Deformation Distribution Research Articles

Two-Dimensional Numerical Method for Predicting the Resistance of Ships in Pack Ice: Development and Validation

This study presents a 2D numerical simulation method for predicting the resistance of ships navigating in pack ice. The key contribution of this study lies in the derivation of analytical closed-form solutions for calculating the flexural deformation and stress distribution in an elastic plate using Symplectic Mechanics and Hooke’s laws. These solutions are used to determine the failure mode of ice floes. Linear Elastic Fracture Mechanics (LEFMs) and the weight function method are utilized to analyze crack initiation, propagation, and fracture. Ice is broken when a crack propagates to 14.5% of the ice length. The compressive strength of ice and the contact area are used to calculate the ice load. A collision method was developed based on the Sweep and Prune (SAP) and Gilbert–Johnson–Keerthi (GJK) algorithms. A program for predicting the resistance of ships navigating in pack ice was developed based on MATLAB and the aforementioned theories. The navigation resistance of RV Xuelong at different ice concentrations and speeds was simulated and compared with the model test results from an ice tank. The comparison shows that the simulation results are consistent with the test results, with an average error of 9.05%, indicating the effectiveness and reliability of this numerical method. This study lays a solid foundation for future research on autonomous ship navigation in pack ice.

Stress calculation and strength verification of desulfurization and denitrification tower based on carbon-based catalytic multi-pollutant control technology

The desulfurization and denitrification tower is the core equipment of the carbon-based catalytic multi-pollutant collaborative control technology. Its design strength ensures the pollutant removal effect and stable operation of the system. This paper used ANSYS finite element analysis software to establish a three-dimensional model of the tower and divided it into high-precision grids. Combined with actual load analysis, calculation and working condition combination, the deformation and stress distribution nephogram of the tower and the membrane stress and bending stress of each component were calculated. The strength check and stress assessment were carried out. When the calculation error is ignored, the overall design strength of the tower meets the requirements, but the stress of the local reinforced beams exceeds the limit. It is recommended to replace the steel with a higher allowable stress value.

Crustal deformation in East of Cairo, Egypt, induced by rapid urbanization, as seen from remote sensing and GNSS data

Abstract The area located East to Cairo, the Capital of Egypt, represents an obvious example for the rapid urban expansion, as it contains many new housing cities. Beside its socio-economic importance, it’s located in the Cairo-Suez seismic zone. We utilized Persistent Scatterer Interferometry (PSI) of 2015–2021 Sentinel-1 SAR scenes along with two GNSS stations (KATA and PHLW) to assess the distribution and rates of crustal deformation of this region. The PSI analysis is applied to 140 Sentinel-1 SAR images collected from the ascending track number (58) and the descending track number (167). The Bernese software V. 5.0 is used for the processing of the GNSS data. A good agreement between the rates estimated from the PSI analysis and GNSS data is observed. Based on results, most of the new cities showing land subsidence with variable rates. The rates at Obour, New Cairo, Shorouk, Madinty, and Capital Gardens are 0.54 ± 0.30 mm/year, 0.58 ± 0.30 mm/year, 1.01 ± 0.30 mm/year, 0.58 ± 0.30 mm/year, and 0.99 ± 0.30 mm/year, respectively. The highest recorded subsidence rates are at Asher, Administrative Capital, and Badr with 2.18 ± 0.30 mm/year, 1.89 ± 0.30 mm/year, and 1.69 ± 0.30 mm/year, respectively. Nasr city is the only city with an uplift of 0.82 ± 0.30 mm/year. Our new findings introduce the probable use of integrated techniques such as GNSS and InSAR to evaluate the extent of crustal deformation connected to rapid urbanization in arid areas. Beside tectonic setting, it should be considered while executing mega-projects for sustainable development especially within Egypt’s Vision 2030.

Laboratory experimental study on GESC combined with electroosmosis for ground improvement

To verify the effect of electrokinetic geosynthetics-encased stone columns combined with electroosmosis on soft soil foundation reinforcement, laboratory model experiments were conducted using stone columns (SC), geosynthetics-encased stone columns (GESC) with/without electroosmosis. The energy consumption coefficient and drainage rate of electroosmosis, the shear strength and water content distribution of soil, and deformation law of the pile section after static load tests at different depths were studied. Experimental results show the strength of soil around the pile increases after electroosmosis, enabling better support for the pile body, while the pile-soil stress ratio of the gravel pile is reduced and the side friction resistance is effectively exerted. Moreover, the expansion deformation distribution of the gravel pile in both the E-GESC and GESC configurations is basically the same, and the maximum radial deformation is less than that observed in the SC. Most of the deformation occurs within a range of 2 times the pile diameter below the boundary line of the wrapped section. The ultimate bearing capacity of the composite foundation formed by the electroosmosis with geosynthetics encased stone columns (E-GESC) method is 6.6 times that of the SC and 3.8 times that of the GESC, demonstrating a significantly enhanced reinforcement effect.

Fracture process zone and fracture energy of heterogeneous soft materials

Bio-inspired heterogeneous soft materials are under rapid development due to their superior fracture and fatigue resistance. In the last few years, several kinds of fibrous soft composites in different length scales have been fabricated. However, the fracture behavior and toughening mechanism of this class of materials are still elusive. Here we develop a theoretical model for the crack tip field of fiber reinforced soft composites. The distribution of deformation around the crack tip and released elastic energy during crack propagation are obtained. The fracture process zone and fracture energy are quantified. There is a critical sample height, below which the fracture process zone size and fracture energy are size-dependent, above which they approach material-specific constants: steady-state fracture process zone size and steady-state fracture energy. A formula is derived to relate the steady-state fracture process zone size and parameters of the composite. It is found that both the steady-state fracture process zone size and the critical sample height scale with the fractocohesive length of the composite. The steady-state fracture energy of the composite can be enhanced either by enlarging the fracture process zone size through tuning fiber geometry or by increasing the work to rupture of the fiber through chemical treatment. This work reveals the toughening mechanism of heterogeneous soft materials and paves the way to design soft materials of high fracture energy, high fatigue threshold, and low hysteresis. It also provides a practical guideline for determining the sample size to measure the steady-state fracture energy of heterogeneous soft materials.

SUBSTANTIATION OF THE REGULARITIES OF THE SUBGRADE STRESS-STRAIN STATE AFTER THE IMPLEMENTATION OF THE EUROPEAN TRACK

Purpose. The implementation of the European track (1435 mm) on the existing subgrade, built on the territory of Ukraine, is a factor that leads to a change in the stress-strain state. The purpose of the article is to substantiate the regularities of the stress-strain state of the subgrade based on the results of numerical analysis of finite-element models. Methodology. For numerical analysis based on the finite element method, a 6 m high subgrade model for the combined track was developed. The developed model reproduces all the real geometric characteristics of the subgrade, the upper structure of the track, as well as the sleeper for the combined track. The developed model allows to vary the application of the train load with the setting of a couple of forces on the rails, which have the Ukrainian value of the track gauge (1520 mm), as well as the European one. The model also simulates the reinforcement of the subgrade for four options (without pile, with pile length of 2.0, 4.0 and 6.0 m). Findings. The results of the numerical analysis made it possible to obtain the values of horizontal and vertical stresses, as well as to obtain the regularities of the stress-strain state of the subgrade before the introduction of the European track. Qualitative analysis of the train position shows that the reduction of the track gauge and its asymmetric location on the sleeper increases vertical deformations. The biggest problem is precisely the asymmetric distribution of vertical displacements. It was found that the increase in the length of the vertical reinforcement element provides a reduction in displacements by 1.1 … 1.2 times. It was found that the patterns of changes in the displacements of the subgrade, when the length of the vertical reinforcement element is varied, are linear for the horizontal component and polynomial of the second degree for the vertical component. Originality. For the first time, based on the regularities of the stress-strain state of the subgrade, a picture of the stresses formation and the distribution of deformations before and after the implementation of the European track was obtained. Practical value. Based on the results of the numerical analysis, it was found that increasing the length of the vertical reinforcement element by 2.0 m provides a reduction in displacements by 10 … 20 %. This data makes it possible to create a methodology for the initial selection of the reinforcement element parameters.

Topological Properties of Network Spring Models that Determine Terminal Distributions of Plastic Deformations

Topological Properties of Network Spring Models that Determine Terminal Distributions of Plastic Deformations

The generation method of orthophoto expansion map of arched dome mural based on three-dimensional fine color model

Murals carry cultural significance and historical information, and are an important channel for understanding ancient social norms, artistic styles, and religious beliefs. At present, the digitization of murals is an important technical means for the protection of cultural heritage. Orthogonal images of murals play a vital role in high-precision recording, preservation, academic research, educational expansion, mural protection, digital exhibition and dissemination. At present, orthogonal images of murals are mostly realized by plane projection, but this method is not suitable for making orthogonal images of arched and dome-shaped murals. To address this problem, this paper proposes a method for generating orthogonal expansion images of arched and dome-shaped murals. This method combines a three-dimensional virtual space simulation model with an RTT virtual camera and adopts a spatial reference orthogonal ray scanning model. First, the detailed three-dimensional color model is fitted to the geometric reference of cylindrical and spherical objects to determine its parameters. Next, for the cylindrical murals on the arch, the orientation of the model is initialized using quaternions, and the viewport matrix is adjusted to obtain the required resolution. Then, the RTT camera is used to perform line orthogonal projection in the viewport, and the fringe projection image is generated by rotating around the cylinder axis according to the inversely calculated rotation angle. For the murals on the dome ceiling, this method is used to segment them according to a certain longitude, and the circumscribed cylinder of the fitted sphere is rotated to perform cylindrical orthogonal line scanning in the segmented area. These individual orthogonal line scan images are carefully spliced together to form a complete orthogonal unfolded image. Finally, a fringe projection image is generated with the central meridian of the unfolded part as the center line, and the fringe projection images are spliced together to obtain the final orthogonal unfolded image. Experiments show that compared with existing methods, this method can generate two-dimensional orthogonal unfolded images with high texture fidelity, minimal texture deformation, and uniform deformation distribution. This study provides a novel perspective on the orthogonal unfolding of quasi-cylindrical and quasi-spherical painted objects, and provides an accurate and diverse data basis for the digitization of murals.

Thermo-Mechanically Coupled Settlement and Temperature Response of a Composite Foundation in Complex Geological Conditions for Molten Salt Tank in Tower Solar Plants

The degradation of complex geological structures due to thermo-mechanical cycling results in a reduction in bearing capacity, which can readily induce engineering issues such as uneven settlement, cracking, and even the destabilization of the foundations of molten salt storage tanks. This study establishes a foundational model for a molten salt storage tank through the use of COMSOL Multiphysics and conducts a numerical simulation analysis to evaluate the settlement deformation and temperature distribution of the foundation under the influence of thermo-mechanical coupling. Concurrently, the research proposes two distinct design approaches for the tank’s foundational structure. A comparative analysis of the results indicates that the use of a pile raft foundation in conjunction with a traditional foundation mode results in a reduction of settlement at the center of the foundation’s top surface by 380.1 mm, while also decreasing the maximum effective stress in the steel ring wall by 240.7 MPa. The thermal effects impact a depth of 10 m in the foundation soil and an influence radius of 20 m. Additionally, the foundation soil exhibits optimal thermal insulation properties, resulting in minimal energy loss. These findings indicate that the pile raft foundation in conjunction with a traditional foundation mode displays remarkable adaptability to complex geological conditions, with both settlement and temperature distribution of the foundation maintained within acceptable limits.

Significantly enhanced mechanical properties of NiCoV medium-entropy alloy via precipitation engineering

Precipitation engineering is one of the most effective means to enhance the strength of an alloy, which essentially requires precipitates with certain deformability, fine size, and uniform distribution. However, for multicomponent alloy systems, the chemical complexity poses significant difficulties in applying this strengthening method due to the diversity and brittleness of the potential precipitate phases. In this work, we demonstrated the precipitation engineering in a chemically complex prototype alloy NiCoV. Specifically, formation of detrimental σ, μ and Heusler phases was avoided by reducing the V content, and a two-step short-term annealing was designed to trigger homogeneous κ nucleation while inhibiting its rapid coarsening. It is found that both grain and phase boundaries can trap V atoms, which not only pins these interfaces but also hinders the V partitioning needed for κ growth. Consequently, we achieved an ultrafine κ/γ architecture in the NiCoV0.9 alloy, which surprisingly exhibited an ultrahigh yield strength of 1.6 GPa and a total work-hardening amount of 219 MPa. Our analysis indicates that the hetero-deformation induced (HDI) stress is mainly responsible for the high strength, while the coherent nature of phase boundaries and decent deformability of κ alleviate stress concentration, giving rise to the pronounced work-hardening. Our work highlights the importance of suitable phase selection and delicate substructure tailoring in precipitation engineering, with key findings also useful for enhancing overall mechanical properties in other multicomponent alloys.

Surface forming mechanism and numerical simulation study in four-roll flexible rolling forming

This study investigates the surface forming mechanism in four-roll flexible rolling forming processes, addressing issues of low efficiency and significant residual stresses, particularly when dealing with lightweight high-strength materials such as LY12 aluminum alloy. Initially, the study systematically analyzes the variation in sheet curvature radius under different forming methods, considering the separate and combined actions of side rolls and flexible rolls in the pre-bending forming process. Subsequently, actual forming data is obtained by conducting four-roll flexible rolling forming on LY12 aluminum alloy experimental material. A numerical model is then established using finite element analysis to simulate key parameters such as stress, deformation, and temperature distribution during the forming process. Adjustments to process parameters are made based on the analysis of numerical simulation results to achieve optimized forming. Additionally, the uniformity of four-roll flexible rolling forming of LY12 aluminum alloy with different hardness and thickness is examined. The research findings reveal that optimizing process parameters leads to a 14.95 % improvement in forming accuracy and a 30.52 % reduction in residual stress for LY12 aluminum alloy sheets, significantly enhancing product quality and efficiency. This study not only deepens the understanding of the four-roll flexible rolling forming process but also provides a feasible optimization parameter scheme. The results offer specific guidance for the application of lightweight high-strength materials such as LY12 aluminum alloy in actual production, thereby providing important technical support for improving forming efficiency and quality.

Deformation prediction of overlying strata in multi-seam mining based on the influence function method-key stratum hybrid model

The extraction of coal seams from subterranean strata has the potential to induce displacement and deformation within the overlying strata. This leads to fractures in the strata and surface subsidence. The repetitive mining of coal seams, especially in scenarios involving multiple coal seams, can reactivate previously stabilized rock strata, causing them to subside and deform again. This exacerbates deformation and compromises the structural integrity of the strata. Consequently, there is an imperative need to thoroughly investigate the patterns of movement exhibited by overlying rock layers as a result of the recurrent extraction of coal seams. In recent years, significant progress in this field has been the effective utilization of the Influence Function Method-Key Stratum (IFM-KS) hybrid model. This model, distinguished by its amalgamation of mechanical and geometric methodologies, has proven to be efficacious in scrutinizing the movement dynamics of overlying strata in the context of single-layer mining operations. Based on that, this paper introduces a novel model for predicting rock layer movement and deformation in multi-seam mining. The calculation results derived from this model reveal the dynamics of rock layers' movement and deformation following secondary disturbances during repetitive mining. The accuracy and reliability of this newly proposed model in predicting rock movement during dual-layer coal mining are validated through both theoretical calculations and UDEC numerical simulations. The results demonstrate a high degree of consistency between the numerically simulated rock displacement and mathematical calculations and the rationality of the model. Based on the rock strata movement calculation results, the corresponding porosity distribution is also derived. Compared to single-layer coal mining, multi-seam mining could cause greater changes in porosity in the goaf area and extensive damage to rock strata. More fracture pathways between coal seams occur and a volume of air-leakage quantity is expected. This computational model provides invaluable insights for predicting rock strata deformation and porosity distribution in repetitive mining scenarios of a similar nature.

The improved Moho depth imaging in the Arabia-Eurasia collision zone: A machine learning approach integrating seismic observations and satellite gravity data

The Arabia-Eurasia convergences created one of the earth's topographic highs on the Central Tethys collisional belt. Despite the area's geological significance, a comprehensive and high-resolution map of Moho depth has been lacking due to the sparse and uneven distribution of seismically constrained Moho depth data. This study addresses this deficiency by compiling an extensive dataset of nearly 2500 seismically measured Moho depth points from 68 seismic local scale studies, resulting in the development of an updated seismically constrained Moho depth model (S-Moho) at a 0.5° × 0.5° spatial resolution. Despite some coverage gaps in the remote areas, the S-Moho model offers a more detailed view than previously available. To further improve the coverage of the S-Moho depth model, an incremental data-driven approach was employed. Initially, a gravity-based regression Moho depth model (SB-Moho) was developed by correlating S-Moho depth points with corresponding Bouguer anomalies. However, its accuracy was constrained by unaccounted isostatic and non-isostatic components. To address this limitation, a sliding window approach was applied to derive a windowed SB-Moho model (WSB-Moho). Additionally, a machine learning-based Moho model (ML-Moho) was developed using seismic Moho depth points along with 11 predictive variables. Both WSB-Moho and ML-Moho models demonstrated consistent and smooth Moho depth variations. The Zagros region reveals a prominent NW-SE oriented Moho depression (45-60 km thick), attributed to the underthrusting of the Arabian Plate beneath the Iranian Plateau. The models suggest that crustal thickening extends beyond tectonic boundaries, likely influenced by the dip of suture zones. In contrast, the crustal thickening in eastern Anatolia, northwest of the Zagros, is less pronounced, indicating different geodynamic processes. Strike-slip faulting and magmatic activity in this area contribute to a broader distribution of deformation compared to the more localized crustal thickening in the Zagros. In southeastern Zagros, strike-slip faults in central Iran accommodate much of the northward convergence of the Arabian Plate, thereby limiting the extent of crustal thickening.

Mechanical Behaviour of 7075-T6 Aluminium Alloy: Integrating Digital Image Correlation and Finite Element Analysis for Uniaxial and Biaxial Load Scenarios

The objective of this study is to investigate the mechanical properties of 7075-T6 Aluminium (Al) alloy under both uniaxial and biaxial loads. The study will be conducted using a combination of experimental and numerical methods. The experimental method used is the digital image correlation (DIC) technique, which was utilized to capture the deformation and strain fields of the material specimen under tensile test. A tensile machine was employed to apply uniaxial and biaxial loads on the sample. The strain and deformation distribution of the results was generated on the DIC and correlated software. The numerical method involved the use of a commercial finite element software to create a finite element model and simulate the mechanical behaviour of the material under the same loading conditions. The results obtained from the experimental and numerical methods were compared to validate the accuracy of the numerical model. The outcomes demonstrated that under uniaxial loading, localized necking and fracture were observed, while biaxial loading resulted in shear deformation and fracture. This research contributes to the development of more accurate models for predicting the mechanical behaviour of the model samples under different loading conditions.

Investigation of the spatial distribution of deformations in quartz piezo elements by x-ray topography

Using X-ray topography on laboratory and synchrotron X-ray sources, the distribution of deformations in the volume of two types of AT-cut quartz resonators of different sizes were obtained. From a comparison of X-ray data and the amplitude-frequency characteristics of the resonators, a correlation between the deformation patterns and the features of oscillatory processes for operating modes and their harmonics, as well as for parasitic modes, was established. A connection between oscillations in parasitic modes, which manifest themselves in the amplitude inhomogeneity, and the topology of the resonators is found. The applied significance of the obtained results for the development and optimization of new designs of piezoelectric elements and the development of their manufacturing technology is noted.

Effect of welding layers and interlayer temperature on welding residual stress and deformation of Q345/316L dissimilar steel

Abstract Dissimilar steel welding is widely used in machinery, chemical industry, electric power and other fields. Due to the different welding materials, the distribution of residual stress and deformation of welded joints is complex. In order to study the influencing factors and variation rules of residual stress and deformation distribution of dissimilar steel joints, considering the nonlinear physical and mechanical properties of welding materials and the latent heat of phase change during welding, based on the SYSWELD platform, taking Q345 carbon steel and 316L stainless steel as the research objects, the double ellipsoid heat source model was used to study the effects of welding layers and interlayer temperature on the residual stress and deformation of joints. The results show that the increase of the number of welding layers is beneficial to expand the distribution of residual stress, and has no obvious effect on the residual stress of the weld, but it will reduce the residual stress of the base metal near the weld. However, the increase of the number of layers will also aggravate the deformation of the weld. Therefore, it is necessary to consider the design of the number of welding layers considering the thickness of the component. At the same time, the study also found that the interlayer temperature has a certain influence on the residual stress and deformation of the joint. The increase of the interlayer temperature will reduce the welding angle deformation, and has little effect on the transverse shrinkage and the residual stress of the joint. Therefore, a lower interlayer temperature should be selected for multi-layer and multi-pass welding of dissimilar steel to ensure the quality of the welded joint.

A multifunctional and tough lotus root starch-based bio-photonic hydrogel for stretchable fabric pattern color change and water rewriting.

Photonic crystal hydrogels (PCHs) are innovative materials that translate imperceptible deformations and humidity changes into visible colors, broadening the applications of photonics in bioengineering and smart materials. To overcome poor mechanical properties of traditional PCHs limited by weak intermolecular forces, we designed a PCH with a dual-network framework comprising N-isopropylacrylamide-co-acrylamide (NIPAM-co-AM) and biomass lotus root starch (LR). Since LR is rich in hydroxyl groups, it can undergo molecular linkage entanglement with the NIPAM-co-AM hydrogel matrix, forming hydrogen bonds that significantly enhance the mechanical properties of the PCH. We have prepared PCH films capable of conveying multidimensional information about the extent and distribution of transient deformation by encapsulating magnetic photonic crystal microspheres (MPCMs) within a hydrogel matrix. The PCH films were found to have ultrafast response time (< 10 s), full-color tunable range, high spatial resolution, excellent mechanical toughness (tensile up to 0.17 MPa) and sensitivity (2.52 nm %-1), and were able to sense relative humidity (RH) from 11 % to 98 %. Equipped with a dynamically reconfigurable lattice, this dual-responsive (tensile/humidity) PCH not only facilitates the creation of water-rewritable photonic films but also holds promise for integration into structural color elastic fabrics, thereby presenting novel prospects for smart textile applications.

Role of molecular damage in crack initiation mechanisms of tough elastomers

Tough soft materials such as multiple network elastomers (MNE) or filled elastomers are typically stretchable and include significant energy dissipation mechanisms that prevent or delay crack growth. Yet most studies and fracture models focus on steady-state propagation and damage is assumed to be decoupled from the local stress and strain fields near the crack tip. We report an in situ spatial-temporally resolved 3D measurement of molecular damage in mechanophore-labeled MNE just before a crack propagates. This technique, complemented by digital image correlation, allows us to compare the spatial distribution of both damage and deformation in single network (SN) elastomers and in MNE. Compared to SN, MNE have a wide-spread damage in front of the crack and, surprisingly, delocalize strain concentration. A continuum model, where damage distribution is fully coupled to the crack tip fields, is proposed to explain these results. Additional measurements of time-dependent molecular damage during fixed grips relaxation in the presence of a crack reveal that the less localized damage distribution delays fracture initiation. The observations and exploratory modeling reveal the dynamic fracture mechanism of MNE, providing guidance for rational design of high-performance tough elastomers.

Finite element analysis of 2.5D packaging processes based on multi-physics field coupling for predicting the reliability of IC components

The 2.5D packaging technology is a high–performance method for electronic packaging. This study addresses the reliability issues of 2.5D packaging during the manufacturing process. A multi–physics field coupling Finite Element Method (FEM) has been developed, combined with sub–modeling techniques, to investigate the curing of underfill adhesive, the curing of Epoxy Molding Compound (EMC), and the reflow soldering between the interposer and substrate in a 2.5D packaging entity during various manufacturing procedures. The focus is on the thermo–mechanical–chemical behavior of viscoelastic components within the packaging structure, as well as the viscoplastic characteristics of the micro solder balls and microbumps. A systematic analysis is conducted on the warpage deformation and stress distribution of the 2.5D packaging at crucial time points. The results demonstrate that after curing, the overall warpage of the packaging exhibits a ‘concave’ warpage profile. Additionally, as the thickness of the EMC above the chip increases, the warpage value of the packaging also increases. The warpage value defined by linear elasticity is larger than that defined by viscoelasticity. The maximum Von Mises stress value in the key areas of the submodel is greater than the maximum Von Mises stress value in the corresponding key areas of the global model. After reflow soldering, the stress concentration in the micro solder balls occurs at the edge of the micro solder ball array. The maximum stress values for each component of the packaging are observed in the interface areas between the components. Packaging components that undergo the curing process have notably higher warpage and Von Mises stress values than those that do not undergo the curing process. The simulation method established in this study can accurately predict the warpage deformation and stress distribution state of 2.5D packaging, providing significant engineering application value for process optimization and reliability enhancement of 2.5D packaging in the production process.

Theoretical analysis of the forming process of closed die forging with flash and optimization design method of flash gutter

The subject of this article is the forming process of closed die forging with flashes and the optimal design of the flash gutter dimensions. The goal is to conduct an in-depth theoretical analysis of the forming process of closed die forging with flash and to research the optimal design of the flash gutter dimension, aiming to improve the scientificity and efficiency of the forging process, guide the optimization of process parameters in actual production, extend the service life of dies, reduce material waste, and enhance product quality and production efficiency. The tasks were to establish an accurate mathematical model for closed die forging with flash to analyze metal plastic deformation and stress distribution, to conduct in-depth research on key factors such as stress distribution, position of the neutral plane, and flash gutter design during the forming process, and to validate the mathematical model through finite element simulation using DEFORM-2D software. The methods used include theoretical analysis, mathematical modeling, and finite element simulation validation. The theoretical analysis provides a foundation for understanding the forming process and stress distribution, whereas the mathematical model allows for quantitative analysis. Validation of the finite element simulation provides a means to test and refine the theoretical analysis and mathematical model. The following results were obtained: the existing mathematical model underestimates the height of the main deformation zone, which results in an unreasonable flash gutter design. After verification and correction, the error in the optimized mathematical model did not exceed 10 %, and the flash amount was significantly reduced. Additionally, a stress analysis of difficult-to-fill cavity positions revealed that the entrance radius of the cavity significantly affects the final filling. Conclusions. The scientific novelty of the results obtained is as follows: A mathematical model of closed die forging with flash was established to analyze the metal plastic deformation and stress distribution, providing theoretical support for die design optimization, forging quality improvement, cost reduction, and productivity improvement. Using the Deform-2D finite element simulation, the optimal design criterion for the flash was refined, resulting in a substantial reduction in the flash amount and material savings.