack location and size by exploiting the reflections and diffractions of Lamb waves. The interaction mechanism between the crack and Lamb wave has been analyzed thoroughly, our analysis of the interaction between the crack and Lamb wave revealed that both reflections and diffractions carry valuable damage information that reflects the size and orientation of the crack. As the interaction coefficients between these two components and the crack are different, there are supposed to exist differences between them in the amplitude value. We implemented a threshold to classify the signals received from all paths into two groups: reflections and diffractions. Then we constructed an overcomplete dictionary of waveforms corresponding to different propagation distances to extract the damage information. Using sparse decomposition, the received signals were mapped to their corresponding propagation distances without the use of baseline signals. The diffractions allow us to determine the crack's tip points, while the reflections provide information about the edge points. The kinked crack's size and orientation were visualized based on the time-domain signals acquired in our experiment. We provided a comprehensive description of our algorithm and verified it through numerical simulation and experimental data. Our results show high agreement with actual cracks, demonstrating the efficacy of our proposed method.

АНАЛИЗ МЕТОДОВ ОЦЕНКИ ПРОЧНОСТИ КОНСТРУКЦИЙ В ЗОНАХ КОНЦЕНТРАЦИЙ МЕХАНИЧЕСКИХ НАПРЯЖЕНИЙ

The analysis of methods for assessing strength in areas of mechanical stress concentrations in structures with defects is considered. As examples, the connections of a pipe with a welded shell and a technological pipeline with a through crack in the metal stratification zone delamination are given. It is shown that the calculation of structures with defects is based on the determination of the type of stress state that occurs under load, which is usually characterized by the value of the stiffness coefficient. Analysis of the study of a fragment of a technological pipeline in the zone of wall de-struction showed that the rupture occurred in the zone of the greatest wall thinning caused by the de-lamination of the wall metal, and the cause of the destruction was an excess of internal pressure

Stability analysis and deformation control method of swelling soft rock roadway adjacent to chambers

The surrounding rock of swelling soft rock roadway has high clay mineral content, strong expansibility after encountering water, low strength and poor cementation. The roadway is prone to large deformation under the influence of complex geostress. Combined with the support change of the development roadway of 2# coal in Hongqingliang mine, through geological survey, field observation and indoor test, the failure mechanism of the traditional support method of “anchor bolt + anchor cable + anchor mesh + shotcrete” was revealed by the adjustment of the surrounding rock stress after the excavation and support of the adjacent chambers. The research results show that the surrounding rock stress will cross the adjacent chambers and form a concentrated area near the weakly cemented roadway, and the maximum stress increase ratio of surrounding rock within the stress concentration range will reach 50%. The farther the chambers are from the weakly cemented roadway, the smaller the range of the surrounding rock stress concentration area. When the distance exceeds about 12 times the average height of the chambers, the surrounding rock stress concentration tends to disappear. Based on the fully enclosed combined support method of the "U-shaped steel sheds closure roof and sides + filling flexible material behind the sheds + laying reinforcement mesh and concrete in floor + strengthening key parts", the construction process flow applicable to the working condition of swelling soft rock roadway is formulated.

Experimental Study on Fatigue Damage of Drilling Tool Materials Based on Magnetic Memory Detection

In drilling engineering, the cost of drilling tool fracture is enormous, and studying the fatigue failure process of drilling tools has practical significance. This paper uses metal magnetic memory detection technology to design and conduct fatigue damage tests on typical drilling tool material 42CrMo specimens under tensile, torsional, compressive, tensile, compressive, and torsional dynamic loading conditions. By analyzing the changes in the tangential component Hp(x) and gradient value K of the magnetic memory signal under different load conditions with the number of loading times, the process of fatigue failure of the specimens and the trend of changes in the magnetic memory signal in local stress concentration areas are explored. The characteristic parameters of fatigue damage based on magnetic memory detection were extracted and the critical point at which fatigue damage leads to crack initiation was inferred. This confirms that metal magnetic memory testing technology is an effective means of analyzing the fatigue damage process of drilling tools and provides a certain reference for formulating judgment standards for drilling tool maintenance on site.

A Three-Dimensional Finite Element Analysis of the Stress Distribution Around the Bone Mini-Implant Interface Based on the Mini-Implant Angle of Insertion, Diameter, and Length.

Temporary anchorage devices or mini implants have gained great attraction due to their capability to provide absolute anchorage, low cost, versatility, and can be loaded immediately after placement. Finite element analysis was used to evaluate the distribution of stress at the bone mini implant interface based on different angles of insertion (30°, 45°, 60°, and 90°) mini implant diameter (1.3 mm, 1.6 mm, and 2 mm) and mini implant length (6 mm, 8 mm, and 10 mm). A retraction force of 2 N was applied. Areas of maximum stress concentration were the head and neck of the mini implant and cortical bone around the mini implant. A very minimal amount of stress was found in the cancellous bone. The maximum stress found in the cortical bone was 5.1301 MPa and in the mini implant was 26.355 MPa with an angle of insertion of 30°, a 1.3 mm diameter, and a 6 mm length. The minimum stress found in the cortical bone was 1.4702 MPa and that in the mini implant was 5.3895 MPa with an angle of insertion of 90°, a 2 mm diameter, and a 10 mm length. For maximum stability, mini implants should be placed at a perpendicular angle of insertion with sufficient diameter and length.

Simulation-based Fatigue Life Analysis of Polyimide Film in Afterburner Fuel Distributor

Aiming at the problem of premature failure of organic material polyimide film in the afterburner fuel distributor of a turbofan engine, the material parameters of polyimide film and the temperature and the fluctuation amplitude of the film during use were obtained based on previous investigation. The finite element simulation model of polyimide film was established in ANSYS software to study the Mises stress distribution and weak area distribution of the film when the film fails in the form of fracture. Based on the fatigue life calculation theory of probabilistic fracture mechanics, the fatigue life cycle times and their variation rules of the film under different reliability were obtained. The results show that there is stress concentration in the film, and the stress con-centration and weak area of the film occur at the outer edge of the film clamping. The fatigue life cycle times of the film under different reliability are calculated, and the fatigue life cycle times decrease with the increase of reliability.

Failure Analysis of a Diesel Engine Crankshaft based on Finite Element Modeling

The crankshaft is one of the essential components of an internal combustion engine that converts the piston's linear motion into the crank's rotary motion. This research has been carried out to study the failure analysis of diesel engine crankshafts, and forged steel material is selected. A crankshaft's geometry is relatively complex compared to other parts; its working conditions are critical, and the stress concentration areas are very complicated. While considering all these phenomena, it is significant that a crankshaft's fatigue strength, stiffness, durability, and wear resistance should be checked and analyzed properly. Firstly, a 3D model of the crankshaft is designed using SolidWorks 2022 software. After that, the Model is imported to ANSYS software 2022 R2 student version. However, using ANSYS (finite element method) is carried out on the crankshaft’s Model. This research aims to obtain the variation in stress magnitude at critical locations of the crankshaft by applying variable loads and boundary conditions. Simulation techniques were conducted for both static and dynamic analysis. The total deformation observed at the critical area of the crank pin is 1.3488e-8. The corresponding equivalent stress is 318.37, and the crankshaft's safety factor is 15.

Low-cycle fatigue behavior of a solution-treated and HIPped nickel-based single-crystal superalloy at 760 °C

Micropores have a substantial impact on the fatigue behaviors of nickel-based single-crystal (SX) superalloys. Nonetheless, Hot Isostatic Pressing (HIP) treatment is an available approach to effectively reduce defects and enhance fatigue lives. In this work, the HIP treatment was applied to a solution-treated second-generation nickel-based SX superalloy and then subjected to low-cycle fatigue (LCF) tests at 760 °C. The effects of HIP treatment on fatigue crack initiation and propagation at intermediate-temperature LCF were studied by analyzing the development of micropores and fatigue behaviors. The results show that HIP treatment can remarkably reduce the micropores and residual eutectics in the interdendritic regions of the solution-treated alloy, changing the crack initiation site from the sub-surface micropore to the surface microcrack and transforming the crack propagation from mode I (i.e., perpendicular to the load direction) to mode II (i.e., parallel to the crystallographic {111} planes). Consequently, HIP treatment can increase the fatigue lives of this SX superalloy by about three times. Due to the reduction of micropores and residual eutectics by HIP treatment, on the one hand, the surface microcrack can propagate through the oxide layer and recrystallization zone to form the crack initiation, effectively prolonging the time of the crack initiation stage. On the other hand, the elimination of stress concentration areas inhibits rapid crack propagation in the direction perpendicular to the stress axis, extending the life of the crack propagation. This research provides a method for controlling micropores and residual eutectics to improve the intermediate-temperature fatigue properties of the second-generation nickel-based SX superalloys.

Effect of a gap on the open hole tension strength of carbon fiber reinforced plastic laminates

Tensile tests of quasi-isotropic laminates with a circular open hole, which include a gap in the hole area, were conducted to demonstrate the effect of the gap on the strength. The test showed that the reduction in the open-hole strength owing to the gap was less significant than that in the no-hole tensile strength. A two-dimensional mechanical model of quasi-isotropic laminates with an arbitrary inclined gap was proposed and analytically solved to obtain a closed-form expression for the stress concentration. An approximate expression was provided as the sum of the global uniform stress field and the local stress field near the open hole, which was solved based on a complex variable method. The present analytical solution agrees well with the corresponding two-dimensional finite element solutions. The solution indicated that the stress increase owing to the gap is limited at the stress concentration area. The analytical results were consistent with the experimental results.

EFFECT AND LIMITATION OF PERIACETABULAR OSTEOTOMY FOR ACETABULAR DYSPLASIA CLARIFIED BY 3D FINITE ELEMENT ANALYSIS

Finite element analysis (FEA) has been applied for the biomechanical analysis of acetabular dysplasia, but not for biomechanical studies of periacetabular osteotomy (PAO) or those performing analysis taking into consideration the severity of acetabular dysplasia. This study aimed to perform biomechanical evaluation of changes in stress distribution following PAO and to determine the effect of the severity of developmental dysplasia of the hip (DDH) using three-dimensional FEA.A normal model was designed with a 25° center-edge (CE) angle and a 25° vertical-center-anterior margin (VCA) angle. DDH models were designed with CE and VCA angles each of 10, 0, or −10°. Post-PAO models were created by separating each DDH model and rotating the acetabular bone fragment in the anterolateral direction so that the femoral head was covered by the acetabular bone fragment, with CE and VCA angles each at 25°.Compared to the normal hip joint model, the DDH models showed stress concentration in the acetabular edge and contacting femoral head, and higher stress values; stress increased with decreasing CE and VCA angles. Compared to the DDH models, the post-PAO models showed near-normal patterns of stress distribution in the acetabulum and femoral head, with stress concentration areas shifted from the lateral to medial sides. Stress dispersion was especially apparent in the severe acetabular dysplasia models. PAO provided greater decreases in the maximum values of von Mises stress in the load-bearing area of the acetabulum and femoral head when applied to the DDH models of higher degrees of severity, although the values increased with increasing severity of DDH. PAO is expected to provide biomechanical improvement of the hip joint, although the results also suggest a limitation in the applicability of PAO for the patients with severe acetabular dysplasia.

Stresses in Teeth with External Cervical Resorption Defects Restored with Different Biomimetic Cements: A Finite Element Analysis

IntroductionThis study compared the stress distributions in teeth with simulated external cervical resorption defects restored with different restorative materials and identified areas of high stress concentration. MethodsA maxillary central incisor created in a scanned model using HyperWorks software (Altair Engineering Inc, Troy, MI) served as the control. External cervical resorption defects based on Shanon Patel’s classification were created (1Bd/2Bd/3Bd) in the scanned model. The defects were restored using mineral trioxide aggregate, Biodentine, glass ionomer cement, and Bioaggregate. On all the models, a force of 100 N was applied on the palatal aspect 2 mm incisal to the cingulum directed at 45° along the long axis of the tooth. ResultsThe stresses generated in dentin and cementum are less, with a restorative material having a high Young’s modulus. For the 1Bd defect, MTA and Bioaggregate showed least stresses in dentin and cementum, respectively, whereas Biodentine had consistently lower stresses in dentin and cementum. Larger defects like 2Bd and 3Bd restored with Bioaggregate exhibited minimum stresses in dentin and cementum. ConclusionsBioaggregate and Biodentine replace dentin with maximum stress and maximum strain. Elastic moduli similar to or higher than dentin are preferred for restoring cervical third resorptive lesions of the tooth.