Compressive Plastic Research Articles

Theoretical Analysis of Shaft Wall Damage and Failure Under Impacting of Ore-Rock Falling in Vertical Ore Pass

The impact of ore-rock blocks on the shaft wall of a vertical ore pass is a crucial cause of shaft wall damage and failure. Based on the structure and parameters of the ore pass in a case mine, the first collision’s position of the ore-rock block with respect to the ore pass wall and the angle between the impacting direction of the ore-rock block and the horizontal plane before and after the collision are investigated via a kinematic analysis. The normal and tangential analysis models of ore rock impacting the shaft wall are established and analyzed based on contact mechanics. The results show that: (1) based on the kinematic analysis of ore rock moving in the ore pass and on the colliding condition of the ore-rock block the first time that it collides with the ore pass wall, the coordinates and angles of the collision are proposed; (2) the impacting process of ore rock is categorized into elastic compression, elastic–plastic compression, and rebound of the shaft wall material. The relationship between the normal impact force and the penetrating depth is determined, and the slipping distance of the ore-rock block along the shaft wall and the lost volume of the shaft material are established. (3) The wall material’s normal, tangential, and total restitution coefficient is acquired. (4) The total lost volume during the collision is obtained through the analysis and solution of the model. (5) Based on the characteristics and parameters of the ore pass in the case mine, the influence of the impact velocity and angle of the ore-rock block on the restitution coefficient, maximum normal intrusion depth, maximum tangential displacement, and volume loss of the shaft wall are analyzed by using relevant formulas.

On the thermal dissipation in the thermomechanical treatment of metal materials

The results of plastic compression of steels and alloys of different chemical compositions at temperatures and rates of plastic deformation corresponding to common thermomechanical treatment (TMT) regimes are considered. The features of the diagrams σ (ε, έ, Т) are revealed. The processes of strain accumulation and thermal dissipation are accompanied by structural rearrangements. Depending on the chemical composition and hot compression modes, structural transformations occur self-organized, with the possibility of excitation of oscillations and the formation of dissipative solitons.

A critical state μ(I)-rheology model for cohesive granular flows

The dynamic behaviour of granular media can be observed widely in nature and in many industrial processes. Yet, the modelling of such media remains challenging as they may act with solid-like and fluid-like properties depending on the rate of the flow and can display a varying apparent friction, cohesion and compressibility. Over the last two decades, the $\mu (I)$ -rheology has become well established for modelling granular liquids in a fluid mechanics framework where the apparent friction $\mu$ depends on the inertial number $I$ . In the geo-mechanics community, modelling the deformation of granular solids typically relies on concepts from critical state soil mechanics. Along the lines of recent attempts to combine critical state and the $\mu (I)$ -rheology, we develop a continuum model based on modified cam-clay in an elastoplastic framework which recovers the $\mu (I)$ -rheology under flow. This model permits a treatment of plastic compressibility in systems with or without cohesion, where the cohesion is assumed to be the result of persistent inter-granular attractive forces. Implemented in a two- and three-dimensional material point method, it allows for the trivial treatment of the free surface. The proposed model approximately reproduces analytical solutions of steady-state cohesionless flow and is further compared with previous cohesive and cohesionless experiments. In particular, satisfactory agreements with several experiments of granular collapse are demonstrated, albeit with shear bands which can affect the smoothness of the surface. Finally, the model is able to qualitatively reproduce the multiple steady-state solutions of granular flow recently observed in experiments of flow over obstacles.

ITZ properties of LWA surroundings in high strength mortar according to LWA/sand with relative humidity

The internal moisture content significantly influences the quality and durability of cement-based composite materials. However, reliable methods to analyze the moisture retention of concrete and mortar are lacking, particularly in relation to internal curing with lightweight aggregates (LWA). In this study, the internal moisture retention of mortar with different lightweight aggregate/sand (L/S) ratios was investigated while considering the absorption characteristics of LWA. Furthermore, the impact of internal moisture retention on the development of the interface transition zone (ITZ) between the LWA and cement matrix was analyzed. Additionally, compressive strength development was evaluated over different curing periods (3, 7, 28, 56, and 90 days) under internal curing conditions. The results showed that the L/S ratio, which is directly proportional to the amount of moisture absorbed, enhanced the compressive strength and plastic hardness, contributing to the development of depletion of internal moisture in the mortar was could be observed. The moisture consumption for different types of LWA was analyzed using CT scanning. XRD and SEM-EDS analyses confirmed the abundant presence of hydration products in the ITZ. This study demonstrates that the L/S ratio that considers the LWA absorption characteristics, can serve as a critical parameter for precisely correlating the curing time and compressive strength in internally cured mortars.

A novel BCC-L21-BCC hierarchical heterostructure high entropy alloy with excellent corrosion resistance and mechanical properties in as-cast state

In this paper, a novel as-cast CrFeNiAl0.35Si0.1Ti0.1 high entropy alloy (HEA) with micron-to-nano hierarchical heterostructure was designed, and its microstructure, mechanical properties and corrosion resistance have been systematically investigated. It is found that, this novel HEA exhibits well-dispersed L21 phase with various sizes from micron-scale to nano-scale in the BCC matrix, while nano-sized BCC lamellas could also emerge in the L21 phase with large diameter. Moreover, this HEA exhibits not only excellent corrosion resistance in 3.5 wt% NaCl solution that close to super-stainless steels, but also high mechanical properties combining yield strength of 1712 ± 56 MPa, compressive plasticity of 21.2% ± 0.5% and hardness of ∼560 Hv. Such outstanding comprehensive properties for this HEA are possibly resulted from the complex hierarchical BCC-L21-BCC heterostructure with stable passive film and low diversity in work function between different phases. This work provides a novel route in the development of high-performance corrosion-resistant HEAs for structural and coating applications.

Сompression and Shear of an Ideal-plastic Wedge with a Rough Stamp (Frictional Contact Model)

The transfer of shear force through frictional contact on rough surfaces of precompressed plastic bodies is studied. As a contact model, we consider the problem of plastic compression of a wedge by a rough flat stamp with the condition of Prandtl friction on the contact surface. A technique is proposed for determining the maximum shear load perceived by frictional contact.

Analyses of bending performance of innovative paper-based sandwich beams with cup-box core

Paper-based materials are being alternative candidates to build load-bearing components for the high demanding building sector to be committed to the green transition, but more knowledge of structural mechanics of such components is needed. In this work, three categories of innovative load-bearing sandwich beams with cup-box core fully made of different paper materials were produced, tested and analyzed in four-point bending. The first failure mode was observed at the top facesheets due to the low compressive strength of paper materials; Beams with thin facesheets had premature buckling failure, whereas those with thicker facesheets exhibited ductility reaching higher deflection before the compressive failure. The developed finite element model, calibrated with the experiments for the equivalent bending and shear rigidities, provided figures of the modulus of the facesheet as well as the properties of the core. Furthermore, the compressive plasticity behavior of the facesheets was assessed by fitting the model with load-deflection curves from the tests. Using the model for the structural optimization of the thickness and height of the core, the work suggests optimal values 3 times higher than the original ones.

Dense Collagen I as a Biomimetic Material to Track Matrix Remodelling in Renal Carcinomas.

Aims: Renal tissue is a dynamic biophysical microenvironment, regulating healthy function and influencing tumor development. Matrix remodelling is an iterative process and aberrant tissue repair is prominent in kidney fibrosis and cancer. Biomimetic 3D models recapitulating the collagen composition and mechanical fidelity of native renal tissue were developed to investigate cell-matrix interactions in renal carcinomas. Methods: Collagen I and laminin hydrogels were engineered with renal cancer cells (ACHN and 786-O), which underwent plastic compression to generate dense matrices. Mechanical properties were determined using shear rheology and qPCR determined the gene expression of matrix markers. Results: The shear modulus and phase angle of acellular dense collagen I gels (474 Pa and 10.7) are similar to human kidney samples (1410 Pa and 10.5). After 21 days, 786-O cells softened the dense matrix (∼155 Pa), with collagen IV downregulation and upregulation of matrix metalloproteinases (MMP7 and MMP8). ACHN cells were found to be less invasive and stiffened the matrix to ∼1.25 kPa, with gene upregulation of collagen IV and the cross-linking enzyme LOX. Conclusions: Renal cancer cells remodel their biophysical environment, altering the material properties of tissue stroma in 3D models. These models can generate physiologically relevant stiffness to investigate the different matrix remodelling mechanisms utilized by cancer cells.

A novel Zr-based metallic glass composite and its plasticizing mechanism

A novel Zr-based metallic glass composite was prepared utilizing a die casting process in this study. This composite utilizes high-porosity open-pored foam metal as the second phase and takes advantage of the unique distribution characteristics of this phase to achieve structural characteristics resembling hard regions surrounded by soft regions. This facilitates the formation and interleaving of numerous shear bands during the deformation process of the composite, resulting in work-hardening capability and favorable compressive plasticity. The results indicate that the compressive strength of the metallic glass composites containing 2.72 % foamed Ni and 3.71 % foamed Cu respectively does not decrease significantly compared to single-phase metallic glass, while their compressive plasticity increases from 1.60 ± 0.46 % to 12.21 ± 1.04 % and 13.01 ± 1.15 %, respectively. This study not only uncovers the preparation method and plasticizing mechanism of a novel metallic glass composite, but also offers a fresh perspective for the design of high-plasticity metallic glass composites.

A detailed study on void growth and crack-void interaction in plastically compressible bilinear hardening and trilinear hardening-softening-hardening solids

This paper provides detailed investigations on void growth and crack-void interaction ahead of a moving crack-tip for a mode I crack in plastically compressible solid. A finite strain elastic-viscoplastic material model with hardening-hardening and hardening-softening-hardening hardness functions is used in the finite element simulation. The plastic compressibility leads to an increased crack opening displacement. The plastic compressibility together with material softening considerably increase stress triaxiality and decrease the void and crack growth. For plastically compressible solids, void growth is more in normal direction to the crack plane and increase in initial void size is accompanied by decrease in the crack and void growth.

Mechanical behaviour and macro-micro failure mechanisms of frozen weakly cemented sandstone under different stress paths

Significant unloading failure zones in artificial freezing shaft sinking projects in western China are primarily caused by stress release. To investigate the deformation and failure mechanisms of frozen weakly cemented sandstone (FWCS), three groups of triaxial unloading tests were conducted under different initial principal stresses (σ₃ = 3, 6, and 10 MPa) with an unloading rate of 0.05 MPa/s. Scanning electron microscopy (SEM) was employed to examine the micro-fracture characteristics of the failure surfaces. The results revealed that, compared to traditional triaxial and room-temperature triaxial compression tests, the strength and plastic deformation characteristics of FWCS are significantly weakened under unloading conditions. However, lateral deformation, particularly volumetric strain, increased markedly, exhibiting pronounced dilatancy characteristics, especially along stress path III (i.e., post-peak axial stress loading with confining pressure unloading). Unloading leads to a reduction in cohesion and an increase in the internal friction angle of FWCS, with the most significant changes observed along stress path IV (i.e., pre-peak constant axial displacement loading with confining pressure unloading). Macroscopic and microscopic analyses indicate that the failure mechanism of FWCS under complex unloading stress paths is driven by the rapid accumulation of energy caused by unloading, which results in the development and propagation of axial and circumferential cracks, widespread particle breakage, and the formation of inter-granular and trans-granular fractures, as well as shear scratches at the micro level, ultimately manifesting macroscopically as shear-tensile composite failure.

Structure and mechanical properties of low-density AlCrFeTiX (X = Co, Ni, Cu) high-entropy alloys produced by spark plasma sintering

In this study, low-density (< 6 g/cm3) AlCrFeTiX (x = Co, Ni, Cu) high-entropy alloys were produced by mechanical alloying and spark plasma sintering (SPS), and their structures and mechanical properties after SPS and annealing at 1000 °C for 24 h were reported. Both after SPS and annealing, the AlCrFeTiX (x = Co, Ni, Cu) alloys consisted of an L21 matrix phase with embedded bcc and C14 Laves phase particles. All the alloys had a nano-sized structure after SPS that retained in the AlCrFeTiCo and AlCrFeTiNi alloys after annealing. In the AlCrFeTiCu alloy, the annealing led to a coarsening, with an increase in the size of structural constituents above 1 μm. Compression tests showed that the AlCrFeTiX (x = Co, Ni, Cu) alloys after SPS were brittle at 25 °C, but the AlCrFeTiCo alloy exhibited the highest peak strength of 3792 MPa. At 600 °C, the AlCrFeTiCo alloy after SPS also demonstrated the best performance, with the yield strength, peak strength, and plastic strain of 1960 MPa, 2121 MPa, and 1.8 %, respectively. The annealing did not eliminate the room-temperature brittleness, but improved the mechanical properties at 600 °C. The AlCrFeTiCo alloy showed a 15 %-increase in yield strength (2264 MPa) and more than 2.5 times higher compressive plasticity (4.7 %). The AlCrFeTiNi alloy became more ductile (1 %) and stronger (2200 MPa). For the AlCrFeTiCu alloy, the annealing had a negative effect that resulted in a halved plasticity at 600 °C. The AlCrFeTiCo and AlCrFeTiNi alloys after annealing showed record-high specific yield strength values at 600 °C, which were 383 and 371 MPa*cm3/g, respectively. With these values, the AlCrFeTiCo and AlCrFeTiNi alloys outperformed all the low-density medium-/high-entropy alloys available in literature to date obtained both by SPS or conventional casting. The structure formation and mechanical properties, as well as the response of these features to annealing, were extensively discussed.

A strategy for designing Ti-based in-situ bulk metallic glass composites with tailored structural metastability using conventional titanium alloys

The metastability of the dendritic phase is crucial in determining the mechanical properties and mechanisms of the Ti-based in-situ dendrite-reinforced bulk metallic glass composites (BMGCs). However, tailoring the metastability effectively remains challenging. In this study, we propose a straightforward and effective strategy to tailor the dendrites composition and metastability using conventional Titanium alloys. Initially, six common Titanium alloys with increasing content of β-stabilizing elements such as Ti, Ti–6Al–4V, Ti–13Nb–13Zr, Ti–15Mo, Ti–12Mo–6Zr–2Fe and Ti-4.5Fe-6.8Mo-1.5Al were selected. Subsequently, a series of in-situ dendrite-reinforced BMGCs denoted as T1-T6 were designed by alloying these Titanium alloys with a specific amorphous alloy. It was found that the microstructure, stability and mechanical behaviors of these composites change significantly as the content of β-stabilizing elements in the dendritic phase increases monotonically. Based on their microstructure and mechanical behaviors, these composites can be classified into three categories: T1, T2 and T3, T4-T6. The T1 alloy exhibits brittle deformation characteristics due to the significantly higher elastic modulus of the dendritic phase. In contrast, the T2 and T3 alloys demonstrate good tensile plasticity and remarkable work-hardening ability, attributed to the metastable β phase undergoing stress-induced phase transformation during deformation. On the other hand, the T4-T6 alloys, consisting of stable β phase, deform via dislocation slip, resulting in a higher yielding stress and compression plasticity. The composition design strategy presented in this study, along with the correlation between mechanical behaviors and dendrite stability, may offer a novel perspective for the development of Ti-based in-situ dendrite-reinforced BMGCs.

Trabecular meshwork cell differentiation in response to collagen and TGFβ-2 spatial interactions

Primary open-angle glaucoma (POAG) is currently the most prevalent cause of irreversible blindness globally. To date, few in vitro models that can faithfully recapitulate the complex architecture of the trabecular meshwork (TM) and the specialised trabecular meshwork cell (TMC) characteristics that are local to the structurally opposing regions. This study aimed to investigate the parameters that govern TMC phenotype by adapting the extracellular matrix structure to mimic the juxtacanalicular tissue (JCT) region of the TM. Initially, TMC phenotypic characteristics were investigated within type I collagen matrices of controlled fiber density and anisotropy, generated through confined plastic compression (PC). Notably, PC-collagen presented biophysical cues that induced JCT cellular characteristics (elastin, α-β-Crystallin protein expression, cytoskeletal remodelling, increased mesenchymal markers and JCT-specific genetic markers). In parallel, a pathological mesenchymal phenotype associated with POAG was induced through localised transforming growth factor -beta 2 (TGFβ-2) exposure. This resulted in a profile of alternative mesenchymal states (fibroblast/smooth muscle or myofibroblast) displayed by the TMC in vitro. Overall, the study provides an advanced insight into the biophysical cues that modulate TMC fate, inducing a JCT-specific phenotype and transient mesenchymal characteristics that reflect healthy and pathological scenarios. Statement of significanceGlaucoma is a leading cause of blindness, with a lack of long-term efficacy within current drug candidates. Reliable trabecular meshwork (TM) in vitro models will be critical for enhancing the fields understanding of healthy and disease states for pre-clinical testing.Trabecular meshwork cells (TMCs) display heterogeneity throughout the hierarchical TM, however our understanding into recapitulating these phenotypes in vitro, remains elusive. This study hypothesizes the importance of specific matrix/growth factor spatial stimuli in governing TMCs phenotype. By emulating certain biophysical/biochemical in vivo parameters, we introduce an advanced profile of distinct TMC phenotypic states, reflecting healthy and disease scenarios. A notion that has not be stated prior and a fundamental consideration for future 3D TM in vitro modelling.

Ultrasonic powder consolidation of metallic glass/Al-6061 composites

Traditional powder consolidation methods for fabricating metallic matrix composites often require high temperatures, high pressures, and substantial energy consumption. Therefore, developing new processing technologies that can manufacture composites rapidly, efficiently, and economically is crucial. This study introduces ultrasonic powder consolidation process as a novel strategy for fabricating and tuning metallic glass (MG) and aluminum alloy composites. By optimizing the mass ratios of Zr55Cu30Ni5Al10 (at.%) MG to Al-6061 powders, a diverse range of composites with tailored compressive strength and plasticity was achieved. Mechanical testing showed that increasing the aluminum content improved plasticity while maintaining significant strength. Notably, the composite with a 5:5 mass ratio exhibited the best balance of mechanical properties. Morphological characterizations demonstrated excellent densification and uniformity in the composites, with no visible defects and relative densities ranging from approximately 92 %–99 %. Detailed microstructural analysis revealed the formation of a well-bonded interface with a diffusion layer, confirming the metallurgical bonding was facilitated by ultrasonic vibration. Furthermore, the ultrasonic consolidation process enabled the successful fabrication of complex shapes, such as star and gear components, demonstrating the method's potential for advanced manufacturing. These results show that the ultrasonic powder consolidation process is a viable and efficient approach for producing high-quality MG/Al-6061 composites with enhanced mechanical performance and application versatility.

Mechanical properties of teguline clay pellet mixtures during continuous oedometric compression

Clay pellet mixtures are generally compressed to improve their engineering performance. Deepening the comprehension of the mechanical properties of these mixtures in the complete compression process facilitates the benefit to the engineering design and their utilization. In this study, the effects of soil grain size distribution, water content and dry density on the mechanical properties and microstructure of Teguline clay pellet mixtures during a continuous oedometric compression process are explored. Three types of soil pellet mixtures, including mixture A (grain size ≤5 mm), mixture B (≤ 0.4 mm) and mixture C (2–5 mm), were prepared with different water contents of 7%, 8% and 12% respectively. Subsequently, continuous oedometeric compression was undertaken to explore their mechanical behaviours of the soil pellet mixtures. After that, the microstropic structures of the compacted pellet mixtures were investigated using mercury intrusion porosimetry (MIP). The results indicated that mixture A has a minimal initial packing density of pellet mixtures, while mixture C has a maximum one at the initial compression stage. After completion of compression, the compression curves of the pellet mixtures tended to converge uniformity at a semilogarithm coordinate as the vertical stress increased. All of the compression curves presented a concave shape at the plastic compression stage, which is significantly influenced by grain size distribution and water content. In contrast, the elastic compression and rebound behaviours are little affected by the grain size distribution and water content. As far as the microstructure is concerned, compacted samples prepared by mixture A or C presented a unimodal pore structure, while those by mixture B showcased a bimodal pore structure. In comparison with the unimodal pore distribution of the undisturbed stiff clay, the compacted samples displayed a pseudo-unimodal pore distribution because the inter-aggregate pores still existed. A double tangent method was proposed to determine the delimiting pore diameter of the pseudo-unimodal pore distribution curves and found that the delimiting pore diameter decreased with the increase of dry density and water content. Moreover, the inflexion point for the pore diameter of compacted samples prepared by coarse soil was larger than that of fine soil. Combining this work with previous research, it was found that the high compression of coarse soil easily causes the pseudo-unimodal shape, which is also impacted by water content and particle properties. This work could help deepen the understanding of the mechanical characteristics and microstructure of the stiff clay pellet mixtures during continuous oedometric compression.

Synergistic enhancement of strength and plasticity in Ti–Cu alloys by elimination of pearlite microstructure through Zr alloying

The eutectoid Ti–Cu alloy has the advantages of high strength and hardness. However, the pearlite eutectoid structures with coupled α + Ti2Cu lamellae result in low plasticity. In this study, a Zr alloying method is proposed to suppress the formation of lamellar pearlite and promote a bainite-like morphology. Increasing the Zr content can transform the α lamellae into rod-like laths and the Ti2Cu lamellae into dispersed particles, thereby reducing their embrittlement effect. The α laths are further refined to about 0.27 and 0.37 μm with 30% and 50% Zr addition, resulting in strong grain boundary strengthening effects. As a result, the mechanical properties are enhanced after Zr alloying. The best combination of compressive yield strength, maximum strength, and plasticity is achieved with 30% Zr addition, which is about 1040 MPa, 2505 MPa, and 33%, respectively. The results in this study can offer valuable insights into microstructure optimization and performance enhancement in active eutectoid Ti–Cu systems.

A Dynamic Damage Constitutive Model of Rock-like Materials Based on Elastic Tensile Strain

To accurately characterize the damage of rock-like materials under simultaneous or alternating tensile and compressive loading, a dynamic damage constitutive model for rock-like materials based on elastic tensile strain is developed by integrating the classical compressive plastic damage model and the tensile elastic damage model. The model is based on the Holmquist–Johnson–Cook (HJC) and Kuszmaul (KUS) models, categorizing the element stress state into tensile and compressive states through positive and negative elastic volumetric strain. It utilizes elastic tensile strain to enhance the calculation method for tensile cracks, determining the tensile strength of the principal direction based on the contribution rate of tensile principal stress for uniaxial/multiaxial loading. Additionally, it establishes a maximum elastic tensile strain rate function to rectify the model’s effect on the tensile strain rate. Through the LS-DYNA subroutine development, the model proficiently delineates the distribution of ring-shaped cracks on the frontal side and strip-shaped cracks on the rear side of the reinforced concrete slab subjected to impact loading. Numerical simulations demonstrate that the model provides more accurate damage prediction results for stress conditions involving simultaneous or alternating compression and tension, offering valuable insights for damage analysis in engineering blasting or impact penetration.

Dual skin effect and deep heterostructure of titanium alloy subjected to high-frequency electropulsing-assisted laser shock peening

Laser shock peening, an advanced technology for severe surface plasticity peening, encounters challenges such as shallow hardened layers and surface spalling when dealing with difficult-to-machine materials. In this study, we introduced a high-frequency electropulsing-assisted laser shock peening (HFEP-LSP) technique that coupled laser shock peening with high-frequency electric pulses to achieve a significant and deeper plastic deformation layer. In the HFEP-LSP technique, we first considered the dual “skin effect”, which coupled the skin effect of high-frequency electric pulses with the “skin effect” of the mechanical effect induced by the laser shock wave. An integrated experimental platform comprising an electric pulse generator, laser shock peening equipment, and a control system was built. A >1.6 mm deep compressive residual stress layer was obtained, and the depth of the plastic deformation layer increased by 83.3 %. Furthermore, we elucidated the dual “skin effect”-induced complex heterostructure and βm phase transition. A comprehensive analysis revealed the factors contributing to the deeper strengthening layer induced by HFEP-LSP, including the compressive residual stress and plastic deformation layers. In addition, the effects of laser shock peening and HFEP-LSP on the mechanical properties were investigated. Compared to the annealed samples, the ultimate tensile strength and elongation of the HFEP-LSP-treated samples were increased by 12.3 % and 57.1 %, respectively, with a fatigue life improvement of 176.4 %. The mechanism of synergistic improvement in strength and ductility was demonstrated.

A new combined fabrication process to shape small flexure hinges

This paper presents a new combined fabrication method, named 3D-PLAST, aimed at overcoming inherent limitations of conventional additive manufacturing techniques when producing small flexure hinges in compliant mechanisms. Flexure hinges play a crucial role in various applications, offering advantages such as cost reduction, increased precision, and weight reduction. However, traditional additive manufacturing proves challenging in achieving satisfactory mechanical properties when manufacturing small-size hinges. To overcome these limitations, the 3D-PLAST process combines fused filament fabrication with compressive plastic deformation. This hybrid process exploits the advantages of both techniques, i.e., flexibility, low cost, and ease of use. This process enables the fabrication of small-size mechanisms with good dimensional accuracy. Finally, the paper reports experimental tests on two materials comparing flexure hinges manufactured by 3D-PLAST versus 3D printing methods to demonstrate the effectiveness of the proposed process.