Concave Deformation Research Articles

Study on the self-vibration characteristics of non-circular arches with cracks based on the transfer matrix method

As the span of reinforced concrete arch bridges continues to increase, so does the difficulty of construction. The structure is at risk of cracking. Most of the bridges under construction are non-circular arches, and there are few studies on such arches. The current study tried to investigate the self-vibration characteristics of non-circular arches with existing cracks. A computational approach proposed in the original non-circular arch is substituted with multiple infinitesimal arch segments having different radii of curvature, enabling the determination of natural frequencies and mode shapes of the non-circular arches with cracks. Furthermore, a finite element model (FEM) of the reinforced concrete structure with existing cracks is developed to assess the effects of various factors, including axial location, crack depth, and positions within the same cross-section. The results demonstrate the feasibility of the computational method using multiple infinitesimal arc segments with varied radii of curvature, yielding a maximum error of only 1.58 %, which satisfies engineering application standards. An increase in crack depth leads to a reduction in the natural frequencies of specific modes of the structure, while the effect on others is insignificant. For cracks situated at the top or bottom plates within the same cross-section, the impact differs based on the local deformation being convex or concave. If the deformation is convex, the top plate cracks exhibit a higher rate of change in natural frequencies compared to the bottom plate cracks; conversely, with concave deformation, the bottom plate cracks have a greater influence than the top plate cracks.

Study on hysteresis performance of corroded CHS T-joints under in-plane bending load

This research aims to examine the hysteresis behavior of corroded circular hollow section (CHS) T-joints when subjected to cyclic bending loading. Quasi-static tests including the coupling of brace axial load and in-plane cyclic moment were conducted on corroded CHS T-joint specimens to analyze the effects of corrosion damage on the hysteresis curve, failure mechanism, carrying capacity, and energy dissipation of the joints. Experimental results indicated the corrosion damage located at the different regions of joints had varying effects on the hysteresis behaviors of CHS T-joints. 1) The brace corrosion degree was more severe than the chord corrosion degree under the same exposure condition, however, the chord corrosion had a more significant influence on reducing the stiffness and ultimate carrying capacity of CHS T-joints. The ultimate capacity of CHS T-joints was found to decline by more than 20 % when the equivalent thickness loss of the chord was about 9.2 %. 2) Compared with chord corrosion, the brace corrosion would relieve the concave deformation and local plastic deformation of the chord so that more plastic cyclic damage concentrated around the intersection line. As a result, the through cracks prematurely occurred from the crown points on both sides, and the energy dissipation of CHS T-joints declined by more than 25 % when the equivalent thickness loss of the brace was about 13 %. The presence of axial loading on the brace not only affects the symmetry of hysteresis curves in CHS T-joints with non-uniform corrosion, but also exacerbates the concave deformation of the chord in chord corroded joints during the failure stage, thereby affecting the shape of hysteresis loops and fracture behavior of CHS T-joints when subjected to in-plane cyclic bending load.

Comprehensive Analysis of Laser Peening Forming Effects on 5083 Aluminum Alloy.

In order to investigate the laws of the laser peening forming process and the effects of laser peening on the surface quality and tensile properties of 5083 aluminum alloy, experiments were conducted utilizing various laser peening paths, energies, and plate thicknesses. Subsequently, laser peening forming experiments were performed on S-shaped and different shapes of aluminum alloy substrates. The impact of different laser peening durations on surface morphology and tensile properties was then analyzed. Results indicated that the largest bending deformation perpendicular to the laser peening path reached 12.5 mm. In cases where the laser peening path was inclined relative to the horizontal direction, torsional deformations were observed in the aluminum alloy plate. For laser energy levels of 5 J, 6 J, and 7 J, deformation amounts were 3.8 mm, 4.9 mm, and 5.4 mm, respectively. Plates with thicknesses of 4 mm exhibited convex deformation, while those with 2 mm thickness showed concave deformation. Furthermore, following one and two laser peening cycles, the residual stresses in the alloy plates were -80 MPa and -107 MPa, the surface hardness increased by 16 HV and 31 HV, the roughness increased by 2.495 μm and 3.615 μm, and the tensile strength increased by 9.5 MPa and 18.5 MPa, respectively.

Numerical investigation of unsteady shedding behaviors of a reentrant jet supercavity

To investigate the unsteady shedding characteristics of a reentrant jet supercavity with a low Froude number, a high-fidelity numerical model based on the inhomogeneous multiphase model is developed to predict the complex supercavitation flow that occurs during supercavity development. The developed solver is validated quantitatively against experimental results in terms of supercavity geometry and closure mode. This study focuses on the initial generation and development process of a reentrant jet supercavity, revealing three distinct stages: foam cavity, transparent supercavity with rapid growth in dimensions, and fully developed supercavity exhibiting significant deformation. Owing to reverse flow of the gas–water mixture, interfacial instabilities arise from the unsteady cavity shedding, leading to fluctuations in supercavity shape. The types of large-scale cavity shedding observed in this work—wing-like and cloud-like—are caused by the concave deformation resulting from the reentrant jet. As the gas entrainment coefficient increases, the unsteady characteristics of pressure oscillation weaken, and the instance of wing-like cavities decreases. When the gas entrainment coefficient reaches a critical value, the twin-vortex closure mode occurs, resulting in a more stable flow behavior. In sum, we propose a theoretical model that elucidates the strength of the reentrant jet and reveals its unsteady shedding behavior during supercavity development.

Effect of bending deformation on suspended topological insulator nanowires: Towards a topological insulator based NEM switch

Nanodevices consisting of the suspended and supported parts of topological insulator Bi2Se3 nanowires were fabricated and measured at low and room temperatures. Probing of topological surface states, accompanied by the electrostatic field effect used to dynamically manipulate bending deformation, was carried out to monitor the external strain introduced into the suspended and supported parts within the same Bi2Se3 nanowire. Depending on the device geometry, pure elastic and elastoplastic types of concave deformation, as well as convex buckling deformation, were realized in the suspended parts of the nanowires. For various types of observed deformations, different magnitudes of increase in the Source-Drain resistance of the deformed part compared to the relaxed part of the same devices were determined. All suspended devices exhibit external strain-sensitive Shubnikov-de Haas oscillation frequencies representing the carriers of top and bottom surface states and bulk, whereas, in the case of supported devices, the bottom surface states are masked by a trivial 2DEG. The obtained results may be useful for strain engineering of TI materials, as well as for applications in NEMS and other areas related to suspended nanostructures.

Structure and electrical properties of bilayer zigzag silicene nanoribbons depending on stone-wales and applied electric fields by SCC-DFTB method

The influence of geometry and electrical properties of Stone-Wales (SW) defects and an applied electric field on bilayer zigzag silicene nanoribbons (ZSiNRs) were investigated using the self-consistent charge density functional tight-binding (SCC-DFTB) method. The results show that concave deformation occurs at SW defects, leading to varying degrees of disruption in the original symmetrical structure. The overall stability of the marginal Stone-Wales (MSW) nanoribbons surpasses that of the central Stone-Wales (CSW) nanoribbons, SW-II type defects are prone to form in bilayer nanoribbons. The band gap of MSW defective nanoribbons expands significantly, realizing the transition from metallic to semi-metallic and semi-conductor properties. The electrons are transferred from the inner to the outer side of the nanoribbons, with a higher prevalence of defect nanoribbons compared to those that are perfect. The electric field intensity significantly alters the properties of both MSW-I and MSW-II defective nanoribbons.

Damage Characteristics and Dynamic Response of RC Shells Subjected to Underwater Shock Wave

Underwater bottom-sitting shell structures face threats from underwater explosion shock waves. To investigate the damage characteristics and dynamic response of bottom-sitting shell structures under underwater explosion shock waves, three-dimensional numerical models of semi-spherical and semi-cylindrical bottom-sitting reinforced concrete (RC) shells under underwater shock waves were established based on the Arbitrary Lagrangian–Eulerian (ALE) algorithm using LS-DYNA software. The influences of the shock wave transmission medium, explosive equivalent, explosive distance, hydrostatic pressure, and reinforcement on the damage characteristics and dynamic response of semi-spherical and semi-cylindrical bottom-sitting RC shell structures were studied. The results indicated that the damage and center vertical deformation of RC shells under underwater shock waves are significantly greater than those under air shock waves. With an increase in explosive equivalent or decrease in explosive distance, the damage and center vertical deformation of RC shells are increased. The damage to the inner surface of RC shells is more severe than the outer surface. The damage and center vertical deformation of RC shells can be reduced by bottom reinforcement and an increase in the diameter of the steel bar. The ‘hoop effect’ caused by hydrostatic pressure restrains the horizontal convex deformation and slightly decreases the macroscopic damage and vertical center deformation of the semi-spherical RC shell with an increase in hydrostatic pressure within the range of 0–2.0092 MPa. The hydrostatic pressure restrains the horizontal convex deformation of the semi-cylindrical RC shell. However, inward concave deformation of the shell center is increased by hydrostatic pressure, inducing an increase in the damage to and center vertical deformation of the semi-cylindrical RC shell. These findings may offer a reference for the construction and design of protective measures for underwater bottom-sitting shell structures.

In-situ consolidation deformation of composite laminate with gaps of various widths

Gaps between prepreg tapes, which occur when prepreg tapes are placed automatically, cause concave deformation of the laminate during consolidation, which degrades the quality of the cured laminate. However, this in-situ concave deformation has never been measured. This study measures consolidation deformation of a cross-ply thermosetting composite laminate containing gaps of various widths at the middle layer. A unique fiber-optic-based shape sensor is used for the in-situ deformation monitoring and the deformation during autoclave pressurization and heating is presented. The results indicate that the deformation phenomenon depends on whether the upper bagging-side layer bridging the gap contacts the tool-side layer below the gap as it sinks into the gap during consolidation. The consolidation process reveals when the gap width is narrow, the fibers and the resin from the prepreg layer flow into the gap and displace upwards the sunken upper layer, partially reducing the concave deformation. One attempt to suppress gap-induced deformation is also made by using a curing condition inspired by the observation and understanding of this deformation mechanism.

Spatial gas effect on the deformation behavior of embossed glass microstructures in hot embossing

Glass hot embossing is a well-established and cost-effective manufacturing method for glass microstructures. However, the spatial volume affects deformation behaviors in closed mold cavities, which determines the final shape of the embossed glass. To investigate the spatial gas effect on the glass deformation mechanism during hot embossing, we used the focused ion beam (FIB) to fabricate blind micro-hole array structures with different depths as embossing templates. The experimental results demonstrated that the spatial volume of the mold cavity has a great influence on the energy of gas expansion, thus affecting the deformation height of glass microstructures during hot embossing. The deeper the cavity depth, the bigger the surface tension, resulting in larger surface concave deformation. Due to the surface tension of gas expansion, the deformation height of the edge zone is higher than that of the center zone at a higher embossing temperature until the heated glass is completely compressed into the mold cavity. Additionally, at lower embossing temperatures (520 °C), the heated glass has a large deformation resistance and elastic recovery. The more deformation volume escape from the shallower mold cavity because of the spatial effect, thus the deformation height decreases as the cavity depth reduces. The work provides a better understanding of manufacturing glass microstructures in hot embossing.

Cube-corner retroreflectors for acoustic support outdoors: A comparison of simple and optimised designs

Activities conducted outdoors have reduced risk of disease transmission and yield positive mental and physical effects, but outdoor environments commonly suffer from acoustic problems such as urban noise, rapid spatial sound decay and insufficient acoustic support. This paper addresses the last problem, i.e., people's poor self-hearing due to lack of reflecting surfaces, which can reduce speaking comfort. The performance of easily fabricable, portable and deployable cube-corner retroreflectors (CCRs) is investigated through finite-difference time-domain (FDTD) acoustic simulations, omnidirectional measurements and oral-binaural measurements of physical prototypes. The CCRs' geometry is optimised to reduce sound dispersion using a process integrating parametric modelling, FDTD and genetic algorithms. Results show that optimisation can significantly boost the performance of CCRs by concave deformation of several centimetres, leading to more than doubling of the speech-weighted retroreflected energy of CCRs of 1 m edge lengths, and that of 0.5 m CCRs also substantially increased. Greatest improvements are achieved at high frequencies. Four CCRs of 0.5 m or one of 1 m, either simple or optimised, achieve speech-weighted voice support (STV) ranging from −19.1 to −15 dB over a 3 × 3 m area, better than common outdoor elements such as the ground or a wall and similar to typical enclosed rooms. CCRs are more effective for spectra emphasizing high frequencies, e.g., loud speech over normal speech, and larger CCRs have more balanced retroreflective spectra. This study provides a practical solution to improving weakly supported environments and thus contributes to improving the feasibility and acoustic quality of outdoor activities.

Calculating the ultimate strength of a tube–gusset KT joint with 1/4 ring stiffener plates

In this study, experiments, numerical simulations, and theoretical analyses were performed on tube–gusset KT joints with 1/4 ring stiffener plates, which are frequently used in electrical transmission line towers. The failure modes and mechanisms of the joint were determined to comprise either ‘chord failure’, in which the chord exhibits obvious deformation while the stiffener plate exhibits little deformation, or ‘stiffener plate failure’, in which the chord exhibits obvious concave deformation and the stiffener plate exhibits obvious warping deformation. An increase in chord axial compression caused the ultimate bearing capacity of the joint to decrease, though when the ratio of axial chord force to plastic limit was less than 0.2, this effect of was not obvious. Furthermore, an equation for the ultimate strength of a joint was proposed based on the conservation of energy, which was subsequently verified against test and finite element model results. In this equation, the influence of the chord axial compression on the bearing capacity of the joint is considered using the coefficient β, which is dependent on the ratio of the chord diameter to the chord thickness. Finally, the proposed bearing capacity calculation method was shown to reproduce the numerical analysis results more accurately than the Japanese code or CIDECT code. Thus, the proposed calculation method can be confidently used to guide joint design in electrical transmission line tower projects.

Mechanical properties of re-entrant anti-chiral auxetic metamaterial under the in-plane compression

Traditional auxetic metamaterials are characterized by negative Poisson’s ratio but weak stiffness. In this paper, a new auxetic metamaterial, re-entrant star-shape anti-chiral auxetic metamaterial (Re-S-AC), is proposed and the in-plane mechanical properties of the Re-S-AC are investigated by experimental test and numerical analysis. The crushing test of the Re-S-AC fabricated by the selective laser melting (SLM) method is performed to investigate the deformation mechanism and validate the accuracy of the numerical model. Compared with the anti-tetrachiral and re-entrant star-shape, the Re-S-AC simultaneously exhibits concave and rotational deformation under the in-plane compression, and mean compression stress is highest at the same thickness and same mass. In addition, parametric analysis is conducted to comprehensively reveal the influence of geometric characteristics on the mechanical properties of the Re-S-AC. The results found that the node center distance, node diameter and wall thickness have significant effect on the mechanical properties and deformation mode of the Re-S-AC. Compared with other parameters, wall thickness has the greater effect on the mechanical properties. When wall thickness is from 0.4 mm to 0.8 mm, the Young’s modulus, yield strength, and mean compression stress increase by 447.27%, 530.62%, and 370.87%, respectively. This study provides a reference method for improving the mechanical properties of the auxetic metamaterial.

Development of a Novel Biomimetic Mechanical Hand Based on Physical Characteristics of Apples

For the purpose of minimizing the damage to apples during the operation of an apple-picking robot, improving the stability of an apple-harvesting mechanical hand and reducing the use and operation cost of the robot, a novel biomimetic apple mechanical hand based on negative pressure air suction is purposely designed based on the physical characteristics of apples by imitating octopus predation. The mechanical hand has four suction cups evenly distributed in the hand, which produce concave deformation under negative vacuum pressure to fit the apple surface and adsorb the apple; the fruit stalk is separated by wrist rotation and dragging in a compound way to complete the picking operation. This paper firstly determines the key parameters of the mechanical hand based on the characteristics of silicone material and the three growth postures of apples, tries to make a physical prototype of the mechanical hand and conducts relevant performance tests on the picking platform built in the laboratory to explore the best combination of parameters and further optimize the manipulator. The results show that the success rate of the biomimetic nondestructive apple picker with the best combination of parameters is 100%, 76% and 68% for three different apple-growth postures and the operation is smooth, reliable, safe and non-invasive.

Varifocal Concave-Convex Lens Using Viscoelastic Gel and Ultrasound Vibration.

A varifocal concave-convex lens using ultrasound and transparent viscoelastic gel is reported. The configuration of the lens is simple and thin, consisting of four pieces of a piezoelectric ultrasound transducer, a glass disk, and a transparent silicone gel film. It uses a combination of the ultrasound resonant flexural standing- and traveling-wave modes excited by in-phase and four-phase drives so that the lens can change its shape to both concave and convex by switching the resonance mode with the same structure. The acoustic radiation force (ARF) originated from the resonant flexural vibration modes changed the surface profile of the gel. Convex and concave deformation were generated at the center of the lens at the resonance frequencies of 38 and 60 kHz, respectively, indicating that a varifocal concave-convex lens could be fabricated by controlling the driving frequency, voltage amplitude, and phase differences among the ultrasound transducers. The deformational displacement on the lens surface and the change in the focal length increased with the input voltage amplitude. The optical microscopic images observed through the lens were enlarged 1.28× (reduced 0.92× ) in the convex (concave) mode with 20 [Formula: see text]. The response time for focusing and the temperature stability under operation were evaluated. By switching the resonance vibration modes of the lens through the input signals to multiple ultrasound transducers, the variable-focus function with both concave and convex lenses was achieved in the same configuration.

Interfacial Flows and Interfacial Shape Modulation Controlled by the Thermal Action of Light Energy

The review covers the research on thermocapillary convection caused by the thermal action of laser radiation in single-layer and bilayer liquid systems of capillary thickness. The advantages of using optical radiation are the instantaneous delivery of thermal energy to a place on demand (a bulk phase, interfaces); low radiation power required; concentrating heat flux on a spot of a few micrometers; the production of arbitrary spatial distributions of radiation intensity; and, as a result, corresponding thermal fields at a liquid interface and their fast reconfiguration. Thermocapillary stresses at the liquid interfaces lead to the transfer of the liquid and a change in the shape of the interface, in accordance with the distribution of the light-induced thermal field. Studies concerned with the methods of non-destructive testing of liquid media and solids, which are based on a photothermocapillary signal emitted by a laser-induced concave deformation of a thin layer, are considered. Features of thermocapillary deformation of a liquid–air interface caused by local heating of thin and thick (exceeding the capillary length) layers are demonstrated. A part of the review addresses the results of the study of thermocapillary rupture of films in the heating zone and the application of this effect in semiconductor electronics and high-resolution lithography. The works on the light-induced thermocapillary effect in bilayer (multilayer) liquid systems are analyzed, including early works on image recording liquid layer systems, liquid IR transducers, and nonlinear optical media.

Study on arc characteristics of different defects in pulsed micro-plasma arc welding

The shape of welding arc is closely related to the quality of welding. For micro plasma arc welding (MPAW), however, the change of arc shape is not obvious enough to evaluate the quality of welding, due to the small size of welding arc. Thus, it needs to extract the specific features of arc shape through image processing algorithm to judge its change quantitatively. Furthermore, for workpiece with bright surface, it is difficult to extract the arc shape directly from the arc images because of the strong arc reflection on the workpiece surface. In this paper, a new method based on vertical Sobel operator was proposed to overcome the above-mentioned challenges, and to extract the clear arc shapes from the arc images of pulse micro plasma arc welding (P-MPAW). The arc length, arc width and the height difference between two sides of arc were extracted as characteristic parameters to reveal the influence of different welding defects on the arc shape. The changes of arc characteristic parameters have been studied in depth, when there are different defects such as burn through, misalignment, undercut, concave deformation, excessive gap and overlap. The results show that, excessive welding gap and misalignment, caused by the assembly and machining accuracy, have obvious characteristics in the instantaneous arc shape. The defects caused by welding thermal process like burn through, concave deformation, overlap and undercut have their own distinctive characteristics in the changing process of the arc shape.

Doom-roof steel tanks under external explosion: Dynamic responses and anti-explosion measures

Large-scale cylinder storage tank is a kind of typical thin shell space structure, which is widely used in the storage of petrochemical products such as LNG, LPG and so on. The dynamic responses and failure process for steel tank under external explosion shock wave are complex dynamic problems with strong instantaneity, strong non-linearity and strong coupling. In this paper, a coupled analysis model was developed for simulating the dynamic responses of tank under external ground explosion. Compared with experimental datas which were given in existing relevant studies, the validity for numerical model and accuracy for simulation results were verified. Dynamic response for typical cylindrical tank was obtained through coupled numerical simulation, and the influences of scaled distance and tank wall thickness were studied through parameter analysis. Based on the simplified model of explosion loading on tank, the difference of dynamic response between uncoupled model and coupled model was analyzed. The anti-explosion effect for different parameters of anti-explosion bands on tank under external explosion was finally compared. The results show that: 1) The lower two layers tank wall firstly appear inward concave deformation and local plastic state. With the shock wave propagating upward along tank wall, the concave deformation and plastic strain of the front surface of tank wall increase obviously, and the maximum deformation region moves up to the middle part of tank wall, while the maximum plastic region basically remains at the lower part of tank wall. 2) Both the changes of scaled distance and tank wall thickness have significant influences on the deformation and equivalent plastic strain for steel storage tank. The maximum equivalent plastic strain and fracture failure mode generally appears at the lower part of tank wall firstly. The increase of the tank wall thickness is an effective measure to reduce the deformation and plastic strain for tank, and strengthen the anti-explosion performance for tank. 3) Due to the obstacle effect of the anti-explosion bands, the maximum equivalent plastic strain region moves from the bottom part of tank wall to the middle and upper part of tank wall. The displacement and equivalent plastic strain for steel tank decrease with the increase of cross-section and spacing for anti-explosion bands, and the effect of the former (increase height only) is relatively better.

Modeling of Drying‐Induced Soil Curling Phenomenon

AbstractDrying‐induced soil curling is commonly observed in nature. In order to investigate the change of water distribution in soil caused by drying and curling, a series of drying tests is performed on thin soil layers in the laboratory. A discrete element model (DEM) is then proposed to simulate soil desiccation curling. The outermost particles are selected as the surface of the model to address the importance of surface evaporation. Moisture distribution change during drying is governed by both surface evaporation and moisture exchange between DEM particles. The results show that the model can capture the main features of the soil curling process from concave curling () to convex curling (). The model enables variation in moisture gradient during the drying process. The trend of the curling development obtained from the model agreed well with the laboratory observation. A newly exposed surfaces in the model can provide a more realistic moisture distribution and influence the curling behavior. Generally, the drying‐induced soil curling process and extent are associated with the change in moisture gradient along the depth. The movement of tensile stress concentration change from the upper layer in the early drying stage to the lower part of the sample in the late drying stage is the intrinsic mechanical factor responsible for the initial concave curling deformation and the subsequent fallback and convex curling phenomenon. Curling deformation in the present model is compared with other existing explanations on desiccation curling. The influences of evaporation rate and hydraulic conductivity on the model performance were also discussed. It is found that a higher evaporation rate and a lower hydraulic conductivity would result in a higher extent of curling during drying.

Structured plasmonic beam: in-plane manipulation of light at the nanoscale

The brief review on recent approaches on the formation of a new class of subwavelength scale localized structured surface plasmon polaritons (SPP) beams is discussed. For the Janus-like particle (including the geometrically symmetric particles with different dielectrics) the morphology of the field localization area and its properties depends on the particle shape and material. Plasmonic hook (PH) beam does not propagate along straight line but instead follow curved self-bending trajectory. Wavefront analysis behind of such symmetric and asymmetric mesoscale rectangle structure reveals that the unequal phase of the transmitted plane wave results in the irregularly concave deformation of the wavefront inside the dielectric which later leads to creation of the PH. Such dielectric structures placed on metal film enable the realization of new ultracompact wavelength-selective and wavelength-scaled in-plane nanophotonic components. SPP have potential to overcome the constrains on the speed of modern digital integrated devices limitation due to the metallic interconnects and increase the operating speed of future digital circuits.

A novel device for in-situ force measurements during laser powder bed fusion (L-PBF)

PurposeThe purpose of this paper is to detail the design and first use of a force transducer device to study the development of forces during the laser-powder bed fusion (L-PBF) process from which residual stresses can be inferred.Design/methodology/approachThe proposed novel device consists of an array of load cells for in-situ measurement of forces over time during the L-PBF additive manufacturing process. Measurements of the developed forces layer by layer were recorded in a first build using a 67-degree rotating scan strategy using Inconel 625 build material.FindingsPreliminary experimental results from in-situ measurements using a 67-degree rotating scan strategy showed that the forces induced in the first five layers represented approximately 80% of the maximum on completion of the build and were distributed such as to induce concave deformation of the part, i.e. tension in the centre and compression at the edges of the part.Originality/valueThis paper describes a novel device for in-process measurement of the spatial distribution and time-varying nature of the forces induced during the L-PBF process as well as an evaluation of the residual forces following the completion of the build.