Dissipation Characteristics Research Articles

Vibrational and Dissipative Characteristic Measurement of Solid-state Wave Gyroscope Resonators: Algorithms Based on the Identification of Free Oscillation Equations

The article describes the methodological basis for constructing computational circuits of different complexity degrees and different purposes for solving a wide range of industrial and laboratory problems to measure angular irregularity of vibrational-dissipative resonatorcharacteristics of integrating solid-state wave gyroscopes. The main method to solve such problems is the identification of the coefficients of the differential equations of quartz hemispherical resonator state in the mode of its free oscillations. The resonator oscillation equations both in the fixed measuring axes and in the moving axes of standing waves were chosen as the equations of state. After reduction to slow variables, only slowly changing amplitudeequations are left for identification problems. In all the described circuits, it is assumed that the information signals for the solved identification tasks are formed in a measuring device similar to the standard gyroscope device. These algorithms make it possible to measure the vibrational and dissipative characteristics of resonators with different degrees of completeness and directionality for different standard initial requirements to themeasurement accuracy and experimental modes, which makes it possible to reduce the measurement time and labor intensity of the established set of production control operations. Among the tasks to be solved for the free run-down mode of the resonator wave pattern are the following: angular irregularity measurement of the gyroscope resonator dissipative properties under conditions of low and significant residual frequency difference; angular non-uniformity measurement of gyroscope resonator vibrational properties (its different frequency); simultaneous measurement of resonator oscillatory and dissipative characteristics for fixed and special rotating gyroscope modes. The detailed processing of the computational schemes for the implementation of these algorithms is focused on their practical application for various tasks of production operational control. At the same time, the choice of the most suitable computational algorithm from the considered options depends on the conditions, requirements and specifics of measurements.

Research on Thermal Dissipation Characteristics Based on the Physical Laws of Forced Vibration in Granular Assemblies

Research on Thermal Dissipation Characteristics Based on the Physical Laws of Forced Vibration in Granular Assemblies

Analysis of braking performance and heat dissipation characteristics of multi-disc magnetorheological brake with an inner water-cooling mechanism

In order to improve the braking performance and reduce temperature rising of the magnetorheological (MR) brake during working condition, a multi-disc MR brake with an inner water-cooling mechanism is developed in this paper. The effective damping gaps are increased to eight sections by the four brake discs, which enhance the braking performance. An inner water-cooling mechanism is designed in the MR brake to improve the heat dissipation. The structure and working principle of the multi-disc MR brake are introduced, and the mathematical model of the braking torque and transient temperature field are established. The electromagnetic field simulation and the heat-flow coupling simulation are conducted by COMSOL software. A test rig is setup to investigate the braking performance and heat dissipation characteristics. The experimental results indicate the maximum braking torque can reach 96.24 N·m. Additionally, after 20 s of continuous braking, the temperature rise of the MR brake with cooling water input is lower than that without cooling water input. Compared with the braking torque reduction without cooling water input, the braking torque reduction with cooling water input is smaller. It is shown that cooling structures in the MR brake have a positive impact on improving braking performance.

A review of the effect of temperature on the performance of viscoelastic dampers

Abstract This paper introduces structure and characteristics of viscoelastic damper and analyses the effect of temperature on its performance. Elastic damper is a kind of damping device which mainly relies on the hysteretic energy dissipation characteristic of viscoelastic material to realize the purpose of structural shock absorption. It is widely used in vibration control of mechanical equipment and building structures. However, in the application and research of viscoelastic dampers, it is found that temperature has a significant effect on their performance. This paper first introduces the basic concept of viscoelastic dampers, and points out that there are few papers discussing the effect of temperature on viscoelastic dampers in recent years. In the second part of this paper, the structural composition and characteristics of viscoelastic dampers and viscoelastic materials are introduced. After that, this paper introduces the influence of temperature on the performance of viscoelastic damper from various aspects, and then focuses on the analysis of the influence of temperature on the energy dissipation performance of the damper.

Optimization and working performance analysis of liquid cooling plates in refrigerant direct cooling power battery systems

Refrigerant direct cooling is currently being considered as an efficient thermal management technology in power battery systems. In this paper, four types of liquid cooling plates for power battery modules are designed and the computational model is constructed. With the model being validated, it is applied to analyze the effects of the cooling plate structure and cooling channel on the cooling and heat dissipation performances. The results reveal that for the conventional cooling method, i.e., when the cooling plate is placed on the bottom of the battery pack, a significant temperature gradient in the vertical direction is observed. On the contrary, adopting a serpentine cooling plate structure in the main wall or parallel cooling channels in the narrow side wall could significantly reduce the temperature difference of the battery pack, which can keep the temperature difference within 5 °C even under extreme conditions. Further, a detailed analysis of the heat dissipation performance based on the optimal cooling plate structure is performed to determine the safe operating range of the battery pack. It is shown that as the humidity is less than 0.73 and the evaporation temperature is below 15.43 °C, the battery pack can operate safely. However, beyond this condition range the heat dissipation characteristics of the battery pack cannot satisfy the operating requirements. This work sheds light upon the potential of refrigerant direct cooling strategy in power battery thermal management systems by properly arranging the cooling plate.

Modeling of informative features based on the amplitude-phase frequency response during bioimpedance studies at a biological facility

The purpose of research is to develop and test a technique for forming informative features using descriptors for neural networks designed to assess medical risks based on the analysis of transient processes in biomaterial in a living organism (in vivo).Methods. Studies suggest the use of test electrical effects on areas of the body with unusual conductivity to obtain the amplitude-phase-frequency characteristic of the impe-dance of the biomaterial on which the specified effect was performed. The coordinates of the Cole graph of this biomaterial were used as key para-meters. To form the Cole graph, the Carson transform was used, based on transient data obtained using a four-terminal, where the main element is the impedance of the studied biomaterial. The input signals for the four-terminal were a sequence of sinusoidal pulses.Results. Based on the E20-10 data collection system manufactured by L-Card CJSC, a software and hardware complex has been developed for digitizing transient processes in four-terminal circuits, the element of which is the impedance of biomaterial in anatomical areas with abnormal electrical conductivity. Software in the Delphi programming language was developed to generate test signals and record biomaterial responses to these exposures. A theoretical model was also proposed explaining the conversion of the samples of the transition characteristic of the four-terminal with the impedance of the biomaterial to the Cole graph of this biomaterial.Conclusion. The study confirms that the use of a linear biomaterial impedance model contributes to the formation of descriptors based on the amplitude-phase-frequency characteristic, taking into account its dissipative properties. Building a Cole graph taking into account these dissipative characteristics allows us to develop classifiers of medical risks of socially significant diseases.

Hyperbolic Shear Metasurfaces.

Polar dielectrics with low crystal symmetry and sharp phonon resonances can support hyperbolic shear polaritons, which are highly confined surface modes with frequency-dependent optical axes and asymmetric dissipation features. So far, these modes have been observed only in bulk natural materials at midinfrared frequencies, with properties limited by available crystal geometries and phonon resonance strength. Here, we introduce hyperbolic shear metasurfaces, which are ultrathin engineered surfaces supporting hyperbolic surface modes with symmetry-tailored axial dispersion and loss redistribution that can maximally enhance light-matter interactions. By engineering effective shear phenomena in these engineered surfaces, we demonstrate geometry-controlled, ultraconfined, low-loss hyperbolic surface waves with broadband Purcell enhancements applicable across a broad range of the electromagnetic spectrum.

Investigation of the effect of geometric configurations on natural convection heat transfer in external flow

AbstractThe complexities of natural convection heat transfer are investigated through experimentation, focusing on the influence of geometric configurations such as spheres, cylinders, and cubes in external flows. The study aims to understand how different geometries affect heat transfer coefficients, providing insights for architectural and engineering applications. Experimental results revealed significant variations in heat transfer efficiency among geometric models, with cubic configurations exhibiting the lowest heat transfer rates compared with spherical and cylindrical counterparts. This underscores the critical impact of geometric configuration on thermal performance and heat dissipation characteristics. The findings highlight the necessity of considering geometric factors in design processes to optimize thermal management strategies. The study contributes to a deeper understanding of convective heat transfer mechanisms, emphasizing the importance of precise geometric modeling in enhancing energy efficiency and sustainability in built environments

Multi-Objective Optimization towards Heat Dissipation Performance of the New Tesla Valve Channels with Partitions in a Liquid-Cooled Plate

The utilization of liquid-cooled plates has been increasingly prevalent within the thermal management of batteries for new energy vehicles. Using Tesla valves as internal flow channels of liquid-cooled plates can improve heat dissipation characteristics. However, conventional Tesla valve flow channels frequently experience challenges such as inconsistencies in heat dissipations and unacceptably high levels of pressure loss. In light of this, this paper proposes a new type of Tesla valve with partitions, which is used as internal channel for liquid-cooled plate. Its purpose is to solve the shortcomings of existing flow channels. Under the working conditions of Reynolds number equal to 1000, the neural network prediction-NSGA-II multi-objective optimization method is used to optimize the channel structural parameters. The objective is to identify the optimal structural configuration that exhibits the greatest Nusselt number while simultaneously exhibiting the lowest Fanning friction factor. The variables to consider are the half of partition thickness H, partition length L, and the fillet radius R. The study result revealed that the optimal parameter combination consisted of H = 0.25 mm, R = 1.253 mm, L = 0.768 mm, which demonstrated the best performance. The Fanning friction factor of the optimized flow channel is substantially reduced compared to the reference channel, reducing by approximately 16.4%. However, the Nusselt number is not noticeably increased, increasing by only 0.9%. This indicates that the optimized structure can notably reduce the fluid’s friction resistance and pressure loss and slightly enhance the heat dissipation characteristics.

Mechanical Properties and Energy Damage Evolution Mechanism of Basalt Fiber-Modified Tailing Sand Cementation and Filling Body Mechanics

In order to investigate the mechanical properties of basalt fiber-doped tailing sand cemented filler and the evolution of energy damage, a uniaxial compression test was carried out on the basalt fiber-doped tailing sand cemented filler specimens to analyze the energy dissipation characteristics, and the damage constitutive equations with different basalt fiber contents were established based on damage mechanics. The results show that with the increase of fiber doping and fiber length, the uniaxial compressive strength and ductility of the filling body show a trend of increasing and then decreasing; the optimal value of fiber doping is 0.6%, and the optimal value of fiber length is 9 mm; the total strain energy, elastic strain energy and dissipation energy of basalt fiber-modified tailing sand cemented filling body at peak stress show a trend of increasing and then decreasing, and the energy dissipation energy of the filling body shows a trend of increasing and then decreasing. The energy dissipation energy shows a trend of increasing and then decreasing, and the energy dissipation energy shows a trend of increasing and then decreasing. The total strain energy, elastic strain energy, and dissipation energy at the peak stress show a trend of decreasing after increasing with the fiber doping and fiber length, and the energy damage evolution process can be divided into four stages: no damage stage, stable damage development stage, accelerated damage growth stage, and damage destruction; in addition, the existing damage constitutive model of the fiber-filled body was optimized, and the damage correction factor was introduced to obtain the damage constitutive model of the filled body with different fiber contents, and finally, after the verification of experimental and theoretical models, it was found that the two stress–strain curves coincided well. Finally, after the test and theoretical model verification, it is found that the stress–strain curves of the two are in good agreement, which indicates that the established theoretical model has a certain reference value for engineering practice, and at the same time, it has certain limitations.

Acoustic black hole with functionally graded perforated rings

A new class of acoustic black hole (ABH) waveguides is presented, which relies in its operation on an array of optimally designed functionally graded perforated rings (FGPRs). In this manner, the developed ABH is provided with built-in energy dissipation characteristics generated by virtue of the flow through perforations, which enhances its acoustic absorption behavior and makes the speed of the propagating waves vanish faster when reaching the end of the waveguide. Furthermore, the particular design of the rings enables sandwiching of additional porous absorbing layers between the rings to further boost the absorption characteristics of the proposed ABH. Accordingly, the operating principle of the new class of ABH is radically different from that of the conventional ABH that employs sequential solid-flat rings of decreasing inner radii to create a virtual power law taper necessary for generating the black hole effect, but through reactive means rather than the effective dissipative means of the proposed ABH. Therefore, this paper develops a transfer matrix modeling (TMM) approach to model the absorption and reflection characteristics of the new class of ABH, in an attempt to predict its behavior, optimize the selection of its design parameters, and more importantly, demonstrate its merits as effective means for controlling sound propagation. Numerical examples are presented to highlight the merits and behavior of the proposed ABH. Predictions of the TMM are validated against experimental results that are available in the literature for one and two micro-perforated plates. Comparisons are also established between the ABH with FGPR and the conventional ABH in order to distinguish the behavior and underlying principles of their operations.

A size‐dependent energy‐based strain burst criterion

AbstractThis paper presents a size‐dependent energy‐based strain burst criterion linking strength, elasticity, fracture energies and specimen size effect with stress state due to changes in boundary conditions. It proposes the concept of a ‘Burst Envelope’, a surface in three‐dimensional principal stress space derived based on energy storing and dissipation characteristics of a rock sample, taking into account the size of the specimen and potential localised failure pattern. A scalar burst index is also proposed to quantify the bursting scale. To illustrate and verify its functioning, a numerical modelling framework based on the distinct element method and employing a new cohesive‐frictional contact model is used to perform virtual strain burst experiments under different polyaxial loading‐unloading scenarios, mimicking various underground excavation scenarios. The obtained results are in good agreement with the theoretical prediction of burst occurrence. On that basis, the variation of burst possibility and magnitude are investigated with key factors, including confinement level and the material's elastic, strength and fracture properties. The effect of the specimen's aspect ratio and size on the rock burst potential is elaborated and verified using virtual strain burst experiments, facilitating the linking of the proposed theoretical framework with the evaluation of in‐situ strain bursts in rock masses around underground openings.

METHOD OF ASSESSING THE CHANGE IN DESIGN PARAMETERS OF PRECISION ROTARY SYSTEMS BY THE PHASE SHIFT OF THE VIBRATION STATE

The article examines the issue of precision rotary systems (PRS) and the relationship between their dissipative characteristics and changes in design parameters, which is applicable for assessing the quality of their assembly and diagnosing objects in general. We identified a dynamic model, the dissipative parameters of which sufficiently accurately reflect the local properties of the structure. The question of assessing the quality of assembly by dissipative parameters comes down to the choice of the diagnostic sign that is most suitable for this case and the method of its measurement. Such a sign is a phase shift between the disturbance force and the vibration velocity. From this point of view, phase-frequency measurement methods are generally more accurate, which allows using the advantages of precise hardware methods to obtain information to the fullest extent. The proposed variation ratio, which connects the changes in a real object’s phase vector of the mechanical impedance (PVMI) and the deviation of the dissipative parameters of its mathematical model, makes it possible to diagnose the dissipative parameters with a sufficient accuracy degree. The considered numerical example of a partial assembly of precision rotary systems confirms the accuracy of the calculation. Thus, the proposed variation ratio, which connects the changes in the PVMI of a real object and the deviation of the dissipative parameters of its mathematical model, allows for the diagnosis of the dissipative parameters with a sufficient accuracy degree. The considered numerical example of a partial assembly of the PRS confirms the accuracy of the calculation. This fact is of particular importance in manufacturing aviation and space technology products. We should also note that the existing analysis methods do not provide an opportunity to form an idea about the nature of the total measured signal and its structure. Therefore, the work solves the task of developing a method for diagnosing the controlled technical condition of a rotary electromechanical system based on the selection of the most informative ranges of the output signal to increase the reliability of diagnosis. Keywords: oscillatory system, dissipative properties, mathematical model, phase angle, impedance, sensitivity matrix.

METHOD OF ASSESSING THE CHANGE IN DESIGN PARAMETERS OF PRECISION ROTARY SYSTEMS BY THE PHASE SHIFT OF THE VIBRATION STATE

The article examines the issue of precision rotary systems (PRS) and the relationship between their dissipative characteristics and changes in design parameters, which is applicable for assessing the quality of their assembly and diagnosing objects in general. We identified a dynamic model, the dissipative parameters of which sufficiently accurately reflect the local properties of the structure. The question of assessing the quality of assembly by dissipative parameters comes down to the choice of the diagnostic sign that is most suitable for this case and the method of its measurement. Such a sign is a phase shift between the disturbance force and the vibration velocity. From this point of view, phase-frequency measurement methods are generally more accurate, which allows using the advantages of precise hardware methods to obtain information to the fullest extent. The proposed variation ratio, which connects the changes in a real object’s phase vector of the mechanical impedance (PVMI) and the deviation of the dissipative parameters of its mathematical model, makes it possible to diagnose the dissipative parameters with a sufficient accuracy degree. The considered numerical example of a partial assembly of precision rotary systems confirms the accuracy of the calculation. Thus, the proposed variation ratio, which connects the changes in the PVMI of a real object and the deviation of the dissipative parameters of its mathematical model, allows for the diagnosis of the dissipative parameters with a sufficient accuracy degree. The considered numerical example of a partial assembly of the PRS confirms the accuracy of the calculation. This fact is of particular importance in manufacturing aviation and space technology products. We should also note that the existing analysis methods do not provide an opportunity to form an idea about the nature of the total measured signal and its structure. Therefore, the work solves the task of developing a method for diagnosing the controlled technical condition of a rotary electromechanical system based on the selection of the most informative ranges of the output signal to increase the reliability of diagnosis. Keywords: oscillatory system, dissipative properties, mathematical model, phase angle, impedance, sensitivity matrix.

Improving the cooling effect of proton exchange membrane fuel cells by using biomimetic capillary cooling channels based on topology optimization method

Proton exchange membrane hydrogen fuel cells (PEMFCs) are promising energy conversion devices, capable of directly converting chemical energy into electrical energy. However, the ideal operating temperature range for PEMFCs is narrow, and the intense exothermic reactions can easily lead to internal temperatures exceeding optimal levels. Thus, carefully designed cooling channels are crucial to maintain proper operating temperatures. Drawing inspiration from the heat dissipation characteristics of human capillaries on the skin, this study develops three biomimetic capillary cooling channels using a two-objective topology optimization approach. The heat transfer performance of these biomimetic cooling channels is compared against traditional parallel channels (TPC). Additionally, two new flow channel designs with varying inlet and outlet configurations are analyzed. The study examines the impact of different weight factors on the biomimetic cooling channels and uses Pareto frontiers to compare the results from varying weight factors. Findings indicate that topology-optimized biomimetic cooling channels can significantly enhance overall performance. Using a PEC = 1 for TPC as a benchmark, the biomimetic channels achieve average PECs of 1.72, 3.03, and 3.77, indicating superior performance over TPC. Furthermore, the ratio of weight factors also plays a role in the formation of cooling channels. The model with a weight factor ratio of w1:w2 = 0.6:0.4 for double inlets and double outlets arranged in opposite directions shows improved performance. Lastly, this study outlines a design guideline for PEMFC cooling channels based on biomimetic capillary structures and the appropriate ratio of the double objective functions to enhance heat dissipation performance.

Preparation and performance of steel slag and recycled brick aggregate modified concrete under the background of solid waste application

Permeable concrete has the characteristics of breathability, permeability, and high heat dissipation. To improve its mechanical and frost resistance properties, this study optimized the preparation and performance of permeable concrete by adding materials to improve its performance. The performance analysis validate that epoxy resin owns a filling effect on the pores of permeable concrete. The internal curing agent, high water absorbent resin, has a good water absorption effect. The synergistic effect of these two increases the density and compressive strength of permeable concrete. When the two contents are 0.5%, the maximum compressive strength of modified permeable concrete at 7 and 28 days was 15.62 and 17.97 MPa, respectively. Under the action of freeze-thaw cycles, its mass loss rate show an upward trend By comparison, epoxy resin and high water absorbent resin are beneficial for improving the frost resistance of permeable concrete. The minimum value of relative dynamic modulus of elasticity remains stable at over 80%, and the loss rate of dynamic modulus of elasticity is all below 0.4. However, the influence of epoxy resin and SAP on the mass loss rate is relatively small, and the mass loss of all experimental groups is controlled below 2.5%. The binomial Fourier function model is the best predictive model for permeable concrete under freeze-thaw cycles. This study has positive significance for improving the performance of permeable concrete and maintaining the sustainable development of ecological cities.

Influence of impeller energy dissipation characteristics of multi-blade axial flow pump impeller by the cascade density

Abstract This paper investigates the influence of cascade density on energy dissipation in the impeller of a multi-blade axial-flow pump. Three-dimensional transient numerical simulations were conducted using the SST k-ω turbulence model for impeller schemes with different cascade density, corresponding to different blade chord length and pitch. Entropy production theory was applied to locate the regions with high energy loss in the impeller. The relationships between local entropy generation, energy loss, and unsteady flow were analyzed for different cascade density. The results indicate that impeller entropy output of the multi-blade axial-flow pump is highly consistent with the head loss during testing. Turbulence dissipation accounts for more than 50% of the total energy loss, followed by wall friction, while direct dissipation is the smallest contributor. The relative loss of the impeller can be minimized by decreasing the number of blades or increasing the blade chord length. By comparing energy dissipation in blade rotation with different chord length and pitch, it is found that turbulent dissipation ability can be controlled more effectively by changing chord length, while the ability of direct dissipation can be controlled more effectively by changing the pitch.

Research on the theory and method of reduced-hole blasting for large cross-section tunnel based on explosive energy dissipation

The traditional tunnel drilling and blasting method places cut holes at the lower center of the excavation face, resulting in an excessive number of blasting holes. With the continuous increase in cross-section area, this design concept can no longer meet the requirements of safe and efficient tunnel boring for large cross-section tunnels. This paper puts forward the theory and method of reduced-hole blasting for large cross-section tunnels, as an alternative to the traditional drilling and blasting method of the “more holes, less charge” design concept. Based on the explosion energy dissipation law and rock’s critical crushing energy dissipation characteristics, the calculation method of the extrapolation distance of the wedge-cut holes is given. The optimum extrapolation distance of the wedge-cut holes was verified using numerical simulation and field tests. The results show that the number of drilling holes can be reduced by about 15.8% using the theory and method proposed in this paper, and at the same time, the damage of retained rock can be effectively controlled. The results of this study can provide a reference for the design of blast network parameters for similar large cross-section tunnels.

Macro‐meso damage cracking and energy dissipation of rock‐backfill composites: Effect of cyclic disturbance frequency

AbstractThis work aims to reveal the effect of cyclic disturbance frequency, i.e., 0.01, 0.1, 0.5, and 1.0 Hz, on damage cracking and energy dissipation characteristics of rock‐backfill composite structure specimens. Testing results show that fatigue volumetric strain and secant modulus increase with increasing disturbance frequency; low‐frequency disturbance leads to an earlier volume expansion. In addition, the strain energy density increases with increasing disturbance frequency. Most of the energy are dissipated for the specimen under high‐frequency disturbance. Finally, computed tomography scanning reveals the influence of disturbance frequency on failure modes; tensile‐splitting failure and shear failure are likely to occur at the surrounding rock subjected to high‐ and low‐ frequency disturbances. Low‐frequency‐disturbed stress seems easily to stimulate cracks at the rock‐backfill interfaces and the backfill; the backfill can absorb much more energy than high‐frequency circumstances. It is suggested that the role of backfill in energy absorption, contact support, and stress isolation is disturbance frequency dependent.

On elastoplastic behavior of porous enamel–An indentation and numerical study

The micro/nano pores in natural mineralized tissues can, to a certain extent, affect their responses to mechanical loading but are generally ignored in existing indentation analysis. In this study, we first examined the void volume fraction of sound and caries lesion enamels through micro-computed tomography (micro-CT). A Berkovich indentation study was then carried out to characterize the effect of porous microstructure on the mechanical behavior of the human enamels. The indentation tests were also modeled using the nonlinear finite element analysis technique to simulate indentation load-displacement curves, which showed reasonable agreement with the experimental measurements. From the simulation results, the extent of densification in the plastic zone was identified and the corresponding stress and contact pressure evolutions were quantified. Further, a conventional elastic-perfectly plastic material model without considering micropores was also developed to investigate the compaction effect of the porous structure. The simulation results reveal that conventional elastic perfect-plastic constitutive models become less reliable to model the mechanical behavior of carious lesion enamel with increasing loss of mineral content as it underestimates the yield stress and plastic energy dissipation. This study divulges the importance of compaction of porous enamel structure beneath the indented area. Note that understanding the effect of porous microstructures on plastic behavior is vital as the involved inelastic deformation mechanism associated with irreversible processes, such as wear and localized microcracking, has a significant bearing on wear and fatigue behavior of enamel. Statement of significanceBased on micro-CT and nano-indentation characterization, a numerical model was developed aiming to precisely describe the deformation behavior of naturally porous enamel. Inelastic properties and energy dissipation characteristics of porous enamel were investigated in detail. This work demonstrated that the existence of micro-pores in White Spot Lesions (WSLs) contributes to mechanical stability, which can mitigate the reduction in Young's modulus and fracture toughness resulting from loss of mineral components. The knowledge gained from this study can be used to explain the mechanisms related to irreversible processes, such as contact induced cracking and wear, and strengthen understanding of the mechanical behavior of porous mineralized tissues.