Showing papers on "Tensile testing published in 1993"
TL;DR: The fatigue life of microcellular polycarbonate specimens of five different relative densities ranging from 0.52 to 0.97 was measured in tension-tension tests on dumbbell specimens.
Abstract: The fatigue life of microcellular polycarbonate specimens of five different relative densities ranging from 0.52 to 0.97 was measured in tension-tension tests on dumbbell specimens. Fatigue life va...
171 citations
20 Dec 1993-Materials Science and Engineering A-structural Materials Properties Microstructure and Processing
TL;DR: In this article, the Weibull slopes of 11, 20 and 38 were obtained for the TF, TBF and TFBF castings respectively, respectively, with the best description of the skewed distributions of tensile strengths of each set of castings was obtained with the weibull distribution.
Abstract: Al7SiMg alloy vertically cast test bars were produced in dry sand moulds by top filling (TF), turbulent bottom filling (TBF) and turbulence-free bottom filling (TFBF) with filtered metal. The test bars were heat treated prior to tensile testing. Scanning electron microscopy examination of polished sections showed that all the test bars contained tangled networks of oxide films which are seen to constitute cracks within the metal. They are more prevalent in the TF and TBF castings. A large number of anomalous features are observed on all fracture surfaces. These are oxide films produced during filling and entrained in the casting. The best description of the skewed distributions of tensile strengths of each set of castings was obtained with the Weibull distribution. Weibull slopes of 11, 20 and 38 were obtained for the TF, TBF and TFBF castings respectively.
144 citations
TL;DR: In this paper, a mathematically well defined criterion is developed, based on the standard deviations of the values of the stresses in the test section, to evaluate the suitability of a specimen design, and the performance of the obtained optimized specimen design is investigated in the case of off-axes tests on anisotropic materials.
Abstract: F or experimental investigations concerning the mechanical behaviour under biaxial stress states of rolled sheet metals, mostly cruciform flat specimens are used. By means of empirical methods, different specimen geometries have been proposed in the literature. In order to evaluate the suitability of a specimen design, a mathematically well defined criterion is developed, based on the standard deviations of the values of the stresses in the test section. Applied to the finite element method, the criterion is employed to realize the shape optimization of biaxial cruciform specimens for isotropic elastic materials. Furthermore, the performance of the obtained optimized specimen design is investigated in the case of off-axes tests on anisotropic materials. Therefore, for the first time, an original testing device, consisting of hinged fixtures with knife edges at each arm of the specimen, is applied to the biaxial test. The obtained results indicate the decisive superiority of the optimized specimens for the proper performance on isotropic materials, as well as the paramount importance of the proposed off-axes testing technique for biaxial tests on anisotropic materials.
142 citations
TL;DR: In this article, the elastic stress fields in spheres under conditions of quasi-static compression and free impact against plane targets were derived for the brittle fracture of spheres under compression and impact loading and some anomalies observed in indirect methods of tensile testing were clarified.
Abstract: Numerical values are derived for the elastic stress fields in spheres under conditions of quasi-static compression and free impact against plane targets. The results are relevant to the brittle fracture of spheres under compression and impact loading and allow some anomalies observed in indirect methods of tensile testing to be clarified.
133 citations
TL;DR: In this article, the effect of randomly distributed fiber reinforcement on the response of cemented sand to load was evaluated in triaxial static compression, cyclic compression, and splitting tension tests.
Abstract: Triaxial static compression, cyclic compression, and splitting tension tests were performed to evaluate the effect of randomly distributed fiber reinforcement on the response of cemented sand to load. Test results indicated that fiber reinforcement significantly increases the compressive and splitting tensile strength of cemented sand. An increase in the compressive and tensile strength was found to be more pronounced at higher fiber contents and longer fiber lengths. Peak strength envelopes in compression indicated that both the friction angle and cohesion intercept of cemented sand were increased as a result of fiber inclusion. Inclusion of fibers also contributed to increased brittleness index of cemented sand while increasing its total energy absorption capacity. Fiber reinforcement also affected the response of cemented sand to cyclic load by significantly increasing the number of cycles, and the magnitude of cyclic strain needed to reach failure.
128 citations
TL;DR: In this article, a tensile testing method for thin films is presented, where the strain is measured directly on the unsupported thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography.
Abstract: A new method for tensile testing of thin films is presented. The strain is measured directly on the unsupported thin film from the displacement of laser spots diffracted from a thin grating applied to its surface by photolithography. The diffraction grating is two-dimensional, allowing strain measurement both along and transverse to the tensile direction. In principle, Young’s modulus, Poisson’s ratio, and the yield stress of a thin film can be determined. Cu, Ag, and Ni thin films with strong ⟨111⟩ texture were tested. The measured Young moduli agreed with those measured on bulk crystals, but the measured Poisson ratios were consistently low, most likely due to slight transverse folding of the film that developed during the test. The yield stresses of the evaporated Cu and Ag thin films agreed well with an extrapolation of the Hall-Petch relation found for bulk materials. Ni thin films are known to deviate from a bulk Ni Hall–Petch relation for submicron grain sizes, and sputtered Ni films show much higher yield stresses than electrodeposited or vapor-deposited films of similar grain size. Our sputtered Ni films had higher yield stresses than other sputtered films from the literature.
114 citations
TL;DR: In this paper, a simple geometrical model is proposed to predict the failure strain as a function of the reinforcement content, aspect ratio and strain to failure of the unreinforced matrix.
Abstract: The formation of cavities in commercially pure aluminium composites, made by both powder and casting routes and reinforced with alumina (short fibres, angular particles and spherical particles), has been monitored using periodic density measurements during tensile testing and microstructural examinations. Stable cavities always form well before final failure, usually adjacent to the reinforcement, particularly when it is elongated in the loading direction and has a relatively flat surface normal to the stress axis. Sharp corners are not favoured cavitation sites and cavities can form at spherical particles, although the incidence is somewhat less than for angular particles. Cavitation occurred earlier for higher reinforcement contents and with powder-route, as opposed to cast, material, although the void contents and composite strains at failure were similar. A simple geometrical model is proposed, allowing prediction of the failure strain as a function of the reinforcement content, aspect ratio and strain to failure of the unreinforced matrix. The data presented are in good agreement with predictions from this model.
113 citations
TL;DR: In this article, the effect of microstructural parameters on the fracture behavior of silicon carbide particle reinforced aluminium matrix composites has been carried out and a linear relationship between damage initiation rate and strain was found.
Abstract: A systematic study of the effect of microstructural parameters on the fracture behaviour of silicon carbide particle reinforced aluminium matrix composites has been carried out. Acoustic emissions have been monitored during tensile testing, giving the size and number of emmissions as a function of strain. This has been shown to be simply related to the rate of void nucleation at the reinforcing phase. Both particle fracture and particle/matrix decohesion mechanisms can be detected. Void nucleation was observed from the onset of plastic deformation and a linear relationship between damage initiation rate and strain was found. The rate of emission increased with reiforcing particle size and volume fraction but was independent of matrix alloy composition and heat treatment. These results show that the failure strain of particulate metal matrix composites is not controlled solely by the onset of void nucleation at the reinforcing phase. Local failure processes in the matrix are shown to promote void coalescence and dominate the ductility. However, suppression of void nucleation at the particles increases the ductility. It is suggested that a critical number of fractured particles is required before failure.
107 citations
TL;DR: In this paper, UHMPE and HDPE composites were fabricated under various processing conditions and the tensile strength and modulus values of composite appeared to be fairly high and close to those reported for other composites reinforced with polyethylene (PE) fibers.
Abstract: Drawing on the difference in melting points of UHMPE fiber (150°C) and HDPE matrix (130°C), single-polymer composites were fabricated under various processing conditions. Because of the chemical similarity of the composite components, good bonding at the fiber-matrix interface could be expected. The matrix, the fiber, and unidirectional composite laminae were studied using TMA and DSC analyses, a hot-stage crystallization unit attached to a polarizing microscope, and an universal tensile testing machine. The TMA showed negative thermal expansion of the fiber over the complete temperature range of the experiment. Three regimes of contraction according to the values of the thermal expansion coefficient were detected. DSC analyses of either the fiber or the composite specimens did not show any appreciable changes after various thermal treatments. They also showed no evidence of fiber relaxation during manufacture, probably because of the pressure-related transverse constraint. The tensile strength and modulus values of the composite appeared to be fairly high and close to those reported for other composites reinforced with polyethylene (PE) fibers. An apparent maximum on the temperature dependencies of tensile properties was observed. A study of the matrix microstructure did not give any proof of transcrystalline growth at the fiber-matrix interface even for chemical or plasma surface-treated fibers. © 1993 John Wiley & Sons, Inc.
101 citations
TL;DR: In this article, a parametric study was conducted to explore the theoretical basis for the difference in tensile and compressive shaft capacity of a pile under tensile loading and uplift.
Abstract: In most soil types, it is generally assumed that the shaft capacity of a pile is identical under both tensile and compressive loading. However, there is widespread experimental evidence that in sand the shaft capacity is significantly lower for tensile loading, or uplift, than for compressive loading. This paper describes the results of a parametric study that was conducted to explore the theoretical basis for such differences. It is shown that the primary cause of lower tensile capacity is due to a Poisson’s ratio effect, and that the ratio of tensile to compressive shaft capacity may be expressed as a function of the relative compressibility of the pile and the slenderness ratio. Design recommendations are proposed, and corroborated with results from high-quality field tests.
100 citations
TL;DR: The deformation behavior of a DO19 compound with an off-stoichiometric composition of Ti-36·5 at.% Al has been studied at room temperature both in tension and compression as discussed by the authors.
Abstract: The deformation behaviour of single crystals of a DO19 compound with an off-stoichiometric composition of Ti-36·5 at.% Al has been studied at room temperature both in tension and compression. A tensile elongation as large as 250% has been observed for an orientation where prism slip is fully operative, indicating that the compound is soft and quite deformable in single crystalline form for a certain orientation range. Tensile elongation is not sensitive to test environment and decreases with increasing strain rate. This indicates that the present compound is not susceptible to severe environmental embrittlement. For the basal slip orientations, however, failure occurs soon after yielding even in compression due to the formation of deep shear cracks along basal slip planes. Prism slip obeys the Schmid's law and the critical resolved shear stress is considerably smaller than those for basal and pyramidal slip (one-third and one-ninth, respectively). Based on the results obtained, factors causing th...
TL;DR: In this article, the tensile and fatigue behavior of unidirectional carbon-high-performance polyethylene/epoxy hybrid composites has been studied, including the effect of hybrid design and surface treatment of the high-performance PU fibres.
TL;DR: In this article, the surface structure of the Kevlar fibers, untreated or treated by oxygen plasma, catalyst grafted, or ethylene polymerized, was characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR), and scanning electron microscopy (SEM).
Abstract: In this article, plasma-treated KevlarTM fiber-polyethylene composites prepared by the catalytic grafting technique were studied. The reactive groups COOH, OH, NH2 generated on the Kevlar fiber surface by oxygen plasma treatment were used to chemically anchor Ziegler-Natta catalyst, which was then followed by ethylene polymerization on the fiber surface. The surface structure of the Kevlar fibers, untreated or treated by oxygen plasma, catalyst grafted, or ethylene polymerized, was characterized by X-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR), and scanning electron microscopy (SEM). The morphology, interfacial behavior, and mechanical properties of the high-density polyethylene (HDPE) composites reinforced by either catalytic grafted or ungrafted Kevlar fibers were investigated by means of differential scanning calorimetry (DSC), polarized light optical microscopy, tensile testing, and SEM. Special attention was devoted to the tensile properties of the composites in the direction transverse to the fibers. The experimental results show that oxygen plasma treatment increases the reactive site concentration on the fiber surface significantly and that the composites reinforced by catalytically grafted Kevlar fibers exhibit higher tensile strength both parallel and transverse to the fibers. The improved interfacial adhesion is attributed to the interfacial chemical bonding established by catalytic grafting. © 1993 John Wiley & Sons, Inc.
TL;DR: In this article, two types of brittle reticulated materials were evaluated under uniaxial tensile and compressive loading and analyzed in terms of the Gibson and Ashby model for brittle open-cell solids.
Abstract: Two types of brittle reticulated materials were evaluated under uniaxial tensile and compressive loading and analyzed in terms of the Gibson and Ashby model for brittle open-cell solids. The samples consisted of an open-cell alumina-mullite material which was tested as a function of density at a constant cell size and a reticulated vitreous carbon tested at one density and two cell sizes. The samples were mounted such that only the loading direction was varied in the tests. A combination of video photography and acoustic emission was critical to interpreting the results. The model assumes that identical deformation modes, bending failure of the struts, are responsible for failure of the bulk foam in tension and compression. The results of this work indicate a significant difference between the density dependence in tension and compression. Tensile failure in both materials appeared to be characterized by the catastrophic propagation of a single crack. Compressive failure was significantly different between the alumina and glassy carbon foams. The alumina foam failed by a damage accumulation process, whereas the carbon foam failed by the catastrophic collapse of a band of cells perpendicular to the loading direction.
TL;DR: In this article, the authors investigated the bakehardening behavior of a deep drawing steel sheet and found that the increase in the yield stress by simulated baking treatment occurs in two successive steps, the first rise is based on the Cottrell effect and the further strengthening in the second step is caused by the precipitation of coherent carbides.
Abstract: The bake-hardening behaviour of a deep drawing steel sheet was investigated. Aging experiments after different prestrains were carried out in the temperature range from 50 to 180 °C. The change of mechanical properties, especially the increase in yield stress, was measured by tensile tests. It was found that the increase in the yield stress by simulated baking treatment occurs in two successive steps. It is assumed that the first rise is based on the Cottrell-effect and the further strengthening in the second step is caused by the precipitation of coherent carbides. A kinetic interpolation-model of the bake-hardening effect is introduced and this allows a description of the experimental data and a calculation of the bake-hardening behaviour
TL;DR: In this paper, tensile testing of metastable austenitic stainless steel, either in air or vacuum after thermal charging with hydrogen or in hydrogen without prior charging, reveals a significant loss in ductility that is dependent upon strain rate only at low hydrogen levels or when testing in a hydrogen atmosphere.
TL;DR: More than 100 different formulations of calcium-orthophosphate cements were subjected to determinations of the compressive strength and the diametral tensile strength after storage at room temperature for 24 h under 100% relative humidity (RH) as mentioned in this paper.
Abstract: More than 100 different formulations of calcium-orthophosphate cements were subjected to determinations of the compressive strength and the diametral tensile strength after storage at room temperature for 24 h under 100% relative humidity (RH). It was found that setting occurred on more than 15 combinations of reactants. Further, it was shown that the mechanical properties of the cements which were obtained were also dependent on the water/powder ratio, the content of seed material and the storage conditions. Other factors which are thought to be of importance are the particle form and the particle size of the powder constituents as well as the addition of modifiers.
TL;DR: In this article, the authors determined whether recrystallization alone had an effect on the room temperature tensile properties of a Fe[sub 3]Al-based alloy, and found that the best tensile strength and ductility were attained in specimens which had been heat treated to relieve stresses produced by the fabrication process but that had a minimum number of recrystized grains.
Abstract: The purpose of the present study was to determine whether recrystallization alone had an effect on the room temperature tensile properties of a Fe[sub 3]Al-based alloy The best room temperature tensile strength and ductility were attained in specimens which had been heat treated to relieve stresses produced by the fabrication process but that had a minimum number of recrystallized grains The exact mechanism for this improvement is unclear, but could involve texturing effects or the enhancement of dislocation mobilities Also the elongated grain structure characteristic of as-rolled material provides a minimum of transverse cleavage planes (as well as a minimum of grain boundaries), and could simply be disrupting the path of atomic hydrogen entering the specimen during tensile stressing
TL;DR: In this paper, a simple model is proposed which allows prediction of the failure strain for a given reinforcement volume fraction and aspect ratio, based on the constraining effect of the reinforcement on plastic deformation in adjacent regions of matrix and the contribution of cavitation to the observed strain.
TL;DR: In this article, a review of the general area of tensile dilatometry for polymeric materials is presented, together with a brief literature review for volumetric response of a material to a deformation.
Abstract: The theory for volume changes in deformation for polymeric materials is presented, together with a brief literature review of the general area of tensile dilatometry. The theory has been used to enable the prediction of the volumetric response of a material to a deformation, which allows for the detection of the onset of cavitation (volume increasing)-type mechanisms in materials displaying such responses. A series of experiments has been performed using an instrumented tensile dilatometry technique on PMMA and on talc-filled reinforced polypropylene at 23 and 60 °C. The engineering constants, tensile modulus and lateral contraction ratio were measured and found to be viscoelastic. The determination of strain in three mutually perpendicular directions during the instrumented tensile test resulted in the measurement and prediction of the volumetric strain response with applied load. A significant cavitation-type mechanism was recorded in the case of the talc-filled reinforced polypropylene, whereas PMMA showed a deviatoric type mechanism. The volume strain has been found to be directly related to the bulk modulus for these materials. Finally, a new method of presenting volumetric strain versus applied stress data is shown and its relevance explained.
TL;DR: All of the alloys met the requirements in ADA specification no. 14 for base metal RPD alloys, but caution is recommended for clinicians and dental laboratories when performing clasp adjustments with all five alloys because of the substantial work hardening that can occur.
Abstract: Purpose This investigation compared the mechanical properties of three base metal casting alloys (Vitallium2, Neoloy N [Regular], and Regalloy T) for removable partial denture (RPD) frameworks with those for two base metal RPD alloys (Vitallium, Jelenko LG) whose mechanical properties had been previously reported.
Materials and Methods Plastic patterns with dimensions meeting ADA specification no. 14 requirements were used with appropriate casting investments to cast tensile test bars of the five alloys. Nine specimens of each alloy were loaded to failure, and the mechanical properties of modulus of elasticity, 0.1% yield strength, 0.2% yield strength, and tensile strength were obtained from five well-behaved load-elongation plots. Values of percentage elongation were also determined, along with Vickers hardness of the work-hardened alloys from polished cross-sections of fractured tensile specimens. The fracture surfaces for representative specimens of each alloy were examined with a scanning electron microscope.
Results Although the measured values of mechanical properties generally agreed with those reported by the manufacturers, differences found for Vitallium and Jelenko LG with previous investigations suggest that there may have been some changes in alloy compositions and processing by the manufacturers. The investment burnout procedure adopted for the plastic patterns and the present casting conditions may also have affected the mechanical properties of some alloys. Two alloys, Jelenko LG and Regalloy T, had mean values of percentage elongation exceeding 10%, but caution is recommended for clinicians and dental laboratories when performing clasp adjustments with all five alloys because of the substantial work hardening that can occur.
Conclusions In general, all of the alloys met the requirements in ADA specification no. 14 for base metal RPD alloys. Further research will be necessary to determine the relationships between the mechanical properties, particularly yield strength, rate of work hardening and percentage elongation, and the clinical requirements for these alloys.
TL;DR: In this article, the authors used large-grained material, for which the yield strength would be approximately the same as the lattice resistance, and subjected the material to a long, low temperature anneal to minimize the vacancy concentration.
Abstract: In the present study, the authors set out to determine whether a peak in the yield strength occurs in Fe-40Al. In order to observe the lattice properties more clearly, they used large-grained material, for which the yield strength would be approximately the same as the lattice resistance, and they subjected the material to a long, low temperature anneal to minimize the vacancy concentration. The results clearly indicate a peak in the yield strength at a temperature similar to that observed by Chang in directionally-solidified material of the same composition.
TL;DR: In this paper, the authors reported a dramatic increase in tensile ductility (from 13 to 21 to 60 pct) and a decrease in delamination tendency at the UHCS-brass interfaces as layer thickness was decreased.
Abstract: Laminated metal composites containing equal volume percentage of ultrahigh carbon steel (UHCS) and brass were prepared in three different layer thicknesses (750, 200, and 50 μm) by press- bonding and rolling at elevated temperature and were tensile tested at ambient temperature. A dramatic increase in tensile ductility (from 13 to 21 to 60 pct) and a decrease in delamination tendency at the UHCS-brass interfaces were observed as the layer thickness was decreased. The layer thickness effect on ductility is attributed to residual stress whose influence on delamination is decreased as the layer thickness is decreased. Suppression of delamination inhibits neck for- mation in the UHCS layers, allowing for extended uniform plasticity. For a given layer thick- ness, the tensile ductility decreases as the ratio of hardness of component layers is increased.
01 Jan 1993
TL;DR: In this paper, a technique to determine interlaminar tension strength, sigma(sub 3c) of a fiber reinforced composite material using a curved beam, was described, and the data sets fell into two categories: low strength corresponding to a macroscopic flaw related failure and high strength correspond to a microscopic fault related failure.
Abstract: This paper describes a technique to determine interlaminar tension strength, sigma(sub 3c) of a fiber reinforced composite material using a curved beam The specimen was a unidirectional curved beam, bent 90 degrees, with straight arms Attached to each arm was a hinged loading mechanism which was held by the grips of a tensile testing machine Geometry effects of the specimen, including the effects of loading arm length, inner radius, thickness, and width, were studied The data sets fell into two categories: low strength corresponding to a macroscopic flaw related failure and high strength corresponding to a microscopic flaw related failure From the data available, the loading arm length had no effect on sigma(sub 3c) The inner radius was not expected to have a significant effect on sigma(sub 3c), but this conclusion could not be confirmed because of differences in laminate quality for each curve geometry The thicker specimens had the lowest value of sigma(sub 3c) because of poor laminate quality Width was found to affect the value of sigma(sub 3c) only slightly The wider specimens generally had a slightly lower strength since more material was under high stress, and hence, had a larger probability of containing a significant flaw
TL;DR: In this paper, the mechanical properties of short fibre reinforced magnesium and magnesium RZ5 alloy metal matrix composites (MMCs) have been determined in tension and compression, and the data show that certain property values are highly dependent on the test method employed for their determination.
Abstract: The mechanical properties of short fibre reinforced magnesium and magnesium RZ5 alloy metal matrix composites (MMCs) have been determined in tension and compression. The data show that certain property values are highly dependent on the test method employed for their determination. In particular, values of ultimate strength are consistently greater in compression than in tension, and the MMCs are considerably more ‘deformable’ in compression. However, irrespective of the type of test method employed, the MMC materials exhibit higher Young's moduli, proof stresses, and ultimate strengths than the corresponding unreinforced materials, and much lower ductilities. This investigation also shows that compressive data appear to be affected by the aspect ratio of the test specimen. This effect is particularly pronounced when the length/diameter ratio is less than unity. The fracture behaviour of such specimens also differs from the fracture behaviour of specimens having higher length/diameter ratios.MST/1498
16 Mar 1993
TL;DR: In this article, the effect of carbon fibers on the tensile strength of a cement paste matrix was experimentally and analytically investigated, and a predictive model based on the rule of mixtures was developed.
TL;DR: In this paper, the authors present dynamic fatigue results using a two-point bend apparatus that can be programmed to operate in constant velocity, constant strain rate, and constant stress rate loading modes.
Abstract: Tho-point bending is a useful method for investigating the mechanical properties of optical fiber and has several advantages when compared to the traditional tensile test. However, the strength of the fiber is usually determined at constant faceplate velocity rather than at constant strain rate as in the uniaxial tensile test, and previous work casts doubt on the comparability of fatigue results obtained using different loading modes and hence on the reliability of the bending technique. This paper presents dynamic fatigue results using a two-point bend apparatus that can be programmed to operate in constant velocity, constant strain rate, and constant stress rate loading modes. These results, obtained for both bare and polymer-coated fused silica optical fiber, show no significant differences in the calculated fatigue parameters for the three loading modes and clearly indicate the reliability of the two-point bend method at constant faceplate velocity. The results, however, show that the obtained value of the stress corrosion susceptibility parameter, n, is dependent on the quantity used to define it, i.e., stress or strain to failure, because of the nonlinear elastic behavior of silica.
TL;DR: In this article, the tensile strength and stress-strain behavior under tensile stress in piezoelectric ceramics have been investigated with special emphasis on the effects of poling conditions.
Abstract: Fracture strength and stress-strain behavior under tensile stress in piezoelectric ceramics have been investigated with special emphasis on the effects of poling conditions. The materials used in this work are the commercial piezoelectric ceramics, PbZrO3-PbTiO3 (PZT) and BaTiO3. First, an attempt was made to evaluate the tensile strength properties of samples having a specially designed specimen geometry. In the actual tensile test, fracture did not occur at the gripping portion at all, indicating usefulness of the present tensile test method. Not only fracture strength, but also elastic properties, tensile modulus and Poisson's ratio, were evaluated. Second, an investigation was performed on the stress-strain behavior under tension in this material. As a result, stress-strain response under tension was confirmed to be nonlinear. The nonlinearity in the stress-strain relationship under compression loading has already been reported by some investigators. However, very little work has been done on the tensile stress-strain relationship studied in this paper. Third, acoustic emission monitoring was performed simultaneously during tensile tests, and thus the tensile failure process in piezoelectric ceramics was discussed.