Results Of Static Tests Research Articles

Analysis of Static Plate Load Test Results According to Czech, French, and German Methodologies

Many countries have a specific way of performing and evaluating the static plate load test for assessing the railway substructure deformation resistance, so its values cannot be easily compared for different countries. This paper describes an experimental study that compares the evaluated results of performed static plate load tests according to Czech, French, and German methodologies. To obtain comparable results, several measurement campaigns were carried out on test layers of crushed aggregates in experimental conditions and on a subgrade surface of soil stabilized by hydraulic binders or on sub-ballast layers of crushed aggregates on real railway track structures. The results were further statistically evaluated by arranging them in graphs, and the mutual correlations between individual methods were found. The dependence of the results turned out to be polynomial. For the comparison regarding the tested subsoil material, the correlation appeared to be better for aggregates than for stabilized soils. The performed experimental study aimed to compare the results of the static plate load test according to the mentioned methodologies and to establish mutual correlations between them. Its results can be used for adapting the requirements for the deformation resistance of the railway substructure defined in foreign standards to the Czech environment.

The Effect of Water Cooling on the Mechanical Properties of FSW Butt Joints Made of Aluminium Alloy AA7075-T651

The article presents test results concerning the mechanical properties of friction stir welded joints (FSW) and underwater friction stir welded joints (UWFSW) made of aluminium alloy AA7075-T651. The analysis of microhardness distribution revealed two positive effects of water cooling, i.e. the reduction of the heat affected zone (HAZ) and an increase in the microhardness of the low hardness zone by approximately 15 HV0.1. Static tensile test results revealed that water cooling led to an increase in the yield point of the FSW joint by approximately 18 % (58 MPa) and tensile strength by approximately 9 % (43 MPa). Under low-cycle fatigue conditions, the UWFSW joints were characterised by higher stress amplitude, lower plastic strain amplitude and a lower number of cycles preceding the failure (of the UWFSW joints) than that preceding the failure of the “classical” FSW joints.

Processing and Testing Subscale Motors with Central Finocyl Grain Using Wax Mandrel

In solid propellant rocket motors, the design of grain port geometry primarily dictates the motor ballistic performance. The flexibility offered by the spatial variation of the port shape on motor performance is often discounted due to the requirement of complex mandrel shapes along with their associated manufacturing issues coupled with propellant processing constraints. Literature data indicate improvement in motor volumetric loading and stability by planned distribution of burn surface area along motor length. This paper deals with the realization and testing of a subscale motor with central finocyl-based grain geometry. A novel method of casting complex grain shapes in solid rocket motors using the wax mandrel technique is discussed. The wax mandrel preparation, propellant casting procedure, and wax mandrel removal setup are elaborated. Static testing results of the subscale motor with central finocyl port geometry are also presented as proof-of-concept. This work has demonstrated the feasibility of realizing solid rocket motor grains using the wax mandrel technique, which further enables realization of complex grain designs necessary to meet various mission requirements.

Simulation the interaction of a pile with the soil using a nonlinear mathematical model with a modified Mohr–Coulomb strength criterion

Summary. Static pile tests allow determining the bearing capacity of a pile as accurately as possible. They should be carried out in advance, before the foundation structures are installed, because their results are used to decide on the need for adjustments. However, static tests usually require significant time, which is due to their execution technology. The main disadvantage of static tests of a full-scale pile is the cost. They are the most expensive method, but at the same time they allow the most accurate reproduction of the pile operating conditions, namely, the load on the pile from the superfoundation structures of the building or structure. The calculated value obtained from engineering calculations allows only a preliminary and approximate assessment of the bearing capacity of the pile on the soil. This method is the simplest, but at the same time the least accurate. Numerical simulation allows us to approximate the results of static testing of an experimental pile to the results of modeling, provided that the parameters of the soil environment for the selected mathematical model are identified. In this work, the Midas GTS NX software package was used for numerical modeling of the experiment (computer simulation of testing a full-scale pile with a static compression load). In this case, volumetric finite elements were used to model the soil mass and the pile shaft. To describe the regularities of soil behavior under load, a nonlinear law of deformation of the soil environment with a modified Mohr-Coulomb strength criterion was used. This model combines nonlinear elastic and elastic-plastic models. The paper investigates the nature of the formation of the stress-strain state of the soil mass under the bottom of the pile and along the lateral surface of the pile at all stages of loading during computer simulation of a full-scale pile test. The phases of pile operation mainly along the lateral surface and the inclusion of the bearing capacity component under the bottom of the pile are identified. The formation of vertical stress concentrator zones in the soil mass under the bottom of the pile is recorded. The nature of the load transfer to the soil through the lateral surface of the pile is established according to the distribution of longitudinal forces in the pile shaft.

Management of Acid Rock Drainage Based on Geochemical Characterisation of Waste Rock Material, Study Case: Gold Mining With High Sulfidation Ephithermal (HS) Deposits

Acid rock drainage (ARD) or Acid mine drainage (AMD) is significant challenge for the global gold mining industry, necessitating specialized treatment to prevent its occurrence. Rambajoring is deposits located at the North Sumatra Martabe gold mine, the mine is an epithermal deposit of a high sulfidation system. A crucial step in management of AMD is identifying rocks that potentially produced acid water or not if contact with water and oxygen. Static testing provides an indication of the potential acidity that can be generated by rock samples based on their composition. These rocks are classified into Potentially Acid Forming (PAF) or Non-Acid Forming (NAF). Laboratory analyses including Acid Base Accounting (ABA), Net Acid Generating (NAG) Test, and paste pH, identified all lithology with uncertain category. This uncertainty occurs impact of presence of significant non-pyritic or non-acid forming sulfide sulphur mineral in this case of Alunite (KAl3SO2OH6) minerals. Containing these minerals will result in erroneously high estimations of total sulphur (S) and increasing the calculated of NAPP. Long term implication non-pyritic sulfide may oxidize slowly, leading to delayed acid generation not reflected in static NAPP calculation. Supplementary test to validation static test result and analysis geochemical behaviour of rocks using kinetic testing with Field Column Leach Test (FCLT) method. FDCLT test confirm in eight months period monitoring, all lithology have a lag time before significant acidity is produced and classified as PAF rocks. The leaching properties of material had highest concentrations of iron (Fe), cooper (Cu) and zinc (Zn). Keyword : AMD, ABA, Geochemical Characteristics, NAF, PAF, Kinetic Test, Static Test

Epoxy resin‐based biomass composites based on modified corn stalks: Preparation, properties, and toughening mechanism

AbstractIn this study, a series of sustainable eco‐friendly epoxy resin (EP)‐based biomass composites (DSA‐CS/EP) were prepared using bisphenol A EP as matrix, 2‐methylimidazole as curing agent, and corn stalk (CS) esterified with dodecene succinic anhydride (DSA) as filler. The static contact angle test results showed that the hydrophobicity of CS after esterification with DSA (DSA‐CS) was enhanced, which results in the compatibility of DSA‐CS with EP matrix was improved. And then, the DSA‐CSs were dispersed homogeneously in the matrix without agglomerating. The morphology and properties of the biomass composites were studied and analyzed in order to elucidate the toughening mechanism of CS and DSA‐CS. When the content of DSA‐CS is 15 wt%, the tensile strength and impact strength of DSA‐CS/EP reached a maximum value of 30.39 MPa and 3.34 KJ/m2, which were increased by 128.49% and 81.52% compared with pure EP. Finally, it is deduced that the possible toughening mechanism is that DSA‐CS can not only share part of the external stress but also a mutual solute region is formed between DSA‐CS and EP matrix.Highlights Corn stalks esterified by DSA were used as reinforcement filler for epoxy resin. The cellulose in CS was mainly esterified. The tensile and impact strength of DSA‐CS 15/EP reached a maximum value. A mutual solute region is formed between filler and matrix.

Behaviour of post-tensioned benches made of high-content recycled aggregate concrete reinforced with racquet string fibres

This study investigates the serviceability and structural behaviour of a new type of recycled aggregate concrete (RAC) bench with waste badminton racquet fibres. Twenty-one cantilever benches were tested in two Series with different fibre volume fractions (Vf = 0%, 0.5%, 1.0% or 1.5%). The RAC had 100% of natural aggregates replaced with recycled concrete aggregate (RCA). The benches in Series II were post-tensioned in flexure using an innovative Post-Tensioned Metal Strapping (PTMS) technique using 1, 2 or 3 straps. Tests were carried out to evaluate 1) static loading behaviour, 2) long-term behaviour after 365 days of sustained loading, and 3) human-induced vibrations. The static test results show that benches with 100% RAC and PTMS had higher capacity (by about 25%) that counterpart benches without PTMS. Hence, the maximum flexural strength of the cantilever bench was improved by 5.7% for the cantilever bench with PTMS strengthening, which further enhanced the flexural behaviour compared to the bench with only 1.5% of fibres. The human-induced vibration test results confirmed that the maximum vibration of the benches met the code limits for floor buildings. Finite element analyses of the RAC benches with PTMS were carried out in Abaqus®, and the experimental deflections agreed well (errors <5%) with the FEM results. A simplified fatigue life analysis confirmed that the RAC benches with PTMS can have a potential service life of up to 20 years. The use of glow-in-the-dark (GID) features into the benches in Series II enhanced their night-time visibility and visual appeal by up to 8 h. This research contributes towards the development of new applications for RAC with waste badminton racquet fibres, which can offer more sustainable solutions for the construction of urban furniture.

Synergistic effects of mediated by different 1,2-epoxybutane addition numbers butoxylated alkyl block alcohol ethers and SDS in mixed systems

In this study, nonionic surfactant butoxylated alkyl block ether (AE9Bn) and anionic surfactant sodium dodecyl sulphate (SDS) with different BO additions were mixed at different molar ratios to make a hybrid system. The interaction parameters and aggregation behaviors of the blended systems were investigated by observing the average direct particle drop distribution and microscopic aggregates in combination with the results of static surface tension tests of the blended systems. The diffusion process of the mixed systems was investigated using dynamic surface tension tests. The dynamic contact angle and foam properties of the solutions of the mixed systems were also studied. Finally, based on the experimental results, it was concluded that the mixed system of AE9Bn (n=2,5) and SDS formed a synergistic effect that significantly led to a decrease in CMC, with an increase in the number of BO additions leading to a more significant decrease in CMC. The mixed system is a non-ideal mixed system, which is consistent with the kinetic mechanism of mixing and diffusion. The hybrid system has good aggregation pattern and wetting diffusion behavior and has low foam stability due to slow maturation of Ostwald.

Research on Load Correlation of Blunt Headed Aircraft

Abstract In order to study the influencing factors of static and dynamic loads on short blunt body balanced wing structures in the external atmospheric environment, and to avoid and prevent structural overload and damage, this paper conducted load tests on short blunt body structures and conducted load correlation analysis. This article establishes a dynamic load testing method for internal excitation and measurement, which is more suitable for dynamic load measurement of small structures compared to traditional wind tunnel testing techniques. On this basis, the influencing factors of dynamic loads were studied. By measuring and changing the Mach number, angle of attack, model frequency, and aerodynamic damping data of the model flight, the influence of the above variables on the static and dynamic loads of the model was obtained. The experimental results indicate that the established measurement technique can accurately and effectively obtain static and dynamic test results of the structure. Pneumatic damping is negatively correlated with dynamic loads, with a correlation coefficient of around -0.8. The Mach number and angle of attack are positively correlated with dynamic loads, with a correlation coefficient of around 0.98. This article establishes a new wind tunnel testing and measurement method, analyzes the influencing factors of dynamic loads, and is of great significance for dynamic load measurement and the design of new aircraft.

Shear behavior at the interface of rough surfaces and cohesive soils under axial loading

Foundation elements with rough (textured) surfaces mobilize larger interface shear resistance than ones with conventional smooth or random rough surfaces when sheared against soils under monotonic loading. The overall performance of foundation elements such as piles supporting offshore wind turbines, suction caissons supporting tidal energy converters, soil nails, and soil anchors installed in cohesive soils could be enhanced through utilizing rough (textured) surfaces to resist applied static and/or cyclic loading. This paper describes the shear behavior of smooth and rough (textured) surfaces in kaolinite clay and kaolinite clay-sand mixture soils under static and cyclic axial loading. The experimental investigation presented herein consists of a series of interface shear tests performed on 3D printed rough (textured) surfaces and a 3D printed smooth reference surface utilizing the Cyclic Interface Shear Test system. The paper includes a description of the interface testing system components, cohesive soil specimens’ preparation procedure, smooth and rough (textured) surfaces details, testing procedure, and results of static and cyclic tests. Test results indicate that kaolinite clay-sand mixture soil mobilized larger static and post-cyclic interface shear resistance and volume contraction relative to kaolinite clay soil when sheared against the smooth reference surface. When tested against rough (textured) surfaces with variable asperity height, larger shear resistance was mobilized and larger soil dilation greater than that mobilized by the reference untextured surface in both soils. The results also indicate rough (textured) surfaces exhibited a prevalent frictional anisotropy increases with asperity angle and height in cohesive soils, the surfaces mobilized larger shear resistance and volume change in one direction (i.e., against the asperity right-angled side) than the other direction (i.e., along the asperity inclined side).

Effects of electron beam and atomic oxygen irradiation on hypervelocity - Impact tested / polyimide coated carbon fiber-reinforced plates

In a low-Earth orbit, space debris orbit at approximately the first cosmic velocity. When space debris strike a spacecraft, ejecta (fragments) from the spacecraft are widely scattered. The reduction in the number of ejecta (fragments caused by impact) must also be considered when selecting spacecraft materials. The authors’ group has previously examined the size of ejecta (fragments) and reduction in the number of ejecta. In general, the mechanical properties of polymer materials and CFRP plates may be damaged by space environments, such as radiation (gamma rays and electron beams (EBs)), atomic oxygen (AO), ultraviolet rays, temperature, and thermal cycling. The authors suggested an anti-AO coating/polyimide CFRP as a material resistant to space environments. The effects of EB and AO irradiation on the fracture behavior and ejecta of anti-AO coating/polyimide CFRP were examined for hypervelocity impacts. The results of static three-point flexural tests were compared with the fracture behavior and ejecta. A two-stage light-gas gun was used for the impact tests. Spherical projectiles formed of aluminum alloy 2017-T4 with a diameter of 1.6 mm were used. Photographs of the ejecta scattered in front of each polyimide CFRP plate were captured from the side using a high-speed video camera. The number and weight of the ejecta on the front side and perforation holes were examined.

Study on construction technology and bearing mechanism of pressure cast-in-situ pile with spray-expanded frustum

The pressure cast-in-situ pile with spray-expanded frustum (PCPSF) is a new type of pile developed by the last author, which is composed of pile body, ribbed plate and expanded body with double-frustum. This paper presents the equipment used to produce the PCPSF and the spray-expansion extrusion vibration and pressure method used for construction of the PCPSF. The PCPSF model of cement soil transition layer around pile is built with finite element software. The accuracy of the numerical calculations is verified through a comparison with the results of static load tests conducted on PCPSF. Furthermore, the impact of the expanding ratio, expanded body location, and ribbed plate length on the response of the PCPSF is investigated. The results show that: (1) the ultimate bearing capacity (UBC) of PCPSF single pile is proportional to the diameter expanding ratio and the length of the ribbed plate; (2) the improvement of the bearing capacity of single cubic concrete of PCPSF decreases with the increase of expanding ratio; (3) the bearing capacity of expanded body can be activated ahead of time as it advances up in position, and there is a trend toward a steady increase in the combined bearing capacity of the expanded body and pile end; (4) as the expanded body moves up, the vertical stress of the soil below pile tip decreases, the rate of decay of additional stress is accelerated; (5) under the identical circumstances, the PCPSF's bearing capacity is 1.5 times greater than the traditional cast-in-place pile's, and the presence of cement soil transition layer contributes 15 % of the lateral resistance of the PCPSF.

Salt-freeze resistance and life prediction of geopolymer recycled concrete mixed with rice husk ash and modified rubber particles

Rice husk ash (RHA) and Span-40 modified waste rubber particles (WRP) were mixed into geopolymer recycled concrete (GRC) to improve its frost resistance in normal and chlorine environment. The freeze-thaw and static loading test results show that GRC has the best freeze-resistance when 5 %RHA and 10 %WRP are added. The strength loss rate of GRC after 200 freeze-thaw cycles in normal environment and chlorine salt environment is 8.3 % and 8.8 % lower than that of GRC without RHA and modified WRP, respectively. Based on the test results, the material damage model and strength loss model of GRC doped with RHA and modified WRP were established. The failure probability and service life of GRC were predicted. The results showed that the failure probability of GRC mixed with 5 %RHA and 10 %WRP was reduced by more than 10 % compared with that of GRC mixed with no RHA and modified WRP at 200 freeze-thaw cycles under normal environment and chlorine salt environment, and the failure probability decreased with the increase of cycle times. The life prediction results showed that the service life of GRC mixed with 5 %RHA and 10 %WRP increased by 17.9 % and 21.6 %, respectively, compared with that of GRC mixed with no RHA and modified WRP under the freeze-thaw cycle of normal environment and chlorine salt environment.

FLEXURAL STRENGTHENING OF THERMALLY MODIFIED RUBBERWOOD GLULAM BEAMS WITH FRP UNDER STATIC AND CYCLIC LOADS

The purpose of this research is to investigate the flexural properties and cyclic response of strengthened with fiber reinforced polymer (FRP) of glulam beam made from thermally modified rubberwood. The efficiency of three different FRP was assessed based on the bonding properties. The experimental results demonstrated that the glass fiber-reinforced polymer (GFRP) showed the strongest adhesion. Static and cyclic flexural tests were also carried out to study the behavior of glulam beams. The static test results indicated that double sides strengthened glulam beam enhanced their flexural strength. The strengthened glulam beams under static load demonstrated a reduced deformation rate due to increased modulus of rupture compared to non-strengthening glulam beam. The cyclic load test showed the strengthening effect on improving energy dissipation and ductility, while the impairment of strength did not affect.

Research on the Vibration Fatigue Characteristics of Ancient Building Wood Materials

In this study, we selected ancient building timber as the research object. A series of static load tests were conducted to analyze the different performances of timber under tensile and compressive loads. After that, vibration fatigue tests on ancient timber samples were carried out under different upper limit stress ratios. Finally, a dynamic constitutive model of ancient timber was established based on the Ramberg–Osgood model. The static load test results show that the tensile strength was approximately 80% of the compressive strength. Meanwhile, the samples that failed under compressive pressure had obvious residual strength, and their failure strains were also much larger than those under tensile stress. In the vibration fatigue tests, the stress–strain curves were analyzed and the results showed that the curves displayed a trend moving to sparse from dense during the loading process. Meanwhile, the curves moved right with the increase in the upper limit stress ratios. The relationship between axial strain and the number of cycles appeared to be characterized by a three-stage form, i.e., damage occurrence, damage expansion, and damage penetration, and this relationship was formulated by a nonlinear function model. Finally, a dynamic constitutive model with high accuracy in describing the vibration fatigue characteristics of ancient timber was established by converting constant parameters to the variable parameters of the Ramberg–Osgood model.

Graph-Analytical Method for Calculating Settlement of a Single Pile Taking into Account Soil Slippage

Most of the existing methods of pile settlement calculation, including normative methods, do not fully take into account the processes occurring in the soil when loads are transferred to them and the changes in the properties of the contact zone soils. This leads to underutilisation of the bearing capacity of the soil, and the calculated settlement value may differ several times from the real values. In this paper, a graph-analytical solution to the problem of interaction of a single pile with a three-layer soil foundation is proposed to determine the settlement, taking into account the complex nature of the pile operation and the processes occurring in the soil when loads are transferred to them. The proposed method allows to use the non-linear behaviour of the soil on the lateral surface and under the tip of the pile, the possibility of its detachment and slippage after reaching the ultimate strength of the soil, changes in the properties of the contact zone soils, and the load distribution on the pile between its lateral surface and the tip. To verify the proposed graph-analytical solution, a comparative analysis was performed with the numerical method in the Plaxis 2d software (version 21.00.01.7) and with the results of static tests of piles at the construction site. To determine the strength reduction factor at the contact of soils with concrete, laboratory tests were carried out on a direct shear apparatus. Based on the results of the performed calculations, graphs of the dependence of settlements on loads were plotted, conclusions were drawn about the possibility of using the graph-analytical method, and prospects for further development and improvement of the graph-analytical method were proposed.

Installation of a Pit Fence in Cramped Conditions

The construction of buildings and structures in cramped conditions requires a special approach from hydraulic engineers and builders, requiring the preservation of the surrounding development in a working condition. This circumstance requires a geotechnical forecast of deformations of objects falling into the zone of geotechnical influence of the construction of a building under construction at the design stage and then the organization and implementation of geotechnical monitoring of deformations as a result of construction and installation work. It should be noted that the objects of the surrounding development can be in different categories of technical condition. According this circumstance the permissible deformations may be different. In any geotechnical case, there is an urgent need to install excavation fences that perform a dual task: both ensuring the stability of the soil walls, and reducing the impact of the new construction object on existing buildings. The determination of the bearing capacity of the enclosing structures of the excavation, especially the retaining soil anchors themselves, is of great importance in modern geotechnical construction. The engineering method used in this article to determine the bearing capacity of drilling-injection anchors with sufficient accuracy for technical calculations showed the convergence of calculated and real values based on the results of static tests.

A comparative study of self pierceing riveting and mechanical clinch of DP590-Al5754 high-strength steel and aluminum alloys

This paper presents a comparative study of two joining processes, self piercing riveting (SPR) and mechanical clinch, used to join DP590 high-strength steel and Al5754 aluminum alloy. A comparative study of microhardness, tensile shear properties, fatigue properties, and economics of joints from both processes was conducted. The findings indicate that the highest hardness levels are observed in the rivet leg region for SPR joints and in the neck region for mechanical clinch joints. The maximum failure load and energy absorption values of SPR joints were found to be 1.46 and 9.07 times higher, respectively, than those of mechanical clinch joints. The static tensile test results demonstrate that the strength and hardness of SPR joints in aluminum sheets subjected to cold work hardening are significantly lower than those of steel sheets. Therefore, the failure of SPR joints is primarily attributed to the deformation and fracture of the lower aluminum sheet. Mechanical clinch joints fail by neck fracture because the steel sheet neck becomes brittle by cold work hardening and the neck thickness is small. The fatigue behavior of SPR joints was observed to be superior to that of mechanical clinch joints. The findings of the scanning electron microscopy and energy spectrum analysis suggest that fretting wear between the upper and lower sheets results in fatigue fracture of the lower sheet in the joints. When joining the same material on a large scale, the selection of mechanical clinch over SPR can prove an effective method of reducing costs. Furthermore, the selection of a set of dies with an extended life can contribute to the reduction of joining costs.

Influence of gate cutoff effect on flow mode conversion and energy dissipation during power-off of prototype tubular pump system

Understanding the cutoff effect of gates is essential for enhancing the overall quality of the pump system's power-off process, minimizing energy losses, and reducing potential risks associated with hydraulic transients. In this study, both numerical simulations and experimental investigations were conducted on the power-off process of a tubular pump system, considering scenarios with and without gate functionality. The simulations utilized a dynamic mesh method to model gate movement, incorporated the torque balance equation to determine the real-time impeller speed, and applied the 3D-VOF method for free surface modeling in reservoirs. Power-off experiments were performed on a model pump system and a prototype pump system to validate the numerical simulation results. To elucidate the mechanism of the gate's cutoff effect, flow modes during the power-off process were categorized based on the four-quadrant static test results of the pump, revealing the deviations between transient and static characteristics. By comparing the transient flow structures of the pump system under different gate operating states, specific energy dissipation behaviors during gate cutoff were analyzed. The research findings enhance the understanding of hydraulic transients, which is essential for developing more sustainable and resilient energy systems.

Parameter determination of Johnson–Holmquist–Cook constitutive model and calibration for Indiana Limestone

In this study, a comprehensive parameter determination procedure for the Johnson–Holmquist–Cook (JHC) constitutive model is introduced, including calibration and validation processes for Indiana Limestone rocks. The procedure is conducted utilizing the existing physical and mechanical properties of Indiana Limestone. To obtain an accurate set of parameters for the JHC model for Indiana Limestone, an extensive dataset comprising mechanical and physical properties of Indiana Limestone rocks was initially compiled. The static mechanical tests incorporated uniaxial compression, triaxial compression, direct tensile, and uniaxial strain data, while the dynamic mechanical test data was primarily derived from the Split Hopkinson Pressure Bar experiments. Subsequently, the JHC constitutive model parameters were determined using existing literature data, employing statistical analysis, theoretical derivation, and numerical back analysis techniques. One of the damage parameters was determined through numerical post-peak behavior calibration of triaxial compression strength test results on experimental data. Finally, the accuracy of the determined parameters was validated by comparing the numerical and experimental results of both static and dynamic tests. This study effectively addresses the challenges associated with the numerical method using the JHC material model, such as the complex parameter determination process and the costly required tests, thereby preserving the efficiency and applicability of the numerical method.