Deformable 3D Research Articles

COMPARISON OF FORGING LOAD, MATERIAL FLOW AND PRESSURE DISTRIBUTION OF THE UNI-DIRECTIONAL, BI- DIRECTIONAL AND TWO-STEP FORGING PROCESSES

Because of high productivity, closer dimensional tolerances, and minimal material waste precision forging (net or near net shape) processes have been used for manufacturing automobile components. The primary disadvantage of precision forging is the encountered higher tool stresses due to applied higher forging loads. Thus, forging load reduction is a higher priority in precision forging in terms of energy consumption and cost because higher loads required higher investment and higher energy consumption. Forging load is affected by several parameters such as temperature, material flow, the geometry of the billet, and punch movement. In this study, forging load, material flow, and normal pressure distribution in the forged part were investigated considering uni-directional, bi-directional, and two-step forging processes. FEM simulations were performed by using a solid cylindrical billet. To perform FEM simulations, the finite element analysis package (DEFORM 2D) was used. Also, experimental studies of the FEM models were performed. For bi-directional and step-forging experimental studies, a double-acting servo press was used because the movement of the top and bottom punch can be controlled accurately. Then the results of FEM and experimental studies were compared with each other. The results of the FEM simulations and experimental studies show two-step forging offers lower forging load and energy consumption whereas the uni-directional closed die forging process needs higher load and energy consumption

Modular incorporation of deformable spine and 3D neck musculature into a simplified human body finite element model

Spinal injuries are a concern for automotive applications, requiring large parametric studies to understand spinal injury mechanisms under complex loading conditions. Finite element computational human body models (e.g. Global Human Body Models Consortium (GHBMC) models) can be used to identify spinal injury mechanisms. However, the existing GHBMC detailed models (with high computational time) or GHBMC simplified models (lacking vertebral fracture prediction capabilities) are not ideal for studying spinal injury mechanisms in large parametric studies. To overcome these limitations, a modular 50th percentile male simplified occupant model combining advantages of both the simplified and detailed models, M50-OS + DeformSpine, was developed by incorporating the deformable spine and 3D neck musculature from the detailed GHBMC model M50-O (v6.0) into the simplified GHBMC model M50-OS (v2.3). This new modular model was validated against post-mortem human subject test data in four rigid hub impactor tests and two frontal impact sled tests. The M50-OS + DeformSpine model showed good agreement with experimental test data with an average CORrelation and Analysis (CORA) score of 0.82 for the hub impact tests and 0.75 for the sled impact tests. CORA scores were statistically similar overall between the M50-OS + DeformSpine (0.79 ± 0.11), M50-OS (0.79 ± 0.11), and M50-O (0.82 ± 0.11) models (p > 0.05). This new model is computationally 6 times faster than the detailed M50-O model, with added spinal injury prediction capabilities over the simplified M50-OS model.

Evaluation of Powder Metallurgy Workpiece Prepared by Equal Channel Angular Rolling.

The aim of the article is to examine the workability of sintered powder material of aluminum alloy (Alumix 321) through severe plastic deformations under the conditions of the equal channel angular rolling (ECAR) process. Accordingly, the stress-strain analysis of the ECAR was carried out through a computer simulation using the finite element method (FEM) by Deform 3D software. Additionally, the formability of the ALUMIX 321 was investigated using the diametrical compression (DC) test, which was measured and analyzed by digital image correlation and finite element simulation. The relationship between failure mode and stress state in the ECAR process and the DC test was quantified using stress triaxiality and Lode angle parameter. It is concluded that the sintered powder material during the ECAR processing failure by a shearing fracture because in the fracture location the stress conditions were close to the pure shear (η and θ¯ ≈ 0). Moreover, the DC test revealed the potential role as the method of calibration of the fracture locus for stress conditions between the pure shear and the axial symmetry compression.

An integrated approach of FEM analysis using DEFORM 3D and experimental investigation of forces developed in Al-Si7Mg

An integrated approach of FEM analysis using DEFORM 3D and experimental investigation of forces developed in Al-Si7Mg

Simulation and analytical studies of chip formation processes in the cutting zone of titanium alloys

The low machinability of titanium alloys is determined by the physical, mechanical, and chemical properties of these materials and their mechanical characteristics. It is also evident in the hardened state of the material being processed during cutting, as well as in the initial state. This phenomenon is caused by thermodynamic parameters that determine the properties of titanium material at elevated temperatures. The peculiarities of the cutting and chip formation processes during titanium alloy machining are presented in this article. The peculiarity of the described approach is the analysis of the results of simulation modeling of cutting in Deform 2D software. It is proved that the frictional factor in the formation of the thermal characteristics of the cutting process, which arises as a result of the chip sliding along the tool, dominates the load factor (caused by force and deformation processes in the chip root). It has been established that the length of contact between the chips and the tool’s rake face has a certain tendency to change: the contact length first increases and then decreases with increasing cutting speed. An analysis of the dependence of the chip compression ratio on changes in cutting speed has shown that with an increase in cutting speed, the average value of the compression ratio practically does not change, but the amplitude of its oscillation increases significantly, which is equivalent to a change in the shear angle. This parameter changes dynamically due to the adiabatic nature of chip formation

Investigation of the Technological Possibility of Manufacturing Volumetric Shaped Ductile Cast Iron Products in Open Dies

Information about the technological possibility of stamping in open dies, round-shaped forgings made of ductile cast iron, is outlined herein. Cast iron's propensity for plastic deformation under complex loading conditions is analyzed from the standpoint of the morphology of graphite inclusions, depending on the degree and mechanical scheme of deformation. The research methodology included: the choice of a brand of cast iron with spherical graphite and the technological process of its deformation; mathematical modeling of the deformation process using the DEFORM-3D software package; stamping of an experimental batch of forgings; and microstructural studies of the forging material, together with the data of its stress-strain state and the direction of flow of the material. Under the conditions of comprehensive compression of the workpiece material at the beginning of the deformation process, lateral pressure was created from the tool walls. It was carried out by selecting the size and shape of the initial blank by mathematical modeling. When analyzing the morphology of graphite inclusions, the stress state scheme was determined as the main influencing factor. The greatest change in the shape and size of graphite inclusions of cast iron, including their crushing, corresponds to the condition of the disappearance of all-round compression. When stamping in open dies, this occurs in the area where the material exits from the stamp engraving into the flash gutter. In the process of forming, cast iron showed the possibility of deformation in the deformation intensity index εi = 2.5.

Some Slippage Issues in High-Pressure Torsion Using Cu and Ti Samples as an Example

The effect of slippage during High Pressure Torsion (HPT) of technically pure Ti and pure Cu samples was investigated. The "joint torsion of the disk halves" method was used to evaluate the effect of slippage. It was shown that slippage starts already at the early stages of HPT. With a further increase in the number of revolutions n, the slippage effect increases, and no torsional deformation occurs after n = 5. The slippage effect is explained by analyzing the surface friction forces between the sample and the anvil. However, studies via TEM and XRD have shown that the structure of Ti samples after HPT at the investigated conditions is grinded to a nanocrystalline state. A structure is formed in Ti similar to that observed after HPT by other authors. The dislocation density increases with increasing HPT degree from n = 5 to n = 10 revolutions, despite slippage. Consequently, despite slippage at HPT at n ≥ 5, deformation still occurs. The following assumptions are made to explain the accumulated strain in the sample at HPT. It is assumed that the planes of the upper and lower anvil during HPT are at a slight inclination relative to each other. Computer modeling using the Deform 3D software package has shown that this leads to the accumulations of significant strain during HPT.

A Mortar Finite Element Formulation for Large Deformation Lubricated Contact Problems with Smooth Transition Between Mixed, Elasto-Hydrodynamic and Full Hydrodynamic Lubrication

This work proposes a novel model and numerical formulation for lubricated contact problems describing the mutual interaction between two deformable 3D solid bodies and an interposed fluid film. The solid bodies are consistently described based on nonlinear continuum mechanics allowing for finite deformations and arbitrary constitutive laws. The fluid film is modelled as a quasi-2D flow problem governed by the (thickness-)averaged Reynolds equation. In contrast to existing approaches, the proposed model accounts for the co-existence of frictional contact tractions and hydrodynamic fluid tractions at every local point on the contact surface of the interacting bodies and covers the entire range of lubrication in one unified modelling framework with smooth transition between these different regimes. From a physical point of view, this approach can be considered as a model for the elastic deformation of asperities on the lubricated contact surfaces. The finite element method is applied for spatial discretization of the 3D solid-mechanical problems and the 2D interface effects, consisting of the averaged Reynolds equation governing the fluid film and the non-penetration constraint of the mechanical contact problem. A consistent and accurate model behavior is demonstrated by studying several challenging benchmark test cases.

A soft microrobot with highly deformable 3D actuators for climbing and transitioning complex surfaces.

The climbing microrobots have attracted growing attention due to their promising applications in exploration and monitoring of complex, unstructured environments. Soft climbing microrobots based on muscle-like actuators could offer excellent flexibility, adaptability, and mechanical robustness. Despite the remarkable progress in this area, the development of soft microrobots capable of climbing on flat/curved surfaces and transitioning between two different surfaces remains elusive, especially in open spaces. In this study, we address these challenges by developing voltage-driven soft small-scale actuators with customized 3D configurations and active stiffness adjusting. Combination of programmed strain distributions in liquid crystal elastomers (LCEs) and buckling-driven 3D assembly, guided by mechanics modeling, allows for voltage-driven, complex 3D-to-3D shape morphing (bending angle > 200°) at millimeter scales (from 1 to 10 mm), which is unachievable previously. These soft actuators enable development of morphable electroadhesive footpads that can conform to different curved surfaces and stiffness-variable smart joints that allow different locomotion gaits in a single microrobot. By integrating such morphable footpads and smart joints with a deformable body, we report a multigait, soft microrobot (length from 6 to 90 mm, and mass from 0.2 to 3 g) capable of climbing on surfaces with diverse shapes (e.g., flat plane, cylinder, wavy surface, wedge-shaped groove, and sphere) and transitioning between two distinct surfaces. We demonstrate that the microrobot could navigate from one surface to another, recording two corresponding ceilings when carrying an integrated microcamera. The developed soft microrobot can also flip over a barrier, survive extreme compression, and climb bamboo and leaf.

Dose perturbations in proton pencil beam delivery investigated by dynamically deforming silicone-based radiochromic dosimeters

Objective. Proton therapy with pencil beam delivery enables dose distributions that conform tightly to the shape of a target. However, proton therapy dose delivery is sensitive to motion and deformation, which especially occur in the abdominal and thoracic regions. In this study, the dose perturbation caused by dynamic motion with and without gating during proton pencil beam deliveries were investigated using deformable three-dimensional (3D) silicone-based radiochromic dosimeters. Approach. A spread-out Bragg peak formed by four proton spots with different energies was delivered to two dosimeter batches. All dosimeters were cylindrical with a 50 mm diameter and length. The dosimeters were irradiated stationary while uncompressed and during dynamic compression by sinusoidal motion with peak-to-peak amplitudes of 20 mm in one end of the dosimeter and 10 mm in the other end. Motion experiments were made without gating and with gating near the uncompressed position. The entire experiment was video recorded and simulated in a Monte Carlo (MC) program. Main results. The 2%/2 mm gamma index analysis between the dose measurements and the MC dose simulations had pass rates of 86%–94% (first batch) and 98%–99% (second batch). Compared to the static delivery, the dose delivered during motion had gamma pass rates of 99%–100% when employing gating and 68%–87% without gating in the experiments whereas for the MC simulations it was 100% with gating and 66%–82% without gating. Significance. This study demonstrated the ability of using deformable 3D dosimeters to measure dose perturbations in proton pencil beam deliveries caused by dynamic motion and deformation.

Deep Shape-from-Template: Single-image quasi-isometric deformable registration and reconstruction

Shape-from-Template (SfT) solves 3D vision from a single image and a deformable 3D object model, called a template. Concretely, SfT computes registration (the correspondence between the template and the image) and reconstruction (the depth in camera frame). It constrains the object deformation to quasi-isometry. Real-time and automatic SfT represents an open problem for complex objects and imaging conditions. We present four contributions to address core unmet challenges to realise SfT with a Deep Neural Network (DNN). First, we propose a novel DNN called DeepSfT, which encodes the template in its weights and hence copes with highly complex templates. Second, we propose a semi-supervised training procedure to exploit real data. This is a practical solution to overcome the render gap that occurs when training only with simulated data. Third, we propose a geometry adaptation module to deal with different cameras at training and inference. Fourth, we combine statistical learning with physics-based reasoning. DeepSfT runs automatically and in real-time and we show with numerous experiments and an ablation study that it consistently achieves a lower 3D error than previous work. It outperforms in generalisation and achieves great performance in terms of reconstruction and registration error with wide-baseline, occlusions, illumination changes, weak texture and blur. • DeepSfT is a DNN fully-convolutional based on residual encoder-decoder for SfT. • We propose a semi-supervised end-to-end training procedure with synthetic and real data. • DeepSfT is a solution to cope with multiple imaging geometries, at training and inference. • We propose to combine DeepSfT with a physics-based estimation procedure.

Simulation of rolling of continuously cast billets in a breakdown stand for production of an I-beam 100Sh

As part of the expansion of the sphere of industrial and civil construction, it was proposed to master the production of large-sized I-beams 80–90–100, with the inclusion of their configurations in GOST R 57837–2017. Under the conditions of the Central PSB of EVRAZ NTMK JSC, a technology and calibration of rolls was developed to obtain all standard sizes of I-beams of this nomenclature range from one standard size of CW 1050x450x120. The purpose of this study is to check the possibility of obtaining from this section of the continuous casting machine the required dimensions of rolls from the breakdown stand 1300 for further rolling of the beams on the UBS, according to the existing technology. On the example of obtaining a rolled product for the production of I-beams 100Sh, the rolling process in the stand 1300 was simulated using the Deform 3D program. Modeling consisted in sequential reverse rolling of six passes with two turnings in the first closed pass, and the seventh (finishing pass) in the second open pass. The simulation results showed that under the conditions of the Central PSB of EVRAZ NTMK JSC, it is possible to produce an I-beam 100Sh from a continuous casting machine. The nature of stress changes from the first to the last passes is shown. As a result of modeling, it was revealed that the lack of guide rulers to hold the billet led to the displacement of part of the metal into one shelf and the rolling asymmetry. The maximum values of the torque appear in the finishing pass, while there remains a three-fold margin for the moment of the stand 1300, which indicates the possibility of obtaining a billet for the universal beam mill intended for rolling the I-beam 100Sh. In the future, to test the use of the original CLM with the proposed cross-sectional dimensions, it is also necessary to simulate the rolling of I-beams 80, 90 to obtain the original billet on the universal beam mill.

Corrugation prediction in process of sheet drawing based on the results of modeling in the DEFORM environment

In a process of sheet drawing technology developing, the probability of workpiece buckling during deformation and the necessity of blank holder using to prevent corrugation, is estimated in accordance with the recommendations of the reference book. However, reference literature does not have clear recommendations, or it gives contradictory recommendations for blank holder use cases for some deformation conditions. In these cases, problem solving requires additional experimental research. Possibility and efficiency establishing of computer simulation using DEFORM environment of axisymmetric drawing processes to forecast the buckling of a thin-sheet workpiece during deformation. Technological processes of sheet drawing with a high probability of workpiece buckling were investigated by means of finite element computer simulation in DEFORM 3D. Research has established that simulation of thin-sheet workpiece drawing process in DEFORM 3D, allows to visualize the process of corrugation, and predict workpiece buckling with high probability, provided that the deformation occurs relatively simple geometry of the workpiece and deforming tool. In more complex deformation conditions, the experiments results, and computer simulation may differ (simulations may not indicate corrugation). This somewhat complicates corrugation prediction, but the problem is solved by an extended analysis of the stress-strain state and workpiece behavior in the deformation zone. The emergence of areas in the workpiece with an unpredictable and uncontrolled contact loss of the workpiece material with the deforming tool, or appearance of areas with significant irregular velocity of workpiece points movement, clearly indicates problem areas with high probability of corrugation in the real sheet drawing process. Obtained results allow to increase the efficiency of expecting places of corrugation appearance prediction by means of computer simulation of sheet drawing process in the DEFORM 3D environment.

Robust Isometric Non-Rigid Structure-From-Motion.

Non-Rigid Structure-from-Motion (NRSfM) reconstructs a deformable 3D object from keypoint correspondences established between monocular 2D images. Current NRSfM methods lack statistical robustness, which is the ability to cope with correspondence errors. This prevents one to use automatically established correspondences, which are prone to errors, thereby strongly limiting the scope of NRSfM. We propose a three-step automatic pipeline to solve NRSfM robustly by exploiting isometry. Step (i) computes the optical flow from correspondences, step (ii) reconstructs each 3D point's normal vector using multiple reference images and integrates them to form surfaces with the best reference and step (iii) rejects the 3D points that break isometry in their local neighborhood. Importantly, each step is designed to discard or flag erroneous correspondences. Our contributions include the robustification of optical flow by warp estimation, new fast analytic solutions to local normal reconstruction and their robustification, and a new scale-independent measure of 3D local isometric coherence. Experimental results show that our robust NRSfM method consistently outperforms existing methods on both synthetic and real datasets.

Learning Dynamic 3D Geometry and Texture for Video Face Swapping

AbstractFace swapping is the process of applying a source actor's appearance to a target actor's performance in a video. This is a challenging visual effect that has seen increasing demand in film and television production. Recent work has shown that data‐driven methods based on deep learning can produce compelling effects at production quality in a fraction of the time required for a traditional 3D pipeline. However, the dominant approach operates only on 2D imagery without reference to the underlying facial geometry or texture, resulting in poor generalization under novel viewpoints and little artistic control. Methods that do incorporate geometry rely on pre‐learned facial priors that do not adapt well to particular geometric features of the source and target faces. We approach the problem of face swapping from the perspective of learning simultaneous convolutional facial autoencoders for the source and target identities, using a shared encoder network with identity‐specific decoders. The key novelty in our approach is that each decoder first lifts the latent code into a 3D representation, comprising a dynamic face texture and a deformable 3D face shape, before projecting this 3D face back onto the input image using a differentiable renderer. The coupled autoencoders are trained only on videos of the source and target identities, without requiring 3D supervision. By leveraging the learned 3D geometry and texture, our method achieves face swapping with higher quality than when using off‐the‐shelf monocular 3D face reconstruction, and overall lower FID score than state‐of‐the‐art 2D methods. Furthermore, our 3D representation allows for efficient artistic control over the result, which can be hard to achieve with existing 2D approaches.

Study of Temperature Distribution in the Tool Blank Contact at Different Thermal Friction Milling Methods

As a result of the research of the factory technology for the restoration of parts of the rolling stock coupling device in the conditions of "Electric locomotives assembly factory" LLP (Nur-Sultan, Kazakhstan), it is revealed that it is not always possible to maintain the original hardness of the cladding material after cladding or machining. In order to solve this issue, the authors propose methods of thermal friction machining, traditional thermal friction milling and thermal friction milling with pulse cooling. In this paper, the results of temperature distribution in the "tool-workpiece" contact in different methods of thermal friction milling are presented. Scientific and practical interest is the temperature during the deep machining the workpiece. This is because the hardness of the surface treated by thermal friction milling can be assessed by its result. The process has been simulated using the Machining module of the Deform 3D software package. As a result, the depth of the temperature distribution deep into the workpiece and the temperature values in the cutting zone have been established.

Effect of Titanium Based Alloys on Thermo-Mechanical Behavior in 3D Forging Simulation

Titanium has been one of the traditional metals used in the medical industry since 1940. This work modeled and simulated a hip-joint replacement implant using Creo 5.0 and DEFORM 3D (v11.0), respectively. Four titanium-based billets were modeled; out of four billets, three billets were coated with a specified thickness, and one was uncoated. Among the three coated billets, one billet was coated with a 500-micron and two billets coated with a 1000-micron thickness. At the end of the simulation, the coating materials formed patches on the surface of the forged parts. The coating material Ti-6Al-4V (high O2) produced excellent mechanical properties in contrast to the CP-Ti material, which displayed low mechanical properties and did not match the core property. Hence, it was suggested to provide a bulk coating of Ti-6Al-4V (high O2) on the billet to improve the physio-mechanical properties and biocompatibility. Four points were selected on the surface of the forged parts at different locations for identifying the property variations concerning forging time. Results found that coating thickness required more on the side surface of the billet material than on the upper and lower surfaces to enhance its properties.

Experimental Study and Finite Element Analysis of Temperature Reduction and Distribution During Machining of Al-Si-Mg Composite Using Deform 3D

Composite materials are promising materials in the manufacturing industry due to the quality of their materials. However, in transforming these materials, the machining process experiences a high-heat generation rate, which has led to the study of temperature distribution, and reduction analysis at the cutting region. High-temperature generation during machining operation leads to thermal deformation on the developed component or parts, affecting the operation life span of the component. Thus, this study investigated the effect of mineral oil-based-Multi-walled carbon nanofluid (MWCNTs) compared to pure mineral oil in the turning of aluminum-silicon magnesium metal composite (AlSiMg) on temperature reduction and distribution. The nanofluid was prepared with 0.4g of MWCNT to 1 liter of mineral oil. The study employed the energy dispersive spectrometer to obtain the chemical composition of the developed nanofluid. Furthermore, Finite element software DEFORM 3D v11.0 uses a lagrangian incremental approach to simulate chip formation and temperature distribution on the workpiece. Also, to study the effects of the machining parameters on the temperature distribution. The experiment results showed a significant reduction of 11.9% in temperature when machining with nanofluid compared to pure mineral oil. The simulation results showed that the temperature increases as the cutting speed and feed rate increase. The minimum temperature via the DEFORM 3D Finite Element Model simulation was achieved at spindle speed 870 rpm, feed rate 2 mm/rev, and depth-of-cut 1 mm. In conclusion, the study recommends that the manufacturing industry employ the optimized machining parameters during the turning of AlSiMg metal matrix composite for a sustainable machining process.

EVALUATION OF SURFACE ROUGHNESS IN DRILLING OF AA 7075 T6 PLATE WITH DIFFERENT CUTTING TOOL GEOMETRIES WITH EXPERIMENTAL, STATISTICAL AND DEFORM 3D SIMULATION

The basis of the study is to examine the average surface roughness (Ra) value resulting from drilling AA 7075 T6 plates with drills with different point angles () and under different cutting parameters. However, two different point angles (118° and 135°), three different cutting speeds (Vc) (40, 60 and 80 m/min) and three different feeds (f) (0.04, 0.08 and 0.12 mm/rev) were preferred in the experiments. The effect of cutting and tool geometry parameters on Ra was digitized by performing an ANOVA analysis. It was determined that Ra increased with the increase of Vc,  and f. The parameter with the most significant effect on Ra was Vc with 49.10%, followed by  with 30.52% and f with 13.67%, respectively. In order to examine the reasons for the increase in Ra value more effectively, drilling simulations were carried out under different cutting parameters using Deform 3D software. The simulation estimated temperature, cutting force and damage during drilling. The predicted results and the factors on Ra were revealed. In the experiments carried out with the drill with a tip angle of 135°, it was estimated that the temperature, the temperature, the cutting force and the damage value along the Z-axis were higher than the drill with a tip angle of 118°.

Surface crack analysis of the steering shaft gear after carburizing and quenching

The phenomenon of surface cracks in steering shaft gear after carburizing and quenching was analyzed by combining experimental research, theoretical analysis, and numerical simulation. The chemical composition, crack morphology, non-metallic inclusions, microstructure, microhardness, and forging process were analyzed and studied by means of directly reading spectrometer, metallographic microscope, scanning electron microscope, energy dispersive spectrometer, and micro hardness tester. The evolution process of surface crack morphology was numerically simulated and reproduced with the help of Deform 3D point tracking technology. The results show that linear surface cracks are formed on the surface of the round steel because of Alumina-type non-metallic inclusions, which destroy the continuity of the steel matrix during the rolling process. Surface cracks become arc-shaped due to the regular plastic flow direction of the material and propagate in the depth direction during the forging process. Crack provide a channel for the diffusion of C atoms during carburizing and quenching process, therefore carburized layer with gradient distribution is formed on both sides of the crack. The carburized layer reacts with oxygen during quenching and subsequent tempering, resulting in a certain degree of oxidation on both sides of the crack and the crack tail. Therefore, the surface cracks found in the steering shaft gear after carburizing and quenching are originated from the rolling cracks formed by non-metallic inclusions of steel. The rolling cracks have undergone further evolution in the subsequent forging and carburizing quenching process.