Full Curves Research Articles

Axial Compression Damage Model and Damage Evolution of Crumb Rubber Concrete Based on the Energy Method

The current constitutive model and damage evolution law of crumb rubber concrete (CRC) were obtained by fitting and changing parameters based on the normal concrete model. However, this model does not accurately reflect the characteristics of the material. In this paper, we studied the energy dissipation in the failure process of CRC to derive the constitutive model and damage evolution law of CRC based on the energy method. Four substitution rates of 5%, 10%, 15%, and 20% were selected, and the rubber concrete prism was prepared by replacing the natural fine aggregate with the same volume of crumb rubber aggregate. After that, uniaxial compressive tests were conducted. The energy lost due to the damage was calculated and analyzed, and the energy method was used to establish the damage evolution law and damage model of the crumb rubber concrete. The results demonstrated that the Guo Zhenhai damage model, which is based on the energy method, can more effectively explain the crumb rubber concrete stress–strain full curve, and the energy consumed as a result of the damage exhibits a growing and then reducing pattern with the increase in rubber doses. When the energy-based method is used, the Guo Zhenhai damage evolution model is similar to the damage evolution law calculated using the SIR damage evolution model. During uniaxial compression damage, rubber concrete with various rubber dosages demonstrated varying energy absorption in different deformation phases. When the rubber particle content was 10%, the energy absorption capacity of the specimen was 6.9% higher than that of normal concrete.

Predicting bovine daily milk yield by leveraging genomic breeding values

The main goal of this work, conducted on a herd of 502 Holstein cows situated in Italy, is to propose a machine learning-based approach to forecast the individual bovine daily milk production by explicitly leveraging genotypic information. As part of our study, we also evaluated the importance in the prediction of genotypic and phenotypic variables usually available within herd. The methodology we propose is based on two consecutive models: a genomic prediction one to calculate the animal’s genomic breeding value from marker data, followed by a feed forward neural network combining such additive genetic effect and the environmental features (parity, days in milk, age at calving in months, month of calving) for milk yield forecasting. In particular, we both assess the inclusion of genomic breeding values calculated within herd or provided by the breeders’ association, discovering that the latter ones allow for better final predictions. The results of our model outperform the ones by a linear mixed model with the same inputs on average, day by day and at the individual level. Moreover, we propose a problem formulation that also leverages additional factors partially controllable by breeders: in this case, features such as the number of milkings and the concentrate consumption inside the automatic milking system prove to highly impact on the final prediction, and hence on milk production. To the best of our knowledge, the proposed problem formulation based on genomic breeding values is a novelty in the individual bovine milk yield machine learning forecasting literature. Given the low genotyping costs and the availability of a larger number of environmental features in farms equipped with a wide range of sensors, as automatic milking systems, our solution can support breeders’ herd management and animal monitoring, thanks to the possibility to forecast the full lactation curve in advance even for primiparous bovines and newborn calves. With this work, we successfully achieve our objectives of including genomic information in bovine milk yield machine learning-based forecasting, thus improving the performance on this task, and of evaluating the impact on prediction of common genotypic and phenotypic information available to breeders.

Experimental study on the seismic performance of concrete-filled steel tube columns with a multiple-chamber round-ended cross-section

Reinforced concrete bridge piers with round-ended sections are susceptible to bending, bending–shear, and shear failure after earthquakes in high-intensity areas, thus necessitating improved seismic performance. This study introduced a novel design for a concrete-filled steel tube (CFST) column, featuring a multi-chambered, round-ended cross-section. The use of longitudinal and transverse stiffeners divided the column section into distinct chambers, thereby enhancing the seismic performance of the columns. A total of 12 groups of static tests were performed to examine the effect of chamber layout, axial compression ratio, and aspect ratio on columns’ hysteresis behavior, and the hysteresis curves, skeleton curves, failure modes, stiffness degradation, ductility, and energy dissipation capacity were obtained. Results demonstrated the favorable seismic performance of composite columns. Additionally, an increase in chambers led to a full hysteresis curve, enhancing bearing and energy dissipation capacities. The displacement ductility coefficient (μ) ranged between 3.88 and 7.45, and the design parameters have minimal influence on the stiffness degradation of the composite beam. Based on the results, the long and short sides of the CFST columns with a large length–width ratio should be arranged to be relatively close in length.

Shaking-Table Test and Finite Element Simulation of a Novel Friction Energy-Dissipating Braced Frame

To enhance the effect of seismic mitigation in medium-sized buildings, this study introduced a novel friction damper within a braced frame, forming a friction energy-dissipating braced frame (FDBF). The seismic reduction mechanism of the FDBF was examined, and its performance was evaluated through shaking-table tests and finite element simulations. The hysteresis performance of the novel damper was assessed through low-cycle repeated loading tests, which yielded predominantly rectangular and full hysteresis curves, exemplifying robust energy dissipation capacity. The shaking-table tests of the FDBF indicated significant modifications in the dynamic characteristics of the original frame structure, which notably reduced the natural vibration period and enhanced the damping. Additionally, the FDBF remarkably reduced both acceleration and displacement responses during seismic excitation. Optimizing the orientation of the energy dissipation brace significantly improved seismic reduction efficiency. A dynamic time history analysis, employing finite element software, was conducted on the FDBF equipped with a friction energy dissipation brace at each level. Comparative analysis with both the moment-resistant frame and ordinary braced frame revealed that the FDBF substantially lowered the peak acceleration at the apex of the structure, achieving a reduction rate of 40–50%. Under both design and rare earthquake conditions, the FDBF demonstrated superior seismic mitigation capabilities, especially under rare earthquakes. Future studies should investigate various structural types with energy dissipation braces at different levels to identify the most efficient layout for the novel friction energy dissipation brace, thereby guiding relevant engineering practices.

Determination of output factor for CyberKnife using scintillation dosimetry and deep learning

Objective. Small-field dosimetry is an ongoing challenge in radiotherapy quality assurance (QA) especially for radiosurgery systems such as CyberKnifeTM. The objective of this work is to demonstrate the use of a plastic scintillator imaged with a commercial camera to measure the output factor of a CyberKnife system. The output factor describes the dose on the central axis as a function of collimator size, and is a fundamental part of CyberKnife QA and integral to the data used in the treatment planning system. Approach. A self-contained device consisting of a solid plastic scintillator and a camera was build in a portable Pelicase. Photographs were analysed using classical methods and with convolutional neural networks (CNN) to predict beam parameters which were then compared to measurements. Main results. Initial results using classical image processing to determine standard QA parameters such as percentage depth dose (PDD) were unsuccessful, with 34% of points failing to meet the Gamma criterion (which measures the distance between corresponding points and the relative difference in dose) of 2 mm/2%. However, when images were processed using a CNN trained on simulated data and a green scintillator sheet, 92% of PDD curves agreed with measurements with a microdiamond detector to within 2 mm/2% and 78% to 1%/1 mm. The mean difference between the output factors measured using this system and a microdiamond detector was 1.1%. Confidence in the results was enhanced by using the algorithm to predict the known collimator sizes from the photographs which it was able to do with an accuracy of less than 1 mm. Significance. With refinement, a full output factor curve could be measured in less than an hour, offering a new approach for rapid, convenient small-field dosimetry.

Joint multi-contrast CT for edge illumination X-ray phase contrast imaging using split Barzilai-Borwein steps.

Edge illumination (EI) is an X-ray imaging technique that, in addition to conventional absorption contrast, provides refraction and scatter contrast. It relies on an absorption mask in front of the sample that splits the X-ray beam into beamlets, which hits a second absorption mask positioned in front of the detector. The sample mask is then shifted in multiple steps with respect to the detector mask, thereby measuring an illumination curve per detector element. The width, position, and area of this curve estimated with and without the sample in the beam is then compared, which ultimately provides absorption, refraction, and scatter contrast for each detector pixel. From the obtained contrast sinograms, three contrast tomograms can be computed. In summary, conventional EI relies on a two-stage process comprised of a computational and time intensive contrast retrieval process, followed by tomographic reconstruction. In this work, a novel joint reconstruction method is proposed, which utilizes a combined forward model to reconstruct the three contrasts simultaneously, without the need for an intermediate contrast retrieval step. Compared to the state-of-the-art, this approach reduces reconstruction times, as the retrieval step is skipped and allows a much more flexible acquisition scheme, as there is no need to sample a full illumination curve at each projection angle. The proposed method is shown to improve reconstruction quality on subsampled datasets, enabling the reconstruction of three contrasts from single-shot datasets.

State of Health Estimation Procedure for Lithium-Ion Batteries Using Partial Discharge Data and Support Vector Regression

Battery aging is a complex phenomenon, and precise state of health (SoH) monitoring is essential for effective battery management. This paper presents a data-driven method for SoH estimation based on support vector regression (SVR), utilizing features built from both full and partial discharge capacity curves, as well as battery temperature data. It provides an in-depth discussion of the novel features constructed from different voltage intervals. Moreover, three combinations of features were analyzed, demonstrating how their efficacy changes across different voltage ranges. Successful results were obtained using the full discharge capacity curves, built from the full interval of 2 to 3.4 V and achieving a mean R2 value of 0.962 for the test set, thus showcasing the adequacy of the selected SVR strategy. Finally, the features constructed from the full voltage range were compared with ones built from 10 small voltage ranges. Similar success was observed, evidenced by a mean R2 value ranging between 0.939 and 0.973 across different voltage ranges. This indicates the practical applicability of the developed models in real-world scenarios. The tuning and evaluation of the proposed models were carried out using a substantial dataset created by Toyota, consisting of 124 lithium iron phosphate batteries.

Experimental study and constitutive modelling of wire arc additively manufactured steel under cyclic loading

Wire arc additive manufacturing (WAAM) is an efficient and cost-effective method of metal 3D printing that is well suited to structural engineering applications. Fundamental test data on the mechanical properties of WAAM materials, especially under cyclic loading, are however lacking. To address this, an experimental study into the cyclic behaviour of WAAM steel plates has been undertaken and is reported herein. Following geometric and quasi-static mechanical characterisation, a total of 40 as-built and machined coupons were tested under different cyclic loading protocols. Key results from the tests, including the full hysteresis curves, are presented and discussed. A cyclic constitutive model allowing for a yield plateau and the degradation of elastic modulus is proposed and validated against the test data. It is shown that the examined WAAM steel exhibited cyclic hardening behaviour dependent on the strain amplitude and strain history. The elastic modulus of the WAAM material was found to decrease in the first few cycles and then remain stable with increasing accumulated plastic strain. Good energy dissipation performance was also observed, indicating the potential of WAAM steels for seismic applications.

Influencing Factors of Porosity and Strength of Plant-Growing Concrete.

A standardized preparation process is proposed in this study for achieving optimal strength and vegetative properties in vegetated concrete, using Yunnan red soil as a growth substrate for plants. The porosity of vegetated concrete is a crucial factor influencing plant growth, while compressive strength is a significant mechanical property. To assess the strength and porosity of vegetated concrete, different design porosities (22%, 24%, 26%, 28%) and cement-to-aggregate ratios (4, 5, 6, 7) were utilized in the preparation of vegetated concrete samples. The shell-making and static-pressure-molding methods were optimized for specimen preparation. Analyzing the stress-strain full curve characteristics of vegetation-type concrete under different influencing factors, an in-depth investigation into its failure mechanism was conducted. It was determined that the design porosity and cement content significantly impact the concrete's performance, particularly in terms of 30-day compressive strength and effective porosity. Furthermore, an increase in the fly ash ratio led to an increase in porosity and a decrease in compressive strength, providing a certain guidance for optimizing concrete performance. Comparative analysis through vegetation experiments revealed that black rye grass exhibited favorable growth adaptability compared to other grass species.

Seismic Behavior of T-Shaped Concrete-Filled Steel Tubular Column to Steel Beam Joints with Side Plates

This study investigates the seismic behavior of the T-shaped concrete-filled steel tubular (CFST) column to steel beam joints, aimed at expanding their applicability in areas with high-seismic fortification intensity. A construction form of T-shaped CFST column to steel beam joint with side plates is presented. The variables studied in these experiments include the side plate length, the axial compression ratio, the presence of side plates, and the presence of binding bars. The force mechanism, failure modes, load–displacement curves, strength, stiffness, ductility, and energy dissipation capacity of seven specimens were evaluated under low-cycle reciprocating load. The experimental results demonstrate that the joints of side plates show a full hysteresis curve, with the ductility coefficient ranging from 1.67 to 2.49, and the equivalent viscous damping coefficient between 0.147 and 0.234. The joint panel zone displays strong deformation and energy dissipation capacity. The inclusion of side plates and binding bars improves the seismic behavior of the joint. The setting of side plates enables the formation of a plastic hinge on the steel beam, creating a beam hinge failure mechanism and satisfying the seismic design principle of “strong column and weak beam, strong joint and weak member” as required by the building structures.

3D mesoscale modelling of recycled aggregate concrete

Mesoscale modelling is a promising tool to analyse the phenomenological causes of mechanical failure of recycled aggregate concrete (RAC). Most mesoscale models of RAC are two-dimensional (2D) and 3D models are lacking. This prevents the full understanding of the behaviour of each mesoscopic phase. This paper presents a 3D model of RAC and analyses its mechanical behaviour based on mesoscale phenomena. The analyses concern three types of tests carried out in concrete specimens: uniaxial compressive, uniaxial tensile and splitting tensile strength tests. The mechanical response and fracture behaviour of each mesoscopic phase is analysed in relation to the response of RAC specimen. The comparisons between uniaxial behaviour of 3D and 2D modelling as well as between uniaxial and splitting tensile behaviour of RAC are presented. The main findings of the paper are: (1) the full curve of uniaxial stress-strain response from 3D modelling is comparable to that from 2D modelling for RAC (therefore, 2D models are validated for RAC modelling); (2) the overall behaviour of the concrete elements remains elastic regardless of the fracture development in the ITZ and attached mortar of recycled aggregates until damage propagates to the new mortar matrix; (3) a relationship between modelled uniaxial and splitting strength of RAC is established and validated.

Improved Period Variations of 32 Contact Binaries with Rapidly Decreasing Periods in the Galactic Bulge

We present detailed analyses of updated eclipse timing diagrams for 32 contact binary merger candidates in the Galactic bulge. The photometric data was obtained from 2016 to 2021 using the Korea Microlensing Telescope Network with the 1.6 m telescopes located at three southern sites (CTIO, SAAO, and SSO). The times of minimum lights were determined by applying the binary-star model to full light curves created at half-year intervals from the observations. The orbital period variations of the binary systems were analyzed using the O − C diagrams from our new timings with the others published in the literature, which are based on the OGLE observations from 2001 to 2015. As results, the orbital periods and period-decreasing rates of 32 binary systems were located to be in the ranges of 0.370 to 1.238 days and from −3.0 to −13.1 × 10−6 day yr−1, respectively. Out of these stars, 24 systems show a combination effect of a parabola and a light travel time caused by a third body, and their outer orbital periods are in the range of 9.1–26.5 yr. We propose that all of our merger candidates need additional monitoring observations to study a luminous-red nova progenitor.

Creep and stress relaxation experiments of 1960-grade high-strength steel wire at elevated temperatures

With the increasing spacing of large-span structures, the application of ultra-high-strength steel wire with a strength approaching or exceeding 2000 MPa is rapidly expanding. However, the related research on its creep and stress relaxation behaviour is still limited. In this paper, a total of 30 high-temperature creep tests and 31 high-temperature stress relaxation tests were conducted on 1960-grade high-strength steel wire (1960-HSSW) with a diameter of 5.0 mm. The full process creep strain curves were obtained by reinserting and resetting the high-temperature extensometer. The maximum creep strain measured was 50.67 %. The creep and stress relaxation curves of different high-strength steel wires (steel strands) were compared, revealing significant variations in mechanical properties among different steel wires. The steady-state creep rate and high-temperature creep rupture critical stress ratio of the 1960-HSSW were given. Especially, the critical stress ratio became lower than the yield strength reduction coefficient at temperatures exceeding 400 °C and it indicated that the 1960-HSSW could undergo creep rupture before yield. The stress relaxation coefficient was introduced to consider the stress relaxation of 1960-HSSW. Stress relaxation curves for the 1960-HSSW were provided at temperatures ranging from 100 to 550 °C. Moreover, based on the microstructure observed under transmission electron microscopy, it was found that damage occurred in the 1960-HSSW after exposure to 300 °C. Therefore, a critical temperature of 300 °C was recommended for the fire protection of 1960-HSSW, which could be the theoretical support for its fire protection design. Additionally, a high-temperature creep prediction model, which includes expressions for the termination time, was established for the 1960-HSSW. As a result, a conservative prediction of the high-temperature creep for the 1960-HSSW was provided. Moreover, A stress relaxation coefficient model was also provided. The predicted results of the aforementioned models were in good agreement with experimental results.

Methyl oleate for plant protection products formulations: Enzymatic synthesis, reaction kinetics and application testing

This study presents a solvent-free enzymatic approach for the synthesis of fatty acid methyl esters (FAMEs), such as methyl oleate, for their application as adjuvant in plant protection products (PPP) formulations. The direct esterification between free fatty acid and methanol was optimized to achieve 98% acid conversion. The kinetics of this conversion was accurately described by a simple second order mechanism and non-linear regression was applied to calculate the rate constants of the forward and backward reactions based on full progress curves data. The rate constant of the forward reaction (synthesis) was one order of magnitude higher than the backward reaction (hydrolysis) and favored formation of the target methyl ester product, rendering the removal of water unnecessary. Enzymatically synthesized methyl oleate was benchmarked against the chemically synthesized compound, showing matching results in terms of stability, spreadability and emulsifying capacity in plant care formulations. The enzymatic synthesis of FAMEs under solvent free conditions allows to achieve a safer and more sustainable character for carrier solvents in PPP formulations.

Determination of performance characteristics using FEA-analytical for outer rotor BLDC motor

This paper presents an analytical approach to determine the performance characteristics of an outer rotor Brushless DC (BLDC) motor using finite element analysis (FEA). An accurate performance characteristic is a crucial deliverable during the early motor design process in order to minimize the cost of change while delivering a feasible design to the application. There are several popular methods to determine motor performance, including template-based software as well as FEA. However, these two methods have limitations in terms of geometry and time. Therefore, this paper proposes that the limitations can be addressed by using a combination of FEA and mathematical equations. First, the optimum motor design is determined using an FEA analytical approach. Second, the torque constant <em>K</em><sub>T</sub>, is derived from the FEA results and followed by performance curve generation using the mathematical equation of speed, current, and output power in terms of torque function. Finally, the outcome results are verified against the motor requirements, including an assessment of maximum speed, stall current, and maximum output power. In conclusion, this research introduces a methodology for determining full curve motor performance prior to prototype fabrication. The leverage benefit could be gained through robust design and low-cost development.

Research on hysteretic performance of a semi-rigid energy dissipation connection for precast cladding panels

A novel semi-rigid energy dissipation connection (SEDC), capable of transitioning the precast cladding panel from a rigid connection to a flexible connection with the primary structure as the seismic action increases, is proposed in the present study. The combination of the bending part and friction part endows the connection with the ability to provide adjustable sliding force and sufficient energy dissipation for the precast cladding panel. The design methods of SEDC, including the elastic stiffness, the yield force, the yield displacement, and the bear capacity, are proposed, followed by a coordinated design method between the precast cladding panels and the primary structure based on SEDC. Fourteen SEDC specimens are designed and tested under monotonic and cyclic loading tests to investigate the semi-rigid workability of SEDC and to evaluate the influence of design parameters of the bending and friction parts. Two working processes, which are the static friction process and the sliding friction process, are clearly reflected by the monotonic test results. The cyclic test results indicate that the SEDC specimens demonstrate satisfactory plastic development with full hysteretic curves, stable load capacity, reliable deformation ability, and favorable energy dissipation ability. The U-shaped bending plates exhibited a track-like deformation pattern without any observed tears or cracks. The NAO friction pads demonstrated a fragmented damage pattern, while the Brass friction pads demonstrated a linear scratch damage pattern. SEDC specimens equipped with Brass friction pads exhibited better low-cycle fatigue performance, which can be attributed to the favorable wear resistance of the Brass material. In addition, finite models of SEDCs are established and validated based on Abaqus. The combined working mechanism of SEDC, including the contribution ratio of load capacity and dissipated energy from the bending part and the friction part, is clearly revealed. Furthermore, the influence of parameters including the thickness (t), width (B), straight section length (l), radius (R), and height (h) of the bending part, as well as the pre-tightening force (pc) and the friction coefficient (f) of the friction part, are also summarized based on both the experimental and numerical analyses. Further discussions, including the calculation of the seismic behavior factor and the measurements for accurate construction, are conducted.

Study on energy dissipation performance of low-yield-point steel shear panel dampers

To investigate the energy dissipation performance of low-yield-point steel shear panel dampers (LSSPD), the eleven full-scale LSSPD specimens were designed and tested. By conducting quasi-static cyclic tests and numerical simulations, the influence of shear plate aspect ratios, flange plate thickness, numbers and layout of stiffeners on the failure modes for energy dissipation performance of LSSPD have been investigated. The results indicate that: The energy-dissipating capacity of the damper is positively correlated with the shear plate's cross-sectional area. Increasing the flange plate thickness can improve the bearing capacity and energy dissipation of LSSPD, but with a limit. The stiffeners can enhance the ultimate bearing capacity of the damper. A single stiffener in both horizontal and vertical directions effectively controls the out-of-plane buckling deformation of the shear plate. It achieves a damper with a full hysteretic curve and a high energy dissipation capacity. However, the arrangement of stiffeners on different sides will decrease the ultimate bearing capacity of the damper. Through finite element supplementary analysis, it is recommended to select the shear plate aspect ratio between 20 and 41, and the flange restraint coefficient βf should not be <10 for damper design. Meanwhile, limiting the stiffener restraint coefficient βs within 45 is recommended to achieve better energy dissipation performance for low-yield-point dampers.

Revisiting the hydrolysis of ampicillin catalyzed by Temoneira-1 β-lactamase, and the effect of Ni(II), Cd(II) and Hg(II).

β-Lactamases grant resistance to bacteria against β-lactam antibiotics. The active center of TEM-1 β-lactamase accommodates a Ser-Xaa-Xaa-Lys motif. TEM-1 β-lactamase is not a metalloenzyme but it possesses several putative metal ion binding sites. The sites composed of His residue pairs chelate borderline transition metal ions such as Ni(II). In addition, there are many sulfur-containing donor groups that can coordinate soft metal ions such as Hg(II). Cd(II) may bind to both types of the above listed donor groups. No significant change was observed in the circular dichroism spectra of TEM-1 β-lactamase on increasing the metal ion content of the samples, with the exception of Hg(II) inducing a small change in the secondary structure of the protein. A weak nonspecific binding of Hg(II) was proven by mass spectrometry and 119m Hg perturbed angular correlation spectroscopy. The hydrolytic process of ampicillin catalyzed by TEM-1 β-lactamase was described by the kinetic analysis of the set of full catalytic progress curves, where the slow, yet observable conversion of the primary reaction product into a second one, identified as ampilloic acid by mass spectrometry, needed also to be considered in the applied model. Ni(II) and Cd(II) slightly promoted the catalytic activity of the enzyme while Hg(II) exerted a noticeable inhibitory effect. Hg(II) and Ni(II), applied at 10 μM concentration, inhibited the growth of E. coli BL21(DE3) in M9 minimal medium in the absence of ampicillin, but addition of the antibiotic could neutralize this toxic effect by complexing the metal ions.

Experimental evidence of nonreciprocal propagation in space-time modulated piezoelectric phononic crystals

A nonreciprocal system composed of a one-dimensional piezoelectric phononic crystal whose periodic electrical conditions are modulated in time is presented. One-way longitudinal wave propagation is studied experimentally and compared to finite element temporal simulations. The modulation is performed by prescribing grounded or floating potential conditions on a periodic set of electrodes through external circuits. This approach makes it possible to consider a wide range of modulation speeds, and the large number of unit cells of the phononic crystal allows us to characterize experimentally the full dispersion curves of the system. This permits to observe the presence of directional bandgaps and to follow the shift in frequencies of these bandgaps as a function of the modulation speed. The experiments show the linear evolution of the central position of the bandgaps with the increase in the modulation speed, as well as their progressive closure, over a wide range of frequencies. Experiments are also used to estimate the evolution of bandgaps in a dispersive system, a problem discussed in several theoretical works but never observed experimentally. This work may constitute the foundation for experimental analysis of Floquet acoustic metamaterials, accelerated-modulation space-time metamaterials, or acoustic analog of the event horizon.

Predicting fracture behavior of quasi-Brittle materials using quantitatively varied geometric specimens: A design method

Fracture toughness (KIC) and tensile strength (ft) are two important parameters for describing the fracture performance of quasi-brittle materials. The accurate determination of both parameters is crucial for the safety design and stability evaluation of real engineering structures. A model and method are developed in this paper for simultaneously determining the KIC and ft for quasi-brittle materials without size effects. And using the geometric structural parameter ae as a key design parameter. This method can get KIC and ft to be obtained by fitting curves to any two sets of quantitative specimens with different geometric structures with ae ratio equal to 3. Additionally, fracture full curves and peak load prediction lines with 95% reliability are established for different fracture modes using quantitative design specimens with an ae ratio of 3. These curves and lines can accurately predict fracture behavior and peak loads of large specimens or engineering structures. The proposed design method is verified by combining experimental studies conducted by other scholars on quasi-brittle materials and the simulation results of ABAQUS software. This paper achieves the objective of accurately predicting the fracture properties of quasi-brittle material structures in the field, using quantitative laboratory specimens of various geometries.