External Work Research Articles

Physically Based Constitutive Modeling of Dynamic Strain Aging in C45 Steel

Abstract Dynamic strain aging (DSA) is a sudden increase in the strength of a material under certain combinations of temperatures and strain rates. Despite the phenomenon being reported in several other studies, the literature still lacks a specific constitutive model that can physically interpret its effect. Therefore, this work proposes a modification based on physical parameters to the Voyiadjis and Abed (VA) model to account for the effect of DSA in C45 steel. The resulting modified model is then coupled with an energy-based damage model to further capture the effect of material softening. Previously, in VA model, it was assumed that the total activation energy for overcoming the obstacles without external work remains the same which works well in the absence of DSA. However, during DSA, the mobile dislocations are pinned by the diffusing solute atoms. This results in an increase in the total activation free energy needed by the dislocations to overcome the obstacle. Thus, an increase in strength is observed. It is shown in the current work that utilizing the concept of increased solute concentrations at local obstacles, in conjunction with the physical description that the VA model is based upon, successfully captures the phenomenon of DSA in C45 steel. In addition, the metal experiencing softening after reaching its ultimate strength is due to the significant growth of voids and cracks within the microstructure. To capture this behavior, an energy-based damage parameter is incorporated into the proposed model. The coupled plasticity-damage model shows a good comparison with the experimental results.

Research on the English Translation of Political Texts from the Perspective of Eco-translatology: A Case Study of Government Work Report in 2023

As China’s economy and society develop and its international influence continues to grow, foreign governments and people are paying more attention to China. In this context, foreign publicity work is of great significance for the world to "understand China". As an effective carrier of external publicity work, the political texts translation covers China's current development status, major policies, and strategic plans. Therefore, its importance is self-evident. Based on the ecological translation theory, this study takes the English translation of the 2023 Government Work Report as an example to explore how to interpret China's path and demonstrate cultural confidence in political texts translation, thereby achieving communicative purposes. The study found that translators often use translation strategies such as conversion of parts of speech, extension, and omission to achieve adaptive selection in the three dimensions of language, culture, and communication in order to achieve an ecological balance between the source and the target language culture, thereby enhancing the appeal and credibility of China's discourse in foreign publicity work.

Endoscopic mucosal resection and endoscopic submucosal dissection with an external additional working channel (EMR+ and ESD+) are equivalent to using a double-channel endoscope: a systematic evaluation in a porcine ex vivo model.

With an external additional working channel (AWC) endoscopic mucosal resection (EMR) as well as endoscopic submucosal dissection (ESD) can be extended to techniques termed "EMR+" and "ESD+." These novel techniques are systematically compared to EMR and ESD under the use of a double-channel endoscope (DC). Our trial was conducted prospectively in a pre-clinical porcine animal model (EASIE-R simulator) with standardized gastric lesions measuring 3 or 4cm. EMR+ and EMR DC showed both good results for 3cm lesions with no adverse events and an en bloc resection rate of 73.33% (EMR+) and 60.00% (EMR DC, p = 0.70). They came to their limits in 4cm lesions with muscularis damages of 20.00% (EMR+), 13.33% (EMR DC, p ≥ 0.99) and decreasing en bloc resection rates of 60.00% (EMR+) and 46.67% (EMR DC, p = 0.72). ESD+ and ESD DC were both reliable concerning en bloc resection rates (100% in all groups) and adverse events (0.00% in 3cm lesions, 12.50% muscularis damages in both ESD+ and ESD DC in 4cm lesions). Resection time was slightly shorter in all groups with the AWC compared to DC although only reaching significance in 3cm ESD lesions (p < 0.05*). With the AWC, a standard endoscope can easily be transformed to double-channel functionality. We could show that EMR+ and ESD+ are non-inferior to EMR and ESD under the use of a double-channel endoscope. Consequently, the AWC presents an affordable alternative to a double-channel endoscope for both EMR and ESD.

Electrical discharge and arc milling with automatic tracking of optimal flushing direction: A novel high-efficiency compound machining method

The arc milling method has the advantages of high machining efficiency and low cost and is independent of the strength and hardness of machined materials. However, frequent electrode back-offs and the risk of workpiece burning may occur if erosion products are not removed promptly. In this study, it was found that the flushing method of the working medium had a significant impact on the machining performance of arc milling. Based on this, a novel high-efficiency compound machining method of electrical discharge and arc milling with automatic tracking of the optimal flushing direction was proposed. An automatic tracking optimizer for external working medium injection was designed to determine the optimal external flushing direction according to the feed direction. The influence of flushing methods, working mediums, and machining parameters on the machining efficiency, tool electrode wear rate, machining error, and surface integrity of titanium alloys were investigated. The results indicated that better machining performance and environmental friendliness were achieved using the compound flushing method of outer compressed air and inner deionized water. Additionally, the automatic tracking flushing method in the opposite direction of the feed direction showed superior results compared to other directions. The material removal rate with the opposite direction injection could be increased up to 1.62 times that of the same direction, and the relative electrode wear rate could be reduced by 14.76%. This novel method has broad application prospects for machining parts with difficult-to-cut materials in aerospace and military industries.

Analytical and numerical determination of the forming load in the Chain-die forming process

Recently there has been a growing demand for Advanced High-Strength Steel (AHSS) in the automotive sector because it can offer similar strength and crash resistance at a lower mass. However, conventional manufacturing is having trouble processing AHSS, and many technical issues such as substantial residual strains and unpredictable springback arose during the process. Thus, a new forming technique Chain-die forming was developed to address this situation. Past research has shown the advantage of the Chain-die forming method. However, systematic research and more case studies should be done to further explore the feasibility of the Chain-die forming in industrial practice. In this work, two fast estimation of the forming load methods are proposed. The first method estimates the forming load experienced by the forming device by superimposing the duplicated load curve extracted from a two-dimensional stamping simulation. The second method is an analytical model considering the stretching and bending behaviour of the sheet metal during forming. It is established using the internal deformation energy and the geometric relationship of the toolings and forming devices. Furthermore, this analytical model is based on equating the external work to the internal dissipation of the energy to estimate the forming load. The estimated results have been verified with the experimental data and show good agreement. The findings of this study can be implemented in the future development of Chain-die forming to improve the efficiency of the design and optimisation process.

Responding to crisis and emergencies – Linking employee characteristics to levels of satisfaction with governance, procedures & mechanisms

Government strategies and response mechanisms adopted during the global crisis of the Covid-19 pandemic are now under ever increasing scrutiny to understand what did or did not contribute to successful response outcomes. The Emirate of Abu Dhabi in the United Arab Emirates is by many measures ranked as a world leading model for the application of their crisis and emergency management procedures in response to the Covid-19 pandemic. A case study (including 6000+ survey respondents) to explore the relationship between the characteristics (age, qualification, length of service, position, business sector) of employees in the Emirate's local authorities and their level of satisfaction with the preparedness, and application of the National Crisis and Emergency Management Authority (NCEMA) response mechanisms was conducted post-Covid-19. The findings indicate in respect of the highest levels of satisfaction recorded within demographic groupings, the youngest (18–23 years) age group at 94.4%, the more experienced working group at 89.6%, and those from the health sector at 88% with the application of the NCEMA mechanisms. The range of difference at 7.66% was identified for the participants' academic demographic and levels of satisfaction with the NCEMA mechanism applications. Respondents in the education and social development sectors indicated less familiarity, knowledge and understanding of crisis and emergency management. The study offers insight into the governance of internal and external working relationships, employee familiarity and operational knowledge of crisis and emergency management that result in achieving successful levels of preparedness and response outcomes for the safety and security of the community.

Implications of sustainability reporting and institutional investors’ ownership for external audit work: evidence from Saudi Arabia

Purpose This study aims to assess whether non-financial corporate social responsibility (CSR) information decreases audit risk and audit scope and enables speedier completion of audit reports. The study also investigates whether institutional investors’ ownership (IIO) has an influence on the association between CSR disclosures and audit report lag (ARL). Design/methodology/approach This study uses a sample of 154 Saudi firms over 2016–2021 (837 observations) and applies ordinary least square regression to examine the study hypotheses. Findings This study’s results show that ARL is significantly shorter for firms with higher CSR disclosures. Furthermore, the findings show that IIO has no significant impact on the association between CSR disclosures and ARL. Originality/value This study offers new insights into how auditors respond to CSR disclosures and whether institutional investor monitoring influences the audit process in an emerging economy.

Enhancing interfacial shear debonding resistance by mechanical mismatch

Layered systems of similar/dissimilar soft materials are widely used in advanced device applications, including bioelectronics, soft robotics, and energy generators. Device designers strive to minimize the mechanical mismatch between the soft material layers, claiming that the mismatch could be associated with low interfacial debonding resistance and then cause device malfunction. Although strong interfacial bonding has been repeatedly achieved based on the principle of minimizing-mechanical-mismatch, the specific question of whether mechanical matching is the optimal solution for high debonding resistance has never been solidly answered, leaving ambiguity in the further optimization of the layered soft material systems. In this paper, the influence of the stiffness ratio between the soft material layers on the interfacial shear debonding resistance is systematically analyzed through theoretical modeling and finite element simulation approaches. Monotonic improvement of the shear debonding resistance with increasing the loading layer stiffness, even when exceeding that of the substrate layer, is analytically derived by establishing a shear debonding theory of a hyperelastic bilayer. This mechanical-mismatch induced improvement is due to the effective consumption of the external work by the strain energy storage of the loading layer and the large increase in the shear lag length. The theoretical predictions of the debonding resistance agree well with the finite element simulation results, which implies the local non-uniform deformation in the loading and substrate layers near the interfacial crack front causes insignificant influence on the shear debonding. Increasing the modulus or thickness of the loading layer or adding a stiff backing can equivalently improve the shear debonding resistance, which can be quantitatively predicted by the established shear debonding theory. Reasonable applications of the proposed debonding resistance enhancement strategy are also discussed. The findings provide good guidance for the safe service and further optimization of the layered soft material systems to improve the device reliability.

Summary of Health-State Estimation of Lithium-Ion Batteries Based on Electrochemical Impedance Spectroscopy

With the increasing application of lithium-ion batteries, accurate estimation of the state of health (SOH) of lithium-ion batteries is of great significance for the safe operation of lithium-ion battery systems and the reduction of operation and maintenance costs. The complex physical and chemical reactions inside the lithium battery and the complex external working conditions make it challenging to achieve an accurate health-state estimation and life prediction. Therefore, the accurate estimation of the SOH of lithium-ion batteries is an important issue. At present, electrochemical impedance spectroscopy (EIS) is widely used in the study of battery-power impedance characteristics and battery-state estimation due to its advantage of nondestructive measurement. For this reason, this paper summarizes the research progress of lithium-ion SOH estimation based on EIS in recent years and details it layer by layer, mainly from two aspects: first, the quantitative relationship model between the characteristic parameters and SOH is established by constructing a frequency domain-equivalent circuit model. Secondly, we construct a quantitative relationship model between EIS data and SOH using the data-driven method. Finally, the advantages and disadvantages of different methods and estimation accuracy are analyzed and compared, and the future estimation of SOH based on EIS is prospected.

Predicting lameness in dairy cattle using untargeted liquid chromatography–mass spectrometry-based metabolomics and machine learning

Lameness in dairy cattle is a highly prevalent condition that impacts on the health and welfare of dairy cows. Prompt detection and implementation of effective treatment is important for managing lameness. However, major limitations are associated with visual assessment of lameness, which is the most commonly used method to detect lameness. The aims of this study were to investigate the use of metabolomics and machine learning to develop novel methods to detect lameness. Untargeted metabolomics using liquid chromatography-mass spectrometry (LC-MS) alongside machine learning models and a stability selection method were utilized to evaluate the predictive accuracy of differences in the metabolomics profile of first-lactation dairy cows before (during the transition period) and at the time of lameness (based on visual assessment using the 0-3 scale of the Agriculture and Horticulture Development Board). Urine samples were collected from 2 cohorts of dairy heifers and stored at -86°C before analysis using LC-MS. Cohort 1 (n = 90) cows were recruited as current first-lactation cows with weekly mobility scores recorded over a 4-mo timeframe, from which newly lame and nonlame cows were identified. Cohort 2 (n = 30) cows were recruited within 3 wk before calving, and lameness events (based on mobility score) were recorded through lactation until a minimum of 70 d in milk (DIM). All cows were matched paired by DIM ± 14 d. The median DIM at lameness identification was 187.5 and 28.5 for cohort 1 and 2, respectively. The best performing machine learning models predicted lameness at the time of lameness with an accuracy of between 81 and 82%. Using stability selection, the prediction accuracy at the time of lameness was 80 to 81%. For samples collected before and after calving, the best performing machine learning model predicted lameness with an accuracy of 71 and 75%, respectively. The findings from this study demonstrate that untargeted LC-MS profiling combined with machine learning methods can be used to predict lameness as early as before calving and before observable changes in gait in first-lactation dairy cows. The methods also provide accuracies for detecting lameness at the time of observable changes in gait of up to 82%. The findings demonstrate that these methods could provide substantial advancements in the early prediction and prevention of lameness risk. Further external validation work is required to confirm these findings are generalizable; however, this study provides the basis from which future work can be conducted.

Translation for International Publicity News: A Perspective of Cross-Cultural Pragmatics

Under the trend of global integration, international exchanges are becoming more and more thorough, and international publicity of China has been strengthened and expanded. As a powerful tool for international communication, international publicity news has attracted more attention to the selection and use of news content translation methods. Chinese international publicity work has produced great results in recent years, but the good and bad translations are intermingled. Due to the barrier of cross-cultural, “Chinglish” can be found in some translations, which not only impose a negative impact on the external publicity work, but also is not conducive to the objective and correct understanding of China in the world. From the perspective of cross-cultural pragmatics, this paper selects the international publicity news and translation method as the research object. The author makes a systematic study on the C- E (from Chinese to English) translation of publicity news. Based on the study of cross-cultural pragmatics and the characteristics of publicity news, the purpose is to make the original and the target discourses share the same function in communication. Therefore, to achieve effective and accurate publicity news translation and improve the quality in publicity news translation in order to better disseminates the culture in both sides.

Programme Leadership and Stress Experiences by Graduate Students in Selected Christian Universities in Kenya

Stress cuts across all humanity and students are habitually confronted with academic challenges that cause them stress, as manifested by problems such as mental health which often led to withdrawal from studies. This study sought to examine stress experiences due to programme leadership among graduate students in selected Christian universities in Kenya. A mixed-method approach was used for the study. A sample of 142 graduate students selected proportionately from four (4) Christian universities in Kenya took part in the study. The study results showed that within the programme leadership, supervision of dissertation was causing stress among graduate students. Supervisors were taking long to give feedback to students, which led to students being anxious and as such was causing perceived stress. However, various underlying external factors, especially negative external work engagement, financial challenges, and lack of teamwork with fellow students which were also being experienced could be other underlying factors aggravating the stress among the students. It is therefore recommended that supervisors need to give timely feedback to students. It is further recommended that students should be prepared to finance their graduate studies right from the onset, and to manage their workplace engagements, as well as being able to work as a team. The findings of this study are useful in helping students understand how the learning environment contributes to their stress, and hence finding appropriate ways of coping with it. Secondly, the study informs policymakers at the institutional level of actions to take for reviewing their systems to enhance a conducive environment for graduate students to cope with stress.

The effect of increasing work rate amplitudes from a common metabolic baseline on the kinetic response of V̇O2p, blood flow, and muscle deoxygenation.

A step-transition in external work rate (WR) increases pulmonary O2 uptake (V̇O2p) in a monoexponential fashion. While the rate of this increase, quantified by the time constant (τ), has frequently been shown to be similar between multiple different WR amplitudes (ΔWR), the adjustment of O2 delivery to the muscle (via blood flow; BF), a potential regulator of V̇O2p kinetics, has not been extensively studied. To investigate the role of BF on V̇O2p kinetics, ten participants performed step-transitions on a knee-extension ergometer from a common baseline WR (3 W) to: 24, 33, 45, 54, and 66 W. Each transition lasted 8 min and was repeated 4-6 times. Volume turbinometry and mass spectrometry, Doppler ultrasound, and near-infrared spectroscopy were used to measure V̇O2p, BF, and muscle deoxygenation (deoxy[Hb+Mb]), respectively. Like transitions were ensemble-averaged and phase II V̇O2p, BF, and deoxy[Hb+Mb] were fit with a monoexponential non-linear least squares regression equation. With increasing ΔWR, τV̇O2p became larger at the higher ΔWRs (p < 0.05), while τBF did not change significantly, and the mean response time (MRT) of deoxy[Hb+Mb] became smaller. These findings that V̇O2p kinetics become slower with increasing ΔWR, while BF kinetics are not influenced by ΔWR, suggest that O2 delivery could not limit V̇O2p in this situation. However, the speeding of deoxy[Hb+Mb] kinetics with increasing ΔWR does imply that the O2 delivery-to-O2 utilization of the microvasculature decreases at higher ΔWRs. This suggests that the contribution of O2 delivery and O2 extraction to V̇O2 in the muscle change with increasing ΔWR.

Seismic Stability Limit Analysis of Unsaturated Soil Slopes Reinforced by Frame Beam Anchor Plates

The frame beam anchor plate (FBAP) reinforced slope has been popularized and applied in some fill slope projects. Nevertheless, the existing design method ignores the influence of earthquake action and the suction effect of unsaturated soils. The stability of unsaturated soil slopes reinforced with FBAPs under an earthquake is analyzed based on the upper bound theorem of limit analysis and pseudo-dynamic method to solve the above problems. The influence of the suction effect on the effective weight and strength of unsaturated soils under one-dimensional steady seepage conditions was considered in the derivation of the energy balance equation. A simplified method based on the volume integral of the rotating body is used to calculate the external work rate. Two possible failure modes of anchorage structures are considered when solving internal energy dissipation. Results show that the influence of suction and seepage conditions on slope stability decreases with the increasing soil pore size distribution parameter n and saturated hydraulic conductivity ks. Also, the stability of the slopes is significantly improved with the increase of total rows of anchor plates. Likewise, the stability of slopes decreases with the increase in the horizontal seismic coefficient kh and amplification coefficient fa.

Mechanism analysis on suppressing porosity in laser-MIG hybrid welding of aluminum alloy via external magnetic field

An external magnetic field with a high magnetic flux density (≥300 mT) has been proven to reduce the porosity of aluminum alloy single laser welded joints. However, the additional welding current exists in laser-arc hybrid welding (LAHW) and its physical mechanism of interaction between the external magnetic field and the molten pool is different from magnetic-assisted laser welding. It was explored whether the porosity suppression of the external magnetic field works in LAHW using experimental observation and numerical simulation. The results suggested that the presence of an arc would induce the interaction between the magnetic field with a lower magnetic flux density and welding current, giving rise to a strong backward Lorentz force up to 1.44 × 105 N/m3, which differed from that in the magnetic-field-assisted laser welding. Although the presence of an arc heat source extended the solidification time of the rear weld pool. The impact of the droplet on the rear keyhole wall deteriorated the keyhole stability and caused severe keyhole collapse. Additionally, some vortices also deformed the keyhole rear wall and prevented the escape of bubbles in LAHW, leading to a greater porosity rate of 13.7 %. However, the impact of the droplet was weakened and vortices were reduced when an external magnetic field of 24 mT was used, which significantly decreased the porosity rate of LAHW to 2.0 %. This study will provide a more underlying understanding of magnetic-field-assisted welding and widen the industrial application of LAHW.

Factors impacting strategic management accounting adoption: Empirical evidence from an emerging market

Strategic management accounting (SMA) is an advanced management tool that provides valuable information to aid managers in making strategic decisions for both long-term and short-term choices. Many factors motivated managers to adopt strategic management accounting (SMA) practices in their enterprises. Furthermore, strategic management accounting (SMA) techniques also consider external stakeholders such as customers, suppliers and regulators. Therefore, there may be various aspects of the external working environment that impact SMA implementations. On the other hand, strategic management accounting (SMA) also helps managers manage costs and resources effectively. Other internal factors such as managers’ perceptions about SMA, the knowledge of accountants and technologies also significantly impact the adoption of SMA techniques. The study’s main objective is to investigate the factors that affect SMA implementation in Vietnamese enterprises. Purposive techniques are used in the study’s explorative quantitative survey approach and data collection. Data from 305 Vietnamese enterprises are included in the sample. The findings demonstrate that the adoption of SMA practices is positively associated with four factors including top management teams, corporate culture, perceived environmental uncertainty and management networking.

Coupled effect of pulsed current and ultrasonic vibration on deformation behavior of Inconel 718 sheet: phenomena and modeling

Multi-energy fields provide higher dimensional precision control and desirable performance for microforming processes. The constitutive model under low strain level was established to describe the coupled effect of pulsed current and ultrasonic vibration based on the Kocks-Mecking (K-M) model. Combined with the crystallographic theory, the model introduced acoustic softening effect and electroplastic effect, and described the interaction between pulsed current and ultrasonic vibration under coupled field from the perspective of energy absorption. In the research, the uniaxial tensile test of Inconel 718 sheet with thickness of 0.3 mm was carried out. The ranges of the current density and ultrasonic energy density were 20.9–50.9 A mm−2 and 15.84–57.64 J cm−3, respectively. The results showed that: the facilitation of ultrasonic vibration on dislocation generation was limited with the increase of strain, and the energy generated by ultrasonic vibration was more reflected in the change of Helmholtz free energy; when the energy generated by the current at athermal condition tended to be saturated, the increase of heat became the key to improve the electroplasticity, and the heating model caused by Joule heating effect was established. The constitutive model of coupling electric pulse and ultrasonic treatment was established, combining the characteristics of ultrasonic vibration and pulsed current; the flow stress was described by using the parameters of ultrasonic energy density and current density; The trigonometric function was used to quantitatively describe the competitive relationship between ultrasonic vibration and pulsed current in external work. Two sets of experiments were used to demonstrate the reliability of the model.

Determining large-strain metal plasticity parameters using in situ measurements of plastic flow past a wedge

We present a novel approach to determine the constitutive properties of metals under large plastic strains and strain rates that otherwise are difficult to access using conventional materials testing methods. The approach exploits large-strain plastic flow past a sharp wedge, coupled with high-speed photography and image velocimetry to capture the underlying plastic flow dynamics. The inverse problem of estimating material parameters from the flow field is solved using an iterative optimization procedure that minimizes the gap between internal and external plastic work. A major advantage of the method is that it neither makes any assumptions about the flow nor requires computational simulations. To counter the problem of non-unique parameter estimates, we propose a parameterization scheme that takes advantage of the functional form of the constitutive model and reformulates the problem into a more tractable form to identify plasticity parameters uniquely. We present studies to illustrate the principle of the method with two materials with widely different plastic flow characteristics: copper (strain hardening) and a lead-free solder alloy (rate sensitive and deformation history dependent). The results demonstrate the efficacy of the method in reliably determining the material parameters under high strain/strain rate conditions of relevance to a range of practical engineering problems.

On Approaches to Designing a “Vivid” Economy

The study examines approaches to designing an economy capable of life. The purpose of the article is to obtain criteria that satisfy such an economy. The hypothesis is the idea of the ability of the economy to self-propulsion due to the continuous exchange between its elements. Information and knowledge are considered as a universal category that takes part in the processes of exchange. Hence the problem of stability in complex open nonlinear systems is emphasized; a definition is given for the ultra-sustainability of the economy – ​the economy bypasses those states that can lead to a change in sustainability. The author sees the result of the study of the potential for ultra-sustainability in the “vivid” components of the economy: the ability of the economic system to interact with lower and higher levels in the hierarchical structure; definition of meanings and goal setting; prioritization in safety and evolution; subjectivity; production and application of knowledge; processing external chaos and working into its own complexity; functioning feedbacks; the presence of a strong-willed and effective component; accountability mechanism. The research method consists in referring to a systematic and synergistic approach, which makes possible to explain the phenomenon of homeostasis in the economy. Intermediate conclusions are obtained: information and knowledge components can act as a unifying element for exchange processes in the economy. The conclusion that self-completion of a holistic image of the national economy can be carried out with the help of knowledge, which act as a driving and structuring force, is proposed for discussion in economic science.

Exact Dirichlet boundary Physics-informed Neural Network EPINN for solid mechanics

Physics-informed neural networks (PINNs) have been rapidly developed for solving partial differential equations. The Exact Dirichlet boundary condition Physics-informed Neural Network (EPINN) is proposed to achieve efficient simulation of solid mechanics problems based on the principle of least work with notably reduced training time. There are five major building features in the EPINN framework. First, for the 1D solid mechanics problem, the neural networks are formulated to exactly replicate the shape function of linear or quadratic truss elements. Second, for 2D and 3D problems, the tensor decomposition was adopted to build the solution field without the need of generating the finite element mesh of complicated structures to reduce the number of trainable weights in the PINN framework. Third, the principle of least work was adopted to formulate the loss function. Fourth, the exact Dirichlet boundary condition (i.e., displacement boundary condition) was implemented. Finally, the meshless finite difference (MFD) was adopted to calculate gradient information efficiently. By minimizing the total energy of the system, the loss function is selected to be the same as the total work of the system, which is the total strain energy minus the external work done on the Neumann boundary conditions (i.e., force boundary conditions). The exact Dirichlet boundary condition was implemented as a hard constraint compared to the soft constraint (i.e., added as additional terms in the loss function), which exactly meets the requirement of the principle of least work. The EPINN framework is implemented in the Nvidia Modulus platform and GPU-based supercomputer and has achieved notably reduced training time compared to the conventional PINN framework for solid mechanics problems. Typical numerical examples are presented. The convergence of EPINN is reported and the training time of EPINN is compared to conventional PINN architecture and finite element solvers. Compared to conventional PINN architecture, EPINN achieved a speedup of more than 13 times for 1D problems and more than 126 times for 3D problems. The simulation results show that EPINN can even reach the convergence speed of finite element software. In addition, the prospective implementations of the proposed EPINN framework in solid mechanics are proposed, including nonlinear time-dependent simulation and super-resolution network.