Lower Yield Stress Research Articles

Study on strain rate dependence and energy absorption characteristics of two aluminum alloys 7A62 and 7085

The dynamic compression properties of two aluminum alloys 7A62 and 7085 were tested using Split Hopkinson Pressure Bar (SHPB ) technique. The effects of strain rate on yield stress and dynamic energy absorption characteristics of the two materials were analyzed. The critical strain rate and the maximum energy absorbed before shear failure occurred of the two materials were given. The results showed that both the two materials show a strong strain rate dependence effect, and the yield stress increased with increasing strain rate. The aluminum alloy 7085 has a lower yield stress than 7A62 under the same strain rate level. But it has a better energy absorption characteristic than 7A62 for its good plasticity.

Rheological study of heavy cement grouts with physical and chemical characterization of barite powder

This study aims to prepare heavy cement grouts mixtures with different contents of barite powder. Different analytical techniques were used to characterize barite. The Fourier transform infrared and Raman spectroscopy showed that barite has C3ν as a symmetry site. The scanning electron microscopy coupled with X-ray, and X-ray fluorescence showed that barite is the main mineral appearing as platelets. The study of physical properties of mixtures showed that 15% of barite can maintain a normal consistency (5–6 mm). The setting time was inversely proportional to BaO content. The steady-state flow was conducted using a controlled-stress rheometer. The obtained results showed that the mixtures exhibit shear thinning behavior and the presence of barite leads to different rheological behavior as a function of the percentage used. The critical shear rate was proportional to barite content in mixtures prepared by addition and inversely proportional in those prepared by substitution. Concerning yield stress, substitution by 15% leads to a best formulation characterized by low yield stress compared to controller grout.

Rheological Properties of Cemented Paste Backfill with Alkali-Activated Slag

This study investigates the time-dependent rheological behavior of cemented paste backfill (CPB) that contains alkali-activated slag (AAS) as a binder. Rheological measurements with the controlled shear strain method have been conducted on various AAS-CPB samples with different binder contents, silicate modulus (Ms: SiO2/Na2O molar ratio), fineness of slag and curing temperatures. The Bingham model afforded a good fit to all of the CPB mixtures. The results show that AAS-CPB samples with high binder content demonstrate a more rapid rate of gain in yield stress and plastic viscosity. AAS-CPB also shows better rheological behavior than CPB samples made up of ordinary Portland cement (OPC) at identical binder contents. It is found that increasing Ms yields lower yield stress and plastic viscosity and the rate of gain in these parameters. Increases in the fineness of slag has an adverse effect on rheological behavior of AAS-CPB. The rheological behavior of both OPC- and AAS-CPB samples is also strongly enhanced at higher temperatures. AAS-CPB samples are found to be more sensitive to the variation in curing temperatures than OPC-CPB samples with respect to the rate of gain in yield stress and plastic viscosity. As a result, the findings of this study will contribute to well understand the flow and transport features of fresh CPB mixtures under various conditions and their changes with time.

Effects of water content, water type and temperature on the rheological behaviour of slag-cement and fly ash-cement paste backfill

The pumping ability and placement performance of fresh cemented paste backfill (CPB) in underground mined cavities depend on its rheological properties. Hence, it is crucial to understand the rheology of fresh CPB slurry, which is related to CPB mixture design and the temperature underground. This paper presented an experimental study investigating the effects of binder type, content, water chemical properties and content, and temperature, on the rheological properties of CPB material prepared using the tailings of a copper mine in South Australia. Portland cement (PC), a newly released commercially manufactured cement called Minecem (MC) and fly ash (FA) were used as the binders added to the mine tailing materials. Various amounts of two different water types were added to the mixtures in the preparation of backfill material slurry. Six different temperatures ranging from 5 to 60 °C were to investigate the effect of temperature on CPB rheology. Overall, the increasing water content and decreasing temperature lead to lower yield stress. Based on the results obtained from the rheological properties of CPB slurry, it was found that at room temperature (25 °C), with regards to the unconfined compressive strength (UCS) performance, the replacement of 4% PC mixed CPB (28 days UCS 425 kPa) to 3% MC mixed CPB (28 days UCS 519 kPa), reduced the slurry yield stress from 210.7 to 178.5 Pa. The results also showed that the chemical composition of water affects the yield stress of CPB slurry and that MC mitigates the negative effect of mine-processed water (MW) and thus lead to improve the rheological properties of the slurry. However, the results suggested that the rheological properties of a mixture using MC is very sensitive to the water volume and temperature change. Therefore, using MC in backfill requires better quality control in slump mixing.

An analysis of fracture in staggered mineralized collagen fibril arrays

Fracture resistance of bone arises from various toughening mechanisms at multiple hierarchical levels. Despite considerable effort devoted to identification of fracture mechanisms associated with the ingenious hierarchical structure of bone, how the structural elements at the submicroscale contribute to the toughness of bone is largely unknown. In this study, the calculations are carried out for a biological composite consisting of mineralized collagen fibrils (MCFs) embedded in an extrafibrillar matrix (EFM), and the individual effects of the parameters associated with energy dissipation in the EFM are elucidated. The intrafibrillar plasticity through mineral/collagen sliding, the interfibrillar sliding and the mechanism of energy dissipation of the EFM are incorporated in the computational model. Furthermore, the staggered arrangement of MCFs and the fracture of the interfaces between MCFs and the EFM are accounted for. It is found that high stiffness of the EFM gives rise to enhanced energy dissipation in the EFM and reduced damage of the MCF/EFM interface. In addition, plastic deformation in MCFs is activated by the high stiffness of the EFM, which promotes energy dissipation, thereby enhancing toughness of the MCF arrays. The low initial yield stress of the EFM plays the roles in increasing energy dissipation in the EFM, promoting plastic deformation in MCFs and mitigating fracture of the MCF/EFM interface. The fracture behavior of MCF arrays is also influenced by the post-yield strain hardening behavior of the EFM; strong strain hardening enables diffuse damage of the MCF/EFM interface. We further reveal that strong post-yield strain hardening of MCFs increases the propensity of damage of the MCF/EFM interface and delays plastic deformation in MCFs. The findings of this study can not only shed new light on the fracture mechanisms of the staggered MCF arrays, but also provide mechanistic insights into bioinspired materials design.

Effect of interparticle action on shear thickening behavior of cementitious composites: modeling and experimental validation

Shear thickening is a behavior of a material that displays an increase in viscosity with increasing shear rate. Research has indicated that in self-consolidating concrete (SCC), shear thickening is primarily caused by the formation of “particle clusters” due to collisions of particles in the low yield stress of the fluid material matrix of SCC at a high flow rate. Based on this theory, a previously developed particle–fluid model was modified and applied to predict the relationship between the shear stress and shear strain rate of cementitious composites that exhibit shear thickening behavior. The rheology test results indicated no apparent shear thickening behavior was observed for SCC paste mixtures while distinct shear thickening behavior was observed when the introduced fine aggregate volume fraction increased up to 40%. The modified model showed a power function between the shear stress and shear rate that could well capture the shear thickening behavior of mortar mixtures with various aggregate volume fractions and that agreed well with the results of the experimental study. The modified model also demonstrated that aggregate particles could generate local transient particle clusters during interactions due to the particles’ varying velocities, yielding shear thickening.

Cement asphalt mortar for high-speed rail

During the past two decades, the high-speed rail technology has been developed rapidly in China. At present, China has the most complete technology system, the most integrated capacity, the longest operating mileage and the highest operating speed. Many new structures, technologies and materials have been developed and employed in the construction of the infrastructure of high-speed rail. Ballastless track systems have been used as a key component for the high-speed rail line. Among which, three types of ballastless slab track, i.e., CRTS I, II and III slab tracks, are implemented in the backbone lines in China, such as Beijing-Shanghai line, Haerbin-Dalian line. The ballastless slab track systems are different in structural forms and materials employed from each other. Cement asphalt (CA) mortar is the key engineering material for CRTS I and II slab tracks of high-speed rail, which has significant effects on the track dynamics, durability and riding comfort of slab ballastless track. In order to meet the needs for massive construction of high-speed rail in China, intensive studies on CA mortar have been carried out, and complete set of technology with independent intellectual property rights have been established. This gives solid support for the construction of 7×103 km ballastless slab track in China. Approximately, 1.5×106 m3 CA mortar has been used in the construction of high-speed rail. In practice, fresh CA mortar is cast into the narrow chamber enclosed by prefabricated slab and base concrete plate to form a “sandwich” structure. The cushion layer of CA mortar is required to have strong bonding or close contact with the slab situated above. The construction quality of CA mortar cushion layer is crucial to the quality of track system, and thus high-speed rail lines. This paper briefly introduces the development history of CA mortar in China, mainly gives a comprehensive overview on the rheology, early deformation, microstructure, mechanical properties and durability of CA mortar, from the perspective of material science and practical engineering. China carried out preliminary study on CA mortar for railway at 1970s, and intensive studies since 2006. CA mortar is an organic-inorganic composite, which is either cement-based or asphalt-based material, depending on cement-to-asphalt ratio. Cement hydrates provide rigid framework, while asphalt agglomerates provide damping ability for the material. The rheological properties of fresh CA mortar are similar to those of fresh cement mortar. In order to fill up the narrow and sealed space, CA mortar should have relatively high viscosity, low yield stress and appropriate thixotropy. Aluminum powder is used in combination with expansive agent to compensate the shrinkage of CA mortar. The pore structure of CA mortar is similar to that of cement mortar. Due to the low strength of asphalt, mercury intrusion porosity (MIP) test is not suitable for CA mortar. Nuclear magnetic resonance (NMR) techniques have been developed to characterize the pore structure of CA mortar. The mechanical properties of CA mortar mainly depend on cement-to-asphalt ratio, and barely depend on water-to-cement ratio. Viscoelastic properties of CA mortar are temperature-dependent, and can be well characterized by dynamic mechanical thermal analysis (DMTA). The durability of CA mortar is mainly associated with water which causes calcium leaching and softening. The different deformation between slab and CA mortar layer due to temperature and aging of asphalt may also cause the durability problem of CA mortar. Based on the established models, CA mortar cushion layer can meet the designed service life.

Experimental investigation on the mechanical and rheological properties of high-performance concrete (HPC) incorporating sinking bead

In this paper, the effects of a type of sinking bead, which is separated from fly ash, on the rheology and hardened performance of High-Performance concrete (HPC) are investigated. Based on the modified Andreasen & Andersen particle packing model, the sinking bead was added by partly replacing the portland cement to achieve the designed HPC. The rheology, mechanical properties, and microstructure of the developed HPC are thoroughly investigated through a serious of experiments. It is discovered that the smaller particle sized sinking bead can act as “ball-bearings” which can overcome the interval friction, so the fresh sinking bead HPC paste possesses better thixotropic property, shear thinning rheology behaviour, lower yield stress, and plastic viscosity than the fly ash based HPC paste under the same dosage. Moreover, the experimental results have demonstrated that the sinking bead based HPC have excellent electrical resistivity, compressive strength, flexural strength, and microstructure at the hardened state. In addition, it is discovered that the sinking bead based HPC shares very similar microscopic product and micro-morphology to the fly ash based HPC.

Effects of volume fraction of fine grains on the tensile creep properties of a hot-deformed Mg-Gd-Y-Zr alloy

The creep properties of a hot-compressed Mg-9Gd-4Y-0.5Zr alloy with different volume fractions (VFs) of fine grains were investigated at 523 K, 548 K and 573 K. Based on the initial VFs of fine grains, the samples were divided into four groups including VF0 (VF = 0), VF0.2 (VF = 20%), VF0.5 (VF = 50%) and VF0.8 (VF = 80%) samples. The VF0.8 sample had the highest yield stress at room temperature, followed by the VF0.5 and VF0.2 samples, and the VF0 sample had the lowest. But after creep tests, the VF0.2 and VF0.5 samples had better creep resistance compared to the VF0 and VF0.8 samples at all the three temperatures. The creep life was shortest for the VF0 sample due to its lowest yield stress. The VF0.2 and VF0.5 samples were dominated by dislocation climb and pyramidal <c+a> slip during creep testing. Deformation bands formed by pyramidal <c+a> dislocations and obvious dynamic precipitation strengthened the creep resistance. Besides, the serrated grain boundaries were formed by the combination of coarse and fine grains, which absorbed dislocations and further improved the creep resistance. The VF0.8 sample was weakened by the precipitate-free zones (PFZs) formed along the high densities of grain boundaries. Although fine grains could improve yield stress, the excessive fine grains deteriorated the creep resistance owing to the heavy appearance of PFZs. Fortunately, the creep properties were successfully enhanced in this work through introducing mixed microstructures with both coarse and fine grains.

The effect of cyclic loading on the rubber bearing with slit damper devices based on finite element method

In this paper, slit steel rubber bearing is presented as an innovative seismic isolator device. In this type of isolator, slit steel damper is an energy dissipation device. Its advantages in comparison with that of the lead rubber bearing are its simplicity in manufacturing process and replacement of its yielding parts. Also, slit steel rubber bearing has the same ability to dissipate energy with smaller value of displacement. Using finite element method in ABAQUS software, a parametric study is done on the performance of this bearing. Three different kinds of isolator with three different values of strut width, 9, 12 and 15 mm, three values of thickness, 4, 6 and 8 mm and two steel types with different yield stress are assessed. Effects of these parameters on the performance characteristics of slit steel rubber bearing are studied. It is shown that by decreasing the thickness and strut width and by selecting the material with lower yield stress, values of effective stiffness, energy dissipation capacity and lateral force in the isolator reduce but equivalent viscous damping is not affected significantly. Thus, by choosing appropriate values for thickness, strut width and slit steel damper yield stress, an isolator with the desired behavior can be achieved. Finally, the performance of an 8-storey frame with the proposed isolator is compared with the same frame equipped with LRB. Results show that SSRB is successful in base shear reduction of structure in a different way from LRB.

Uncertainties in Finite Element Analysis of Yield Point Phenomena in Advanced High-Strength Steel Spot Welds

Effects of local plastic instabilities in the form of yield point phenomena (YPP) were investigated on local and global deformation and failure behavior of resistance spot-welded tension–shear (TS) samples made from M1700 advanced high-strength steel (AHSS) by means of finite element (FE) simulations. Material models with and without YPP were used in FE simulations, and sensitivity of results to YPP material model characteristics and failure criteria was investigated. Results from FE simulations revealed several stages of load oscillations in predicted global load–displacement curves with different amplitudes depending on material model with YPP. Results also showed the existence of heterogeneous distribution of equivalent stress in heat-affected zone (HAZ) of TS samples with strong sensitivity to the upper and the lower yield stress values in YPP material model. A stress-based failure criterion was added to the damage model to account for this stress heterogeneity, and results from this model showed that the loading and failure behavior of TS sample can significantly change from ductile to premature semi-brittle failure with significant reduction in strength of TS sample. Results from FE simulations were also compared with those from TS experiments and indicated the need for development of proper material and damage models suitable for materials with YPP.

Study on Morphology and Rheological Property of Organoclay Dispersions in Soybean Oil Fatty Acid Ethyl Ester over a Wide Temperature Range.

This work attempted to establish the relationship between the dispersion morphology and the viscous flow behavior of clay dispersions in soybean oil fatty acid ethyl ester (FAEE) at 2 and 65 °C. The clays used in this study include raw montmorillonite (Mt) and three kinds of organoclays prepared by ion exchange modification of Mt by cetyltrimethylammonium chloride (OC16), dihexadecyldimethylammonium chloride (ODC16), and trihexadecylmethylammonium chloride (OTC16), respectively. The X-ray diffraction and water contact angle results demonstrated that greater alkyl chain number of surfactants led to greater interlayer space and stronger hydrophobicity of organoclays. Due to the good affinity of the surfactant and FAEE, OC16 exhibited the most stable dispersion in FAEE between 2–65 °C, which resulted in the best flat rheological property. The molecular structures of multiple chain surfactants were quite different from that of FAEE, resulting in weak affinity between organoclays (ODC16 and OTC16) and FAEE. The sheets of ODC16 and OTC16 tended to aggregate at 2 °C, forming a gel structure, thus significantly increasing the low shear rate viscosity (LSRV) and yield stress. At 65 °C, with the expansion of FAEE and the stronger thermal motion of sheets, the dispersions of ODC16 and OTC16 were improved, destroying the original gel structure and resulting in significant decreases in LSRV and yield stress. This study confirmed that stable clay/FAEE dispersions tended to exhibit flat rheology, which could serve as a basis for the application of clay/biodiesel dispersion in deep-water drilling.

Liquid and solids separation for target resource recovery from thermal hydrolyzed sludge

This study proposed an integrated process for biogas generation and biochar production from thermal hydrolysis pretreated sludge (THP sludge). In this study, the liquid and solids fractions of THP sludge were separately processed for the first time. The liquid fraction of THP sludge (THP-L) reached the biodegradability (262.6 ± 5.1 mL CH4/g tCODfeed) on the 15th day during anaerobic treatment, while the solids fraction of THP sludge (THP-S) only contributed 31.0% to the total methane production and required more than 30 days digestion time. We investigated the feasibility to convert THP-S into biochar to realize the higher value of the solids fraction. The results prove the produced biochar can be used as slow-release fertilizer. Preliminary energy analysis was performed to evaluate the energy efficiency of the integrated approach, namely, methane generation from THP-L coupled with biochar production from THP-S. The process realized energy surplus of 0.81 MWh/tonne dry sludge. In addition, THP-L digested sludge showed better dewaterability, lower yield stress and reduced viscosity during digestion. The proposed new sludge treatment process therefore has lower operating cost and higher value returns.

Investigating the Effects of Using Plastic Waste as Fine Aggregate in Self Compacting Concrete

Self-Compacting Concrete (SCC) has properties of low yield stress, high deformability, and good segregation resistance. It is defined as fresh concrete that flows under its own weight and does not require external vibration to undergo compaction. The aim of this was to study and find the viability of replacing sand (fine aggregate) partially with recycled plastic waste (PET). Different SCC mixes were prepared with a consistent water/cementitious ratio of 0.368 with 550 kg/m3 of paste volume. The plastic waste content was varied with 0, 2.5, 5, 7.5, 10, 12.5% by weight of sand and was designated as Fine plastic waste (FPW) and was considered as the experimental parameters. The mixes were tested against their workability properties as SCC mixes, regarding tests namely L-Box test height ratio, V-funnel flow time, and slump flow diameter. Cubic compressive strength was also measured against a 28-days curing period. The experimental results indicated that plastic in small percentages could be incorporated and can successfully partially replace fine aggregate in self-compacting concrete.

Effect of particle gradation characteristics on yield stress of cemented paste backfill

Along with slurry concentration and particle density, particle size distribution (PSD) of tailings also exerts a significant influence on the yield stress of cemented paste, a non-Newtonian fluid. In this work, a paste stability coefficient (PSC) was proposed to characterize paste gradation and better reveal its connection to yield stress. This coefficient was proved beneficial to the construction of a unified rheological model, applicable to different materials in different mines, so as to promote the application of rheology in the pipeline transportation of paste. From the results, yield stress showed an exponential growth with increasing PSC, which reflected the proportion of solid particle concentration to the packing density of granular media in a unit volume of slurry, and could represent the properties of both slurry and granular media. It was found that slurry of low PSC contained extensive pores, generally around 20 μm, encouraging free flow of water, constituting a relatively low yield stress. In contrast, slurry of high PSC had a compact and quite stable honeycomb structure, with pore sizes generally < 5 μm, causing the paste to overcome a higher yield stress to flow.

Strength analysis of unidirectional composites to explain fiber bundle splitting

This paper proposes a 0° tensile strength prediction model for unidirectional composites with a low interfacial strength or low matrix yield stress applied to carbon fiber reinforced polypropylene. First, a critical dimension of broken fiber cluster in the presence of splitting is formulated using the principles of fracture mechanics. Based on the geometry of fiber packing, a relation between the rate of fiber breakage and the probability distribution of the cluster dimension is derived. Lastly, the assumption that the cross-sectional area separated by splitting sustains no load is used as a discounting factor to reduce the tensile stress in the unidirectional composites and the stress–strain relation is then predicted. The discounting factor is calculated by comparing the probability distribution for the cluster dimensions estimated from the rate of fiber breakage with that of the critical cluster dimension, both of which are functions of fiber stress. When the interfacial toughness related to the critical cluster dimension is estimated from the single-fiber pull-out test and substituted into this model, the predicted tensile strengths are in good agreement with the experimental results.

Filling Capacity Evaluation of Self-Compacting Concrete in Rock-Filled Concrete.

The good filling performance of self-compacting concrete (SCC) to pre-placed assembly of rocks is essential for quality of rock-filled concrete (RFC). In this study, a theoretical model is proposed to evaluate the filling capacity of SCC in porous media that is simplified to approximate the assembly of rocks. Numerical simulation of SCC flow in the porous media is carried out based on the computational fluid dynamics. The effects of yield stress of SCC and size and shape of grains in the porous media on the filling capacity of SCC are considered. The inclination of the free surface of the distribution of SCC at flow stoppage is defined to evaluate the filling capacity of SCC in the porous media. According to the theoretical model, the inclination is directly proportional to the yield stress of the SCC and the blocking effect of grains, while inversely proportional to the grain size. The numerical simulation provides consistent results with the theoretical model. The results suggest the use of rounded large rocks and SCC with low yield stress to ensure good quality of RFC.

Microstructure, texture, and strain-hardening behavior of extruded Mg–Gd–Zn alloys

The effect of Zn content on the microstructure, texture, mechanical properties and strain-hardening behavior of extruded Mg–2Gd–xZn (x = 0, 1, 2 and 3 wt%) sheets was investigated. Evaluation of texture revealed that while all of the alloys exhibited weak textures, the texture component was altered from a basal to a non-basal one by the addition of Zn. A typical transverse direction (TD) split texture with basal poles rotated about 40° from the normal direction (ND) toward TD was observed for the Zn-containing alloys, the effect being more pronounced at higher Zn contents. Furthermore, the Mg–2Gd–1Zn alloy exhibited the weakest texture due to solute drag imposed by co-segregation of Zn and Gd atoms at grain boundaries. Addition of Zn also resulted in a general increase in yield stress, ultimate tensile strength and elongation along the extrusion direction from 99 to 172 MPa, 178 to 263 MPa, and 25 to 35% for Mg–2Gd and Mg–2Gd–3Zn alloys, respectively. However, increasing Zn content was accompanied by an initial decrease in anisotropy of mechanical properties and strain-hardening behavior, followed by an increase at higher Zn contents. This was due to the difference of orientation of basal planes with regard to tension direction. As a result, lower yield stress, higher elongation and strain-hardening capacity was obtained along TD (with higher Schmid factor for basal slip) compared to ED. It was concluded that excellent mechanical properties and low anisotropy can be achieved in the Mg–2Gd–1Zn alloy.

The deformation and permeability of Yanji mudstone under cyclic loading and unloading

During the constructions of motorways and high-speed railway lines in the Yanji Basin, large amounts of excess mudstones due to the enormous tunnel excavations and slope cuts would be deposited as landfills. Assessing the deformation and permeability of Yanji mudstone became important for the design, construction and operation of the landfills. This paper presents an experimental study on the deformation and permeability of Yanji mudstone by carrying out a series of oedometer tests with loading/unloading cycles. The results show that the sample with a lower initial water content exhibited greater swelling deformation after inundation, a lower yield stress, greater deformation and a higher hydraulic conductivity during the loading/unloading cycles. As the number of loading/unloading cycles increased, the yield stress and accumulated plastic deformation increased, while the compression index, rebound index and hydraulic conductivity decreased. The samples became stiffer and their hydromechanical behaviour tended to be stable after three cycles. The compression curves could be divided into pre-yield and post-yield zones. The post-yield zones of compression curves and the rebound curves could be normalized into a unique line, and the pre-yield zones of the compression curves could be described as lines. Basic equations were developed to predict mudstone deformation under cyclic loading and unloading. Additionally, an empirical relationship between the hydraulic conductivity and void ratio was also proposed. The ability of the proposed methods was verified by the overall good agreement between the experimental results and predicted values.

Characterization of Ultraviolet-Cured Methacrylate Networks: From Photopolymerization to Ultimate Mechanical Properties.

In this study, the effect of different process conditions on the material properties of a single UV-cured layer of methacrylate resin, typically used in the stereolithography (SLA) process, is assessed. This simplified approach of the SLA process gives the opportunity to study the link between process conditions and mechanical properties without complicated interactions between different layers. Fourier-transform infrared analysis is performed to study the effect of light intensity, curing time, and initiator concentration on the monomer conversion. A model is developed based on the reaction kinetics of photopolymerization that describes and predicts the experimental data. The effect of curing time and light intensity on the glass-transition temperature is studied. A unique relation exists between conversion and glass-transition temperature, independent of the light intensity and curing time. Tensile tests on UV-cured resin show an increase in yield stress with increasing curing time and a linear relation between glass-transition temperature and yield stress. However, a lower light intensity leads to a different network structure characterized by a lower yield stress and glass-transition temperature. The correlations between process conditions and the mechanical properties of UV-cured methacrylate systems are established to better understand the role of the processing parameters involved in the SLA process.