Theory Research Articles

Mathematical model and experimental verification of self-centering energy dissipative brace equipped with disc spring and wedge block

The novel self-centering energy dissipation brace composed of disc spring group and wedge block group (DW-SCB) is introduced. The working mechanism of the DW-SCB and the force mechanism of each component are described. The stress analysis of the disc spring group (DSG) and the wedge block group (WBG) were carried out, and the DW-SCB theoretical prediction model was established. Three specimens with different disc spring preload lengths were fabricated, tested, and discussed. Furthermore, the established theoretical model was verified, and the theoretical model correction method considering the processing and assembly errors of the DSG was proposed. The tested data show that the hysteresis curve of DW-SCB is a typical flag shape, and there is almost no residual displacement after multiple loading. An increase in the preload length of the disc spring increases the yield load and bearing capacity of the DW-SCB but has no change on the stiffness of DW-SCB. All the components of the three specimens were not damaged after multiple loadings, which show that the DW-SCB has stable multiple seismic performance and recoverability. Significant, although the machining error of the disc spring leads to a large error between the experimental and theoretical curve of the DSG, the error correction method of the DSG proposed in this study can improve the prediction accuracy of the theoretical model, making the DW-SCB theoretical prediction model more accurate and reliable. The theoretical model considering the error of DSG can better predict the stiffness and load of DW-SCB, which can provide a reference for engineering design and application.

An experimental and analytical investigation to determine thermal conductivity of epoxy-filler composites for space applications

Thermal conductivity of epoxy-filler composite based Thermal Interface Materials (TIMs) is of utmost importance for thermal management systems used in space applications. Previous studies have shown that depending on the filler particle mixed into the epoxy, thermal conductivity of the composite can either be increased or decreased. Towards that, we have selected four different filler particles (micron sized) – aluminium, copper, zinc and silver to enhance the thermal conductivity of the base epoxy. Thermal conductivity of these 4 epoxy-filler composites has been determined experimentally using an indigenous developed setup at the temperatures ranging from 4.2 K to 323 K. The values have also been reported at various volume fractions (up to 15 %). In addition, after each preparation as the filler particles are mixed mechanically into the epoxy, they are randomly distributed, and this can affect the composite’s thermal conductivity (for the same volume fraction). The experimental determination of thermal conductivity for all the possible distributions is a time consuming, and cumbersome task. In the literature, thermal conductivity values are usually reported for few possible distributions. Therefore, we have developed a novel analytical model to predict all the possible values of thermal conductivity for a specific volume fraction. The predicted values compare well with our experimental data reported in this work at temperatures ranging between 338 K (above room temperature) to 4.2 K (liquid helium temperature). The predicted values are also in good agreement with the experimental values of different fillers such as red mud, pine wood dust and glass fiber etc. from the literature. Additionally, in comparison to other theoretical models like Lewis-Nielsen, Rule of mixture, and Poisson’s distribution, the present model predicts the thermal conductivity values more precisely. This work will be significant in the designing of components where heat transfer plays an important role towards the safety of the component.

Effect of temperature and frequency on the dielectric behaviour of cellulose nanocrystals

Nanocellulose is a promising material for advanced applications due to its renewable nature, non-toxicity, eco-friendliness, mechanical strength and other unique properties. This study investigates the dielectric properties of cellulose nanocrystals (CNCs) derived from wastepaper through acid hydrolysis, across a temperature range of 30°C to 100°C and a frequency range of 1 Hz to 10 MHz. Using theoretical models such as the modified Cole-Cole model, Jonscher's universal dielectric response (UDR) model and modified Kohlrausch-Williams-Watts (KWW) model, a detailed analysis is performed. The results indicate that the dielectric properties depend on temperature, with the frequency dispersion of the real (ε′) and imaginary parts (ε″) of the dielectric permittivity fitting the modified Cole-Cole equation. These values show an initial increase up to 70°C (ε′∼ 6000 and dielectric loss <1) followed by a decrease at higher temperatures, which is linked to the hydroxyl groups. A temperature dependence is also observed in space charge conductivity, free charge conductivity and relaxation time. Non-Debye type behaviour is attributed to asymmetrical features in the electric modulus spectra, as explained by the modified KWW model at various temperatures. The frequency variation of AC conductivity adheres to Jonscher’s power law and the temperature variation of the frequency exponent (0≤ s ≤1) indicates a correlated barrier hopping conduction mechanism for charge carriers. Overall, these findings highlight CNCs as excellent candidate for antistatic applications, demonstrating conductivity ranging from 10−5 to10−9 Scm−1. The results also suggest CNCs can be used in energy storage applications due to their outstanding dielectric properties and low dielectric loss (<1).

The generation mechanism of cutting heat and the theoretical prediction model for temperature on the rake face of the cutting tool in Zirconia ceramics

Cutting temperature and its distribution are crucial factors influencing tool strength and wear rate, due to the hardness and brittleness of Zirconia (ZrO2) ceramics, significant challenges arise in both direct temperature measurement in the cutting zone and theoretical analysis of cutting heat. Thus, focusing on the turning characteristics of ZrO2 ceramics, this study analyzes the mechanism of cutting heat generation and proposes utilizing thermodynamic state equations to determine the cutting heat source on rake face of tool. Based on the heat source method, a theoretically prediction model for temperature distribution on rake face is established. This model considers primary cutting parameters, workpiece material properties, crack fracture characteristics of the machined surface, and thermal characterizations of the tool material. The relationship between tool wear and cutting temperature is experimentally analyzed to determine the characteristic temperature that indicates the initial stage of tool wear. The validity of the theoretical model is verified, as the predicted results show high consistency with experimental results within the range of experimental parameters, with a relative error within 15.2 %.The results reveal the highest temperature during brittle cutting occurs within the cutting layer area, with the highest temperature occurring approximately 50 μm from the tool tip, followed by a gradual decrease beyond 150-200 μm. This study also demonstrates that cutting heat in ceramic turning does not solely originate from friction heat between tool flank-workpiece but also includes impact heat from tool rake face-workpiece, which under certain cutting parameters exerts a more significant influence on cutting temperature. This model can facilitate the selection and optimization of cutting process parameters for brittle materials and provide a theoretical basis for analyzing the relationship between tool thermal damage, thermophysical properties, and tool wear.

Evidence-informed approach of sighs in the scope of osteopathic practice

Osteopathic practice attaches great importance to the respiratory function in theoretical models, in the approach to respiratory disorders and in the use of breathing techniques for therapeutic purposes. The study of different parameters of breathing would be a way to deepen the application of breathing to osteopathic practice. In this respect, the sigh is a clinical element of interest.The osteopathic grey literature is rich in examples of the use of sighing in an empirical framework with interpretations during the anamnesis, the diagnostic and the therapeutic phases. Osteopaths' empirical experiences of sighing should be compared with available experimental data to improve the quality of osteopathic care. We are not aware of any study specifically related to sighing in an osteopathic context, but the psycho-physiological data on sighing is growing.This narrative review presents scientific data on the phenomenon of sighing. The physiological and pathophysiological conditions of sighing are presented in the context of the reasons for consultation encountered in osteopathic practice. The sigh as a diagnostic tool for various conditions is discussed. Therapeutic avenues explore how sighing could be an element in controlling the effects of osteopathic treatment, or an active element in the treatment itself. Finally, the place of the sigh as an element of communication within the consultation is described. In these different fields, the contribution of scientific data leads to several contradictions with the osteopathic empirical experience. This review describes avenues of future research needed to clarify the role that sighing might play in osteopathic practice.

Investigation of the performance of oil-free linear compressor with magnetic resonance spring for pulse tube cryocooler

This study proposes a new type of oil-free linear compressor with a magnetic resonance spring, which uses a magnetic resonance spring to provide restoring force and adopts gas-lubricated bearings to provide support force for the piston. The frequency characteristics of the compressor, including magnetic spring stiffness, gas spring stiffness, and resonance frequency, are studied through experiments and theoretical analysis. The magnetic spring stiffness is 31403.31 N/m of the design compressor. Hooke’s law and Fourier decomposition are employed for the gas spring stiffness measuring the compression pressure gauged. Meanwhile, the gas spring stiffness is also obtained from the amplitude-frequency characteristic of the compressor by the back stepping technique with an electric parameter frequency scan. The experimental results demonstrate that the three measurement methods have good consistency in measuring the gas spring stiffness. The equivalent gas spring stiffness measured using the three methods and theoretical model are 72600.92 N/m, 71275.84 N/m, 71967.15 N/m, and 71929.25 N/m at 3 MPa charged pressure measured respectively. In addition, the refrigeration performance of the pulse tube cryocooler driven by the compressor is tested and the lowest temperature obtained in the cold end is 46.3 K under different charge pressure. Furthermore, an optimal frequency exists that enhances the refrigeration performance of the pulse tube cryocooler, and this optimal frequency remains constant regardless of changes in the charge pressure.

The West: An autoimmune disease?

ContextThis work explores the paradoxical stress mechanisms in Western societies, marked by consumption and comfort. Despite the perceived well-being of modern capitalist societies, a profound psychosomatic discontent manifests, reflected in the rise of stress-induced illnesses, autoimmune diseases, and psychiatric disorders. The article uses the metaphor of autoimmunity to describe Western societal dysfunction, drawing parallels between biological self-destruction and societal self-harm driven by hyper-individualism, economic pressures, and digital dependencies. ObjectivesThis study aims to analyze the mechanisms through which Western societies contribute to self-destructive processes, paralleling the way autoimmune diseases function within the body. It seeks to demonstrate how excessive control, consumerism, and the digital environment exacerbate stress, which in turn contributes to both physical and psychological deterioration. The philosophical question underpinning this analysis is whether the societal and economic systems in the West are undermining the self-defense mechanisms of their members, akin to an autoimmune response. MethodThe article adopts a qualitative and theoretical approach, integrating concepts from psychology, psychoneuroimmunology, and epidemiology. The author incorporates clinical observations, epidemiological data, and philosophical reflections to explore the effects of chronic stress on mental and physical health. Drawing on psychoneuroimmunology, the research explores the bi-directional interaction between the mind, nervous system, and immune function, focusing on the relationship between stress, inflammation and autoimmune diseases. ResultsOur exploration reveals a significant correlation between the rise of autoimmune diseases and the psychosocial stresses of Western capitalist societies. Epidemiological data support the link between chronic stress, psychiatric disorders, and autoimmune conditions. The article also highlights how the digital economy's manipulation of stress and fear (such as through FOMO) contributes to widespread psychological distress. This stress, in turn, disrupts immune function, leading to a cycle of physical and psychological degeneration. InterpretationWestern societies, through their relentless pursuit of control, comfort, and consumption, create environments of heightened stress that mirror the dysfunctions of autoimmune diseases, where the body turns against itself. The research suggests that modern capitalist structures are pathogenic, exacerbating stress, weakening immune resilience, and fostering mental health crises. The article concludes that a holistic approach is necessary to address this systemic dysfunction, advocating for a reconceptualization of health that integrates mental, physical, and societal well-being.

Synthesis investigation and exploring of new tetraglycidyl bisurea bisphenyl S polyepoxide as an excellent corrosion inhibitory resin for mild steel in 1M HCl environment: Comprehensive approaches

This work reports the synthesis of new epoxy resin namely tetraglycidyl bisurea bisphenyl S (TGBUBS). TGBUBS was characterized through using nuclear magnetic resonance (1H NMR and 13C NMR) and attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR). TGBUBS was investigated as an excellent organic inhibitor for protecting the mild steel from corrosion in 1M HCl solution at different concentrations. Anticorrosion protection behaviors were evaluated and more discussed including different techniques such as potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and contact angle (CA) measurements. The obtained results showed that the TGBUBS exhibited inhibition efficiencies at lower concentration are 93.19 % (PDP) and 91.21 % (EIS), respectively. Further, PDP measurements indicated that the TGBUBS acted as a mixed-type inhibitor in 1M HCl solution. Furthermore, SEM and EDS analysis showed a significant reduction in the corrosion on the mild steel surface when the inhibitory epoxy resin was present compared to the blank solution (1M HCl). The effectiveness and interactions of the new epoxy resin on the mild steel surface were also predicted using DFT calculations and molecular dynamics (MD) simulations. The theoretical approaches are in agreement with the experiment results.

Acoustic black hole immersed sonoreactor for high-efficiency cavitation treatment

Developing innovative sonoreactors to enhance acoustic processing efficiency holds immense importance in the field of sonochemistry. Traditional immersed sonoreactors (TISs) mainly produce cavitation at the probe tip, with a relatively weak cavitation around the probe, resulting in posing challenges for high-efficiency cavitation treatment. Here we propose an acoustic black hole immersed sonoreactor (ABHIS) in longitudinal-flexural coupled vibration, enabling high-efficiency cavitation treatment by unleashing the cavitation potential of the probe. The symmetrical structure of the probe is altered to introduce a coupling of flexural vibration mode, and an acoustic black hole (ABH) profile is integrated to further enhance both flexural wave number and amplitude. In this paper, we present a systematic theoretical design method for ABHIS and compare its performance with TIS using finite element method (FEM). An ABHIS prototype is fabricated and subjected to experimental tests and cavitation observation. The results demonstrate that our theoretical analysis model accurately predicts the frequency characteristics of ABHIS. The proposed ABHIS exhibits satisfactory dynamic characteristics, with significantly increased vibration displacement and acoustic radiation ability compared to TIS. Importantly, the ABH design significantly expands ultrasonic cavitation regions and enhances acoustic radiation intensity of ABHIS resulting in a substantial improvement in acoustic processing efficiency.

Assessment of joint distributions of wave heights and periods

Short-term joint distributions of wave heights and periods provide information about the sea surface that is needed for engineering applications. In recent years much effort has been invested in predicting and validating the (univariate) distributions of wave heights; however, the same cannot be said about the joint probability of wave heights and periods. Comparisons of the joint distribution models with field observations are quite limited in terms of both the duration of the data and the number of locations considered. In addition, the often-contradicting demands for longer sea-state records and stationarity in the datasets have presented researchers with a bit of a conundrum. It is likely that some previous studies that aggregated data from several non-stationary sea states might have yielded improper inferences. The current study attempts a robust assessment of the available theoretical distribution models utilizing an extensive dataset of wave measurements around the UK coast. The results indicate that the Zhang and Guedes Soares (2106) model generally performs the best, and is perhaps a notable improvement over the somewhat bleak outlook laid out for these types of models in earlier years. The results also suggest that the discrepancy between the models and the data arises primarily from the poor ability of the marginal period distributions to capture reality.

Carbon taxes, CO2 emissions, and the economy: The effects of fuel taxation in the UK

Carbon taxes remain economists’ preferred policy tool to curb emissions, but they are often criticized by the wider public as ineffective and damaging to the economy. This paper provides new evidence of the effectiveness of carbon taxation through empirical ex-post analysis, using the synthetic control method. We base our quantitative work on a theoretical general equilibrium model with dirty and clean transportation. We take the predictions of the model to data on the UK Fuel Tax Escalator, and estimate the impact of the tax on CO2 emissions, GDP, and transport behaviour. With a potential control pool of OECD countries, we estimate the difference between the observed outcome in the UK and a synthetic counterfactual UK. We find that the tax has a large and significant impact on CO2 emissions from traffic, while there is no discernible impact on GDP or growth. We do not find large changes in driving behaviours, but the available evidence points to a possible switch to rail travel from road travel. Our results are relevant for energy policy makers as they show how a suitable pricing system can effectively reduce climate-damaging emissions without causing macroeconomic damage.

Calcium alginate-encapsulated propolis microcapsules: Optimization, characterization, and preservation effects on postharvest sweet cherry

The increasing consumption of fresh fruits and vegetables has led to the development of eco-friendly and active preservation materials which have slow-release effect of antioxidant/antifungal agents. The propolis microcapsules (PM), utilizing calcium alginate as the wall material, incorporating ethanolic extract of propolis (EEP) as the core material, were prepared by ionic gelation method and conducted a investigation of its characteristics After optimization by single factor experiment and theoretical response models, PM which was prepared by dropping 9.3 g L−1 100 mL sodium alginate solution containing 9.8 mL EEP into 0.22 mol L−1 calcium chloride solution showed an encapsulation efficiency of 69.29±1.12 %. Prepared microcapsules were spherical with a dense surface which protected propolis well from the environment, retained a large number of bio-active compounds and improve thermal stability of propolis. Moreover, the microcapsules exhibited good slow-release effect and good inhibitory influence on the development of Alternaria Alternata growth which the colony diameter of the control was 41.38 % higher than the treatment at day six. With 5.0 g PM placed in the small non-woven bag in the application on sweet cherries with non-direct contact method, the decay rate and weight loss of fruits were reduced by 47.5 % and 17.6 %, concurrently the PM also effectively maintain the good appearance, hardness, antioxidant capacity by slowing the reduction in the content of total phenols, flavonoids and enzymatic activities. Therefore, the PM with superior antioxidant and antifungal capacity have the great potential to design as a practical active materials for fruits preservation.

Model study on potential removal of toxic Se(VI) by organically modified montmorillonite

The theoretical DFT-D3 approach was used in the model study of the immobilisation of the toxic selenate oxyanion, with montmorillonite clay modified by poly(2-methyl-2-oxazoline) polymer represented by a pentamer unit, and tetrabutylphosphonium cation. The calculated basal spacing for Se-POx-Mt and Se-TBP-Mt models provided similar results differing by 0.2 Å (18.3 Å for Se-POx-Mt and/or 18.5 Å for Se-TBP-Mt, respectively). The calculated intercalation energy, ΔEint, showed a suitability of both modified Mts for trapping of (SeO4)2– oxyanions favouring the Se-TBP-Mt (–210.7 kJ/mol) system compared to Se-POx-Mt (–124.5 kJ/mol). The main interactions in both models were classified as hydrogen bonds of weak (CH···O) and moderate-to-strong (OH···O) strength. The calculated total and projected vibrational density of states of the Se-POx-Mt and Se‑TBP‑Mt models, obtained from the ab initio molecular dynamics simulations, were used for distinct identification of vibrational modes of the intercalated (SeO4)2– ion in the interlayer space of both models.

Environmental regulation, R&D subsidies, and industrial green total factor productivity

In the face of worsening global environmental degradation, significant attention has been devoted to the greening of industrial transformation and development, specifically by improving industrial green total factor productivity (GTFP). We explored the impact of environmental regulations on industrial GTFP and the moderating influence of R&D subsidies. We established a theoretical model in which environmental regulations affect industrial GTFP, and this relationship is moderated by R&D subsidies. The results revealed that the impact of environmental regulations on industrial GTFP is U-shaped and that the current level of environmental regulation is insufficient to boost industrial GTFP. Green technological innovation plays a mediating role in the effect of environmental regulations on industrial GTFP. Furthermore, R&D subsidies nonlinearly moderate the relationship, resulting in a steeper U-shaped curve and accelerating the arrival of the tipping point. These findings provide theoretical support and a reference for government policies that promote industrial greening.

A 3-DOF spreading precision positional stage for ductile end-face fly-cutting of quartz glass

Ductile removal is widely employed to eliminate subsurface damage in brittle materials. Achieving this requires the cutting depth to be set extremely low, presenting significant challenges for error compensation and precise feeding of the machine tool. In this paper, a novel three-degree-of-freedom spreading precision positioning stage is developed to mitigate the effects of workpiece deflection errors and feed resolution on the depth of cut during the end-face fly-cutting process. First, a bridge and half-bridge composite structure is designed to facilitate the planar spreading of the spatial motion mechanism. A mathematical model of the composite structure is developed based on elastic beam theory. Second, the effects of various structural parameters on the amplification ratio of the structure are investigated. The accuracy of the theoretical model is verified by finite element analysis. Finally, ductile fly-cutting experiments on quartz glass are conducted using a precision 5-axis machine tool.

Topological pumping in an inhomogeneous Aubry-André model

The Aubry-André model is a fundamental theoretical model that exhibits interesting topological features. In this paper, we examine topologically protected boundary states in the inhomogeneous off-diagonal Aubry-André model. In contrast to the homogeneous case, the inhomogeneity triggers boundary states at phase boundaries that separate two distinct non-trivial topological domains. Remarkably, the topological character of the boundary states is predicted through topological pumping, where a boundary state is transferred from one boundary across the bulk region to the other by adiabatically tuning the pump parameter. Moreover, the role of the off-diagonal modulation strength (λ) on the transfer efficiency of the topological pumping is addressed. To support our results, we investigate the time evolution of a continuous-time quantum walk and show that its spread rate and λ are inversely related. Our work provides a new avenue to harness topological features of the Aubry-André model, where topological pumping can be used for robust quantum transport.

Atomic insights into the ductile–brittle competition of cracks under dissolution

Environmental effects can determine the ductile–brittle behavior of cracks at the atomic scale, but the underlying processes remain poorly understood and contentious. Here, we report the competition between ductile and brittle behaviors at crack tips induced by the prevalent environmental effect of dissolution. Our findings reveal that this competition is driven by two fundamental deformation mechanisms related to dissolution: crack blunting and defect accumulation. Through separate evaluations of dissolution-induced cleavage and dissolution-induced plasticity, we demonstrate that these deformation mechanisms not only dominate brittle fracture toughness but also lead to dislocation slip. We have developed a theoretical model to predict the ductile and brittle behavior of cracks under dissolution, and the theory aligns well with the simulation results and remains consistent with existing experimental trends. This work will broaden the microscopic understanding of ductile and brittle fracture of cracks in complex environments.

Chitosan extracted from the feather of Dosidicus gigas crosslinked with glutaraldehyde for use as a 99Mo adsorbent

The production of Technetium-99 m (99mTc) is important for cancer diagnosis. The solvent extraction is the most widely used method to obtain 99mTc; however, due to the evaporation of the polluting solvent into the environment, a radiochemical separation using a chromatographic column system based on adsorbent materials would be cleaner and more efficient.In this study, squid feather (Dosidicus gigas) chitosan (SFC) polymers have been synthesized and crosslinked with glutaraldehyde solutions at concentrations of 50, 40 and 25 % to study the adsorption of 99Mo with the aim of test a promising material to produce 99mTc in the chromatographic column of the 99Mo/99mTc generator. Likewise, the same methodology of synthesis was performed using a commercial chitosan (CC) as a control. Deacetylation degree was measured obtaining 74.15 % and 77.65 % for the SFC and CC polymers, respectively. The molecular weight obtained was 990.72 kDa for SFC and 722.72 kDa for CC and the characterization of the biopolymers was performed with FTIR, SEM, XRD, TGA y FT Raman techniques. Equilibrium time, adsorbent mass and pH effect were evaluated as factors that influence the adsorption process of 99MoO4-2. The zero load point (pHPZC) analysis confirmed the positive charge of the crosslinked polymers, improving the adsorption capacity of 99MoO4-2 at low pH values between 2 and 4, following a pseudo-first order model. With respect to the adsorption isotherms, they exhibit maximum values of 99MoO42- of 482 mg g−1 SFCG40 and 502 mg g−1 CCG25 with a better fit to the Langmuir theoretical model.

+Analytical Approach for Predicting the Moment-Curvature Response of Structural Lightweight Reinforced Concrete Beams

With the switch towards performance-based design procedures, the prediction of the flexural behavior of lightweight reinforced concrete, LWRC, members using advanced and reliable analytical tools has been of great interest to researchers. This paper proposes nonlinear analytical and numerical procedures based on sectional analysis and finite element methods for predicting the moment-curvature and load-deflection responses of structural LWRC beams subjected to pure bending. The proposed analytical and numerical models were validated experimentally by casting and testing a series of eight full-scale LWRC beams under four-points bending configuration. The effects of different compressive strengths of concrete and tensile reinforcement ratios on the flexural behavior of LWRC were examined. The analytical and numerical predictions of the load-deflection behavior and the moment-curvature and load-deflection responses of the LWRC beams investigated, compared very well with the corresponding responses measured from experiments, and test results of previous studies existing in the literature. Among the parameters evaluated using sensitivity analysis, the compressive strength had a significant influence on the flexural strength and stiffness of LWRC beams, whereas the compressive reinforcement ratio was the most important factors affecting the energy absorption and curvature ductility. Moreover, the theoretical models developed could serve as viable tools for simplifying the design process of structural lightweight reinforced concrete members and enhance their applications.

Dynamic response of spring valve subjected to underwater pressure pulse

Spring-loaded valves are widely used to protect sealed containers filled with liquid against sudden excessive overpressure; however, the unstable vibration of a valve spool under dynamic loading may lead to safety incidents. This study aims to investigate the nonlinear vibration processes of a valve spool subjected to an underwater pressure pulse. To achieve this objective, the spring-loaded valve was simplified to an air-back mass spring with a constraint boundary (AMSCB). A modified split Hopkinson pressure bar (SHPB) was adopted to generate a controllable pressure pulse to establish the relationship between the specific impulse and the discharged water mass. Following the experimental verification, the influences of the pressure pulse parameters and dimensionless time on the motion characteristics of the mass block and flow rate were studied based on finite element (FE) simulations. Five motion modes were identified according to the number of collisions with the constraint boundary and changes in movement direction: (i) no collision, (ii) single collision, (iii) chatter, (iv) single collision with direction change, (v) multiple collisions. Moreover, a theoretical model for predicting the movement of a mass block was developed and validated against numerical results. The classification phase diagram of the motion mode is presented in a two-dimensional plane composed of specific strength coefficient ϕ and fluid-structure interaction coefficient ψ, and the influence of the geometrical parameters of the AMSCB on the classification boundary of motion modes is presented. The results indicate that, when subjected to underwater pressure pulse loading, the mass block repeatedly collides with the constraint boundary and undergoes non-periodic motion. With higher loading pressure amplitude and duration, the mass block is more likely to collide with the back boundary, leading to a transition in movement modes from mode (i), mode (ii), mode (iv) to mode (v). Increasing the stiffness coefficient and areal density will increase the threshold of ϕ and ψ for the transition from mode (i) to mode (v), while the maximum allowable displacement has little effect on the classification boundaries. These research findings are valuable for analysing the motion response of mass spring with various constraint boundaries under dynamic loading, and for guiding the design of spring-loaded valves.