Crack Extension Research Articles

Multi-Level Structural Enhancement Mechanism of the Excellent Mechanical Properties of Dung Beetle Leg Joint.

The multi-level structure is a strategy to enhance the mechanical properties of dung beetle leg joints. Under external loads, the microstructure facilitates energy dissipation and prevents crack extension. The macrostructure aids in transferring the load to more reliable parts. The connection established by the two hemispheres is present in the dung beetle leg joint. The micron-layered and nanoscale crystal structures further constitute the leg joint with excellent mechanical properties. The maximum compression fracture force is ≈101000 times the weight of the leg. Here, the structural design within the dung beetle leg joints and reveal the resulting mechanical response and enhancement mechanisms is determined. A series of beetle leg joints where the macrostructure and microstructure of the dung beetle leg provide mechanical strength at critical strains while avoiding catastrophic failure by transferring the load from the joint to the exoskeleton of the femur is highlighted. Nanocrystalline structures and fiber layers contribute to crack propagation of the exoskeleton. Based on this, the bionic joint with multi-level structures using resin and conducted a series of tests to verify their effectiveness is prepared. This study provides a new idea for designing and optimizing high-load joints in engineering.

Acoustic emission for exploring loading rate impact on type I fracture mechanism of engineering cementitious composites after subjected to sub-high temperature

To investigate the crack extension mechanism of engineered cementitious composite (ECC) after sub-high temperature. This paper studies the mode I fracture properties of ECC after sub-high temperatures (20 °C, 100 °C, 200 °C) at three strain rates (2 × 10-5s-1,10-4s-1,10-3s-1), and monitors the damage process in real-time by acoustic emission (AE) technology. Crack evolution and failure modes of ECC during loading are investigated by AE signal parameters. The results show that compared with 20 °C, the fracture energy of ECC increases after 100 °C, and decreases after 200 °C. The damage characteristics of ECC after 100 °C are similar to those at room temperature. Due to the bridging effect of the PVA fibers, their internal microcracks spread around from the tip of the prefabricated cracks. The percentage of shear type cracks gradually increases. The damage types are dominated by matrix cracking and fiber pull-out. While the PVA fibers deteriorated after 200 °C, the damage within the ECC was more concentrated, and the width of the fracture process zone was reduced. The crack types were dominated by tensile cracks. The failure mode was dominated by fiber pull-off and matrix cracking. Construction of an AE energy-based damage model. The b-value can reflect the whole process of crack evolution from multi-cracks to main cracks within ECC.

Initiation and growth of fatigue cracks in sheets with U-shaped notches in the first and mixed modes of fracture

Initiation and growth of fatigue cracks in sheets with U-shaped notches in the first and mixed modes of fracture

Quantifying the impact of geological and construction factors on hydraulic fracture dynamics in heterogeneous rock layers using the phase field method

Hydraulic fracturing, a pivotal practice for optimizing development in tight oil reservoirs, encounters challenges in accurately predicting propagation paths within heterogeneous rock formations. Existing phase models often overlook the influence of complex formations, especially in porous media with heterogeneous characteristics. Addressing this gap, we present a novel phase field method aligned with on-site practices. This innovative approach considers cracks, bedding planes, and faults as heterogeneous structures, integrating directional physical and mechanical properties. The key innovation lies in constructing assignment functions to characterize mechanical and seepage parameters of the rock matrix. Anchored in pore elasticity theory and the principle of energy minimization, we establish and validate a hydraulic coupled phase field model through plaster experiments. This model not only corrects the oversight of formation heterogeneity but also provides a comprehensive analysis of the impact of physical and construction parameters on crack propagation. The study extends to numerical simulation studies on three typical heterogeneous rock layers—natural fractures, bedding planes, and faults. Utilizing indicators like fracture pressure, crack extension length, and damage area, a random forest algorithm quantifies the degree of influence of each factor on fracturing. Our results underscore varying impacts from geological factors (natural fractures, bedding angle, stress difference, elastic modulus, matrix porosity, and permeability) and construction factors (cluster spacing, perforation length, fracturing fluid viscosity, displacement, well spacing, and perforation opening) on the fracturing effect of heterogeneous rock layers. In conclusion, our proposed phase field framework demonstrates predictive capability across diverse heterogeneous situations. This innovative model not only rectifies past oversights but also offers insights unattainable through traditional experimental testing, significantly advancing our understanding of hydraulic fracture dynamics.

Designing Ultratough Single-Network Hydrogels with Centimeter-Scale Fractocohesive Lengths via Inelastic Crack Blunting.

Fractocohesive length, defined as the ratio of fracture toughness to work of fracture, measures the sensitivity of materials to fracture in the presence of flaws. The larger the fractocohesive length, the more flaw-tolerant and crack-resistant the hydrogel. For synthetic soft materials, the fractocohesive length is short, often on the scale of 1 mm. Here, highly flaw-insensitive (HFI) single-network hydrogels containing an entangled inhomogeneous polymer network of widely distributed chain lengths are designed. The HFI hydrogels demonstrate a centimeter-scale fractocohesive length of 2.21cm, which is the highest ever recorded for synthetic hydrogels, and an unprecedented fracture toughness of ≈13300 J m-2 . The uncommon flaw insensitivity results from the inelastic crack blunting inherent to the highly inhomogeneous network. When the HFI hydrogel is stretched, a large number of short chains break while coiled long chains can disentangle, unwind, and straighten, producing large inelastic deformation that substantially blunts the crack tip in a plastic manner, thereby deconcentrating crack-tip stresses and blocking crack extension. The flaw-insensitive design strategy is applicable to various hydrogels such as polyacrylamide and poly(N,N-dimethylacrylamide) hydrogels and enables the development of HFI soft composites.

Synergistic crack inhibition by lamellar structure and graphene nanoplatelets in 2024 Al-GNPs/TC4 laminated metal composites

Al/Ti laminated metal composites (LMCs) benefit from a bionic laminate structure that allows for simultaneous strength and plasticity enhancement. However, the Al layer with lower strength is always the first to crack under stress, resulting in declining mechanical properties of the Al/Ti LMCs. In this study, 2024 Al-GNPs/TC4 LMCs were prepared by replacing the conventional Al or Al alloy layers with 2024 Al-GNPs composites. Its ultimate tensile strength of 757 MPa surpasses that of almost all other Al/Ti LMCs. The lamellar structure and GNPs were found to have a synergistic effect in enhancing the mechanical properties by inhibiting crack extension across and within the layers, respectively. The hindrance of crack extension by the lamellar structure is primarily due to strain delocalization in TC4, as confirmed by phase-field-crystal simulation. On the other hand, GNPs impede crack extension through passivation and deflection, which was revealed by molecular dynamics to be attributed to dislocation hindrance and load transfer. Furthermore, it was confirmed that the main factors affecting the formation of intermetallic compounds are diffusion coefficient and solid solubility. This work provides new insights for breaking the performance limits of LMCs.

Hydrogen-assisted cracking and damage tolerance of high-strength lath-martensite steel bars for structural applications

The paper addresses the hydrogen-assisted cracking and damage tolerance of high-strength lath martensite steel bars assessed from slow strain rate tensile tests. These were carried out on fatigue precracked specimens simultaneously charged with hydrogen in a standardized 20 % aqueous solution of ammonium thiocyanate at 50 °C and in air, at room temperature, for comparison. The fractographic analysis of the tested specimens showed the steel sensitivity to hydrogen uptake, which gives rise to the sub-critical extension of the pre-existing crack in two phases, initiation and growth, with both hydrogen-enhanced decohesion (HEDE) and hydrogen-enhanced localized plasticity (HELP) being synergically involved as damage mechanisms. Despite this, the damage tolerance behavior of the steel is highly satisfactory because the crack size causing the steel failure in tension slightly exceeds the theoretical limit of plastic collapse under combined tension and bending loading, regardless of the environment aggressiveness. Although H-assisted failure loads fit the theoretical limit loads, the fast propagation of the crack under constant load beyond the small-scale yielding regime could represent a real threat for the structural use of these steel bars in aggressive media unless the service loads are limited in accordance with such behavior.

Robust micro-nano hybrid aerogel derived from waste resources for thermal management and high-efficiency adsorption

Ultra-low density nanoaerogels as the lightest solid material have aroused extensive attention. However, lacking crack extension resistance limited their further development and application. Here, aramid and cellulose wastes were recycled to prepare high value-added nanofibers, which were further self-assembled to construct multilfunctional hybrid aerogels. In-situ growth of zeolitic imidazolate frameworks-8 (ZIF-8) on the cellulose nanofiber (CNF) created a robust skeleton. Flexible aramid nanofibers (ANF), as burgeoning building blocks were employed to inlay into the microscopic skeleton structure for establishing micro-nano double networks. Benefiting from the existence of multiscale networks, the maximum value in the compressive stress of S0, S1, S2 and S3 increased from 2.74 to 4.63, 5.19 and 6.61 MPa, respectively.Meanwhile, ANF-ZIF-8-CNF hybrid aerogels exhibited low thermal conductivity of 3.58–3.97 × 10-2 W/(m⋅K). The significant increase in the specific surface area (481.46 m2/g) endowed hybrid aerogels with high adsorption abilities for nitrogen (280.83 cm3/g), prussian blue (34.12 mg⋅g−1), rhodamine B (37.30 mg⋅g−1), DMF (25.13 g⋅g−1) and DMSO (15.48 g⋅g−1), respectively. This multiscale structural engineering strategy opens an avenue toward to upcycle waste resources into the next-generation high-performance nanoaerogels, showing huge application potential in thermal management, air purification and sewage treatment.

Dynamic evolution of crack fractal of polypropylene fiber reinforced geopolymer during flexural process

Crack mouth opening displacement (CMOD) is the most widely used parameter to evaluate the crack width changing process in concrete fracture research. However, it is difficult to accurately and comprehensively describe the multi-crack cracking characteristics of high-toughness concrete with only crack width. This paper investigates the dynamic evolution of the fractal dimension (FD) of surface cracks on polypropylene fiber-reinforced geopolymer (PFRG) during flexural process. The box counting method was used to calculate the FD of cracks in the segmentation images that were generated by deep learning. Crack FD at the peak load and the fracture failure load could be used as indicators of deflection hardening behavior, with threshold values of 0.83 and 0.86, respectively. Crack development can be divided into four stages based on load, FD, CMOD, and energy capacity with time: elastic segment, internal crack development segment, surface crack extension segment, and crack destabilization segment. FD shows an obvious exponential increase in the surface crack extension segment and crack destabilization segment, and the changing trend is basically parallel with the load in the surface crack extension segment. The FD of peak load and fracture failure load showed a trend of increasing and then decreasing as the fiber factor was increased. The FD value peaks at 585 when W/B = 0.35 and at 252 when W/B = 0.38. To achieve the best stress diffusion and crack propagation process and achieve the toughening objective, it is necessary to reasonably match the fiber factor and matrix strength.

A macro-mesoscopic constitutive model for porous and cracked rock under true triaxial conditions

The complex mechanical and damage mechanisms of rocks are intricately tied to their diverse mineral compositions and the formation of pores and cracks under external loads. Numerous rock tests reveal a complex interplay between the closure of porous defects and the propagation of induced cracks, presenting challenges in accurately representing their mechanical properties, especially under true triaxial stress conditions. This paper proposes a conceptualization of rock at the mesoscopic level as a two-phase composite, consisting of a bonded medium matrix and frictional medium inclusions. The bonded medium is characterized as a mesoscopic elastic material, encompassing various minerals surrounding porous defects. Its mechanical properties are determined using the mixed multi-inclusion method. Transformation of the bonded medium into the frictional medium occurs through crack extension, with its elastoplastic properties defined by the Drucker–Prager yield criterion, accounting for hardening, softening, and extension. Mori–Tanaka and Eshelby’s equivalent inclusion methods are applied to the bonded and frictional media, respectively. The macroscopic mechanical properties of the rock are derived from these mesoscopic media. Consequently, a True Triaxial Macro-Mesoscopic (TTMM) constitutive model is developed. This model effectively captures the competitive effect and accurately describes the stress-deformation characteristics of granite. Utilizing the TTMM model, the strains resulting from porous defect closure and induced crack extension are differentiated, enabling quantitative determination of the associated damage evolution.

Fracturing and Dome‐Shaped Surface Displacements Above Laccolith Intrusions: Insights From Discrete Element Method Modeling

AbstractInflation of viscous magma intrusions in Earth's shallow crust often induces strain and fracturing within heterogeneous host rocks and dome‐shaped ground deformation. Most geodetic models nevertheless consider homogeneous, isotropic, and linear‐elastic media wherein stress patterns indicate the potential for failure, but without simulating actual fracturing. We present a two‐dimensional Discrete Element Method (DEM) application to simulate magma recharge in a pre‐existing laccolith intrusion. In DEM models, fractures can propagate during simulations. We systematically investigate the effect of the host rock toughness (resistance to fracturing), stiffness (resistance to deformation) and the intrusion depth, on intrusion‐induced stress, strain, displacement and spatial fracture distribution. Our results show that the spatial fracture distribution varies between two end‐members: (a) for high stiffness or low toughness host rock or a shallow intrusion: extensive cracking, multiple vertical surface fractures propagating downward and two inward‐dipping highly cracked shear zones that connect the intrusion tip with the surface; and (b) for low stiffness or high toughness host rock or a deeper intrusion: limited cracking, one central vertical fracture initiated at the surface, and two inward‐dipping fractures at the intrusion tips. Abrupt increases in surface displacement magnitude occur in response to fracturing, even at constant magma injection rates. Our modeling application provides a novel approach to considering host rock mechanical strength and fracturing during viscous magma intrusion and associated dome‐shaped ground deformation, with important implications for interpreting geodetic signals at active volcanoes and the exploitation of geothermal reservoirs and mineral deposits.

Mode of Action of Calcium in Reducing Macrocracking of Sweet Cherry Fruit

Rain cracking (hereinafter referred to as macrocracking) severely impacts the production of sweet cherry (Prunus avium). Calcium (Ca) sprays can reduce macrocracking, but the reported responses to Ca sprays are variable and inconsistent. The objective of this study was to establish the physiological mechanism through which Ca reduces macrocracking in sweet cherry fruit. Six spray applications of 50 mM CaCl2 had no effect on macrocracking (assessed using a standardized immersion assay) despite a 28% increase in the Ca-to-dry mass ratio. Similarly, during another experiment, there was no effect of up to nine Ca sprays on macrocracking, although the Ca-to-dry mass ratio increased as the number of applications increased. In contrast, CaCl2 spray applications during simulated rain (in a fog chamber) significantly reduced the proportion of macrocracked fruit. Additionally, immersion of fruit in CaCl2 decreased macrocracking in a concentration-dependent manner. Monitoring macrocrack extension using image analysis revealed that the rate of macrocrack extension decreased markedly as the CaCl2 concentration increased. This effect was significant at concentrations as low as 1 mM CaCl2. Decreased anthocyanin leakage, decreased epidermal cell wall swelling, and increased fruit skin stiffness and fracture force contributed to the decrease in macrocracking. There was no effect of CaCl2 on the cuticle deposition rate. Our results demonstrated that Ca decreased macrocracking when applied to a wet fruit surface either by spraying on wet fruit or by incubation in solutions containing CaCl2. Under these circumstances, Ca had direct access to the cell wall of an extending macrocrack. The mode of action of Ca in reducing macrocracking is primarily decreasing the rate of crack extension at the tip of a macrocrack.

Application of a hierarchical quadrature element method to interface crack analysis in bi-material systems

This paper presents an extension of the hierarchical quadrature element method (HQEM) with p-convergence to evaluating fracture mechanical parameters of bi-material interface cracks. The numerical implementation of HQEM in combination with the virtual crack closure method (VCCM) is comprehensively illustrated, and the formulas for calculating the strain energy release rate (SERR) are rederived. The relationship between components of SERR and the complex stress intensity factors (SIFs) is established. In addition, the effectiveness of an auxiliary parameter related to the dual energy release rates in measuring the accuracy of the present method is examined.The feasibility of applying HQEM to the interface crack problems is demonstrated by investigating the benchmark problem of an infinite bi-material plate with a central interface crack. Two loading cases are considered, including pure tensile loading and mixed tensile-shear loading. The influence of the crack tip element size Δa on the convergence characteristics and computational accuracy of fracture parameters is quantitatively investigated to provide guidance for choosing the most reasonable value of Δa. Numerical results show that even with very coarse meshes, together with a virtual crack extension consisting of only one element, HQEM yields highly accurate results for the total SERR and the complex SIFs, making it suitable for complex, large-scale interface crack problems in dissimilar media.

Toughness modification of SBS/CRMA on epoxy asphalt: curing behaviour and low-temperature cracking characteristic analysis

ABSTRACT The limited utilisation of epoxy asphalt primarily stems from its inherent brittle cracking behaviour. This investigation aims to mitigate this issue by introducing styrene–butadiene-styrene/crumb rubber modified asphalt (SBS/CRMA). Furthermore, this research assesses the influence of SBS/CRMA on the curing behaviour of epoxy asphalt (EA) and the low-temperature fracture characteristics of epoxy asphalt concrete (EAC). The curing behaviour of EA was systematically examined using diverse analytical techniques, including attenuated total reflectance fourier transform infrared spectroscopy (ATR-FTIR), rotational viscosity, and non-isothermal curing kinetics analysis. Notably, SBS/CRMA expedites the curing process of epoxy asphalt, possibly attributed to the amine constituents in the crumb rubber, which acts as catalyst. Subsequently, the study scrutinised the fracture characteristics of EAC through the application of the semicircle bending (SCB) test and acoustic emission (AE) methodology. The results substantiate that SBS/CRMEAC imparts a proficient toughening effect, underpinned by an augmented stress relaxation capacity due to the reinforcing influence of elastomers such as crumb rubber and SBS. The fracture process was delineated into three distinct stage and the AE signal in matrix epoxy asphalt (MEA) exhibited concentration during the macroscopic crack extension and final fracture stages. In stark contrast, SBS/CRMEAC exhibited a uniform distribution and showcased ductile fracture characteristics.

Study of Deformation and Fault Mechanisms in Bedding-Locked Rock Slope

In geotechnical engineering, a bedding slope often leads to geological disasters, particularly in the case of bedding-locked rock slopes. This study focuses on a typical bedding-locked rock slope in western Henan Province, China. The deformation and fault characteristics were examined through the development of laboratory analogue experiments which allowed for the analysis of the physical and mechanical properties of the rock slope when subjected to a load. The deformation and faulting mechanisms of the slope were studied through the application of different strength loads to the slope model, as well as through the combination of its physical properties. The deformation and fault process were then simulated through the application of numerical modeling. The results reveal that the upper part of the slope features a linear slip surface, while the lower part features a circular arc slip surface, resulting in “linear + circular arc” damage geometry and a relatively flat shear surface. Maximum and minimum lateral displacement occur around the top and the foot of the slope, respectively, leaving the intermediate values at the middle. The shear strength is greater at the locking section, with the highest value found at the foot of the slope, followed by the middle and the top. The evolution of slope deformation can be divided into three stages: the loose deformation stage at the slope top and back; the stage of crack development, extension, and interlayer misalignment; and the stage of complete through crack formation and complete instability damage of the slope. Thus, the process of the deformation and damage of a rocky slope under loading conditions can be described as follows: load-induced loosening and deformation at the top and back of the slope, crack development, expansion, and interlayer misalignment, as well as tension crack expansion at the foot of the slope. The latter can expand and intensify interlayer misalignment, leading to the destruction of the locking section and ultimately causing the destabilization of the entire slope.

Polypropylene Fiber’s Effect on the Features of Combined Cement-Based Tailing Backfill: Micro- and Macroscopic Aspects

In undercut-and-fill mining, backfills show weak tensile strength and poor ductility properties since they act as artificial pillars to support stope roofs. Hence, the enhancement of the stability of mining structures and backfills is a crucial requisite for underground mining backfill operations. This study addresses the reinforcing effect of polypropylene (PP) on the strength features of combined cement-based tailing backfill (CCTB) with varied cement/tail ratios (c/t: 1:8 to 1:4) at both macroscopic and microscopic levels. Fill specimens containing a fixed solid content of 70 wt% were reinforced with fiber (0.6 wt%) and with no fiber (classified as a reference sample). They were then cast in mold sizes of 160 × 40 × 40 mm3, and cured for 7 days. Following curing, some experiments covering three-point bending assisted by DIC and SEM were performed to inspect the microstructure and strength features of CCTB. The results illustrate that the flexural strength of fiber-oriented CCTB increases along with the c/t fraction, but it is not greater than that of specimens with a high c/t fraction without fiber. Adding PP fiber, the peak deflection of CCTB specimens was improved, and the increment of peak deflection increased linearly with rising c/t fraction, enhancing CCTB’s bending characteristics. CCTB damage starts from the bottom to the middle, and the main cause of the damage is the stress distribution at the lowest section. The addition of fiber to CCTBs increases the ability to dissipate energy, which helps to hinder crack extension and prevent brittle damage from occurring. The microstructure shows that AFt and CSH were key hydrate materials in CCTB. As a result, this study develops the security of mining with backfill and helps to determine its design properties for safe production inputs and sustainable filling operations.

A new algorithm and damage index for detection damage in steel girders of bridge decks using time-frequency domain and matching methods

Damage identification, especially in the early stages, is one of the most important factors in preserving and maintaining structures and infrastructures. Structural Damage can lead to adverse and unwanted changes in the system. Unless these damages are identified and fixed on time, they gradually worsen, which may eventually lead to negative effects on the mechanism of the structure. For example, one of the most common types of damage in all types of structures is cracks causing changes in the characteristics and qualifications of the structures including reducing the stiffness and increasing the damping. The structure may experience significant problems if the crack extension increases. Changes and reductions in the cross-sectional area, changes in the characteristics and qualifications of the materials used, damage in the connections, or boundary conditions are considered to be among the other structural damages. Changes in the construction of the structure can cause changes in the dynamic behavior of the structure, too. In this research, a new algorithm to identify damages in the steel girders of the bridge decks has been presented. Based on this algorithm, the response signals of the steel girder are recorded and the reported signals are processed by Bern-Jordan time-frequency distribution and, finally time-frequency matrices are calculated. Then, the damage is identified and its location is determined by using the proposed damage index (C-Index). In addition, the proposed algorithm has been evaluated on the College Bridge. The analytical model of the College Bridge was designed based on the as-built details, field inspections, and material strength tests. To conduct a comprehensive evaluation, 10 different damage scenarios were considered. The results obtained from this research show that the proposed damage index can identify the damage and its location in steel girders with a high level of accuracy.

Thermal treatment effects on rock fracture behaviour under three loading modes: A comparative analysis of granite and mudstone

Temperature and thermal damage have a major impact on the behaviour of fractures in the earth’s crust. For deep earth engineering such as underground coal gasification, geothermal energy extraction, and nuclear waste repositories, developing fracture criteria governing the propagation of fractures under thermal effect is crucial. As a result, the ability of stress, energy, and strain-based fracture criteria to predict rock fracture behavior both before and after thermal treatment is assessed in this paper considering two rock types; granite, and mudstone, which are very different from one another in terms of their mineralogical composition and mechanical properties. The overall findings showed that the energy-based criterion was more effective in predicting fracture parameters both before and after thermal treatment than the stress and strain-based criteria. Specifically, after thermal treatment at 500 °C for the granite, and at any temperature for the mudstone, the strain-based criterion was no longer valid. It was found that the temperature and loading mode have a significant impact on the granite’s transition from brittle to ductile, where this transition can occur at an approximated temperature of 460 °C. Meanwhile, an increase in brittleness with rising temperature was noted in mudstone. Moreover, the Fracture Process Zone (FPZ) size was predicted by the energy-based criterion to be greater than that predicted by stress and strain-based criteria. It was found that the FPZ size is proportional to the brittleness degree of the two rock types, which is considerably impacted by thermal treatment. In addition, this study discusses several critical areas in rock fracture mechanics in the presence of thermal effects including fracture envelopes under mixed mode loading I/II, fracture stress, and initial crack extension angle. All of these are of high importance in assessing the safety and stability of rock structures in the presence of thermal effects.

Microcrack behavior in bone: Stress field analysis at osteon cement line tips.

Bone microstructure governs microcrack propagation complexity. Current research, relying on linear elastic fracture mechanics, inadequately considers authentic multi-level structures, like cement lines and osteons, impacting stress intensity at cracks. This study, by constructing models encompassing single or multiple osteons, delves into the influence of factors like crack length, osteon radius, and modulus ratio on the stress intensity factor at the crack tip. Employing a fracture mechanics phase-field approach to simulate crack propagation paths, it particularly explores the role of cement lines as weak interfaces in crack extension. The aim is to comprehensively and systematically elucidate the critical factors of bone microstructure in the context of crack propagation.

Experimental study of the damage characteristics of rocks containing non-penetrating cracks under cyclic loading

The damage evolution process of non-penetrating cracks often causes some unexpected engineering disasters. Gypsum specimens containing non-penetrating crack(s) are used to study the damage evolution and characteristics under cyclic loading. The results show that under cyclic loading, the relationship between the number of non-penetrating crack(s) and the characteristic parameters (cyclic number, peak stress, peak strain, failure stress, and failure strain) of the pre-cracked specimens can be represented by a decreasing linear function. The damage evolution equation is fitted by calibrating the accumulative plastic strain for each cycle, and the damage constitutive equation is proposed by the concept of effective stress. Additionally, non-penetrating cracks are more likely to cause uneven stress distribution, damage accumulation, and local failure of specimen. The local failure can change the stress distribution and relieve the inhibition of non-penetrating crack extension and eventually cause a dramatic destruction of the specimen. Therefore, the evolution process caused by non-penetrating cracks can be regarded as one of the important reasons for inducing rockburst. These results are expected to improve the understanding of the process of spalling formation and rockburst and can be used to analyze the stability of rocks or rock structures.