Diagonal Angles Research Articles

Effect of type of internal core on the behavior of diagrid tube systems under lateral seismic loads

Diagrid structural systems have emerged as innovative and adaptable structural systems for tall buildings. These structures contain diagonal truss elements throughout the height of the structure. The present study investigated the effect of an inner steel moment frame core and an inner concentrically-braced core on a diagrid tube system under lateral seismic loading. The effect of inner cores on ductility and failure of the structures was assessed. A 36-story composite diagrid structural system with three different arrangements of diagonal angles was considered and the response spectrum analysis and nonlinear static analysis were conducted. The diagrid structures with inner cores indicated that most of the transferring lateral force in all stories is tolerated by the diagrid system; only in the last story was the shear absorbed by the internal core. Analytical results show that as the slope of braces increased, the lateral strength decreased. Diagrid structures with an inner braced core indicated greater ductility and strength than diagrid structures with inner moment frame cores. Moreover, the results indicate that the diagrid tube with an inner core produced no significant increase in ductility. To avoid premature buckling of braces, perimeter diagonal braces should be replaced with buckling-restrained elements.

THE EFFECT OF THE ANGLE AND DIMENSIONS OF A CROSS-SECTION SPECIMEN ON THE TORSIONAL STRENGTH OF AISI 1020 SQUARE STEEL SHAFT

The unknown torsional strength due to the inconsistency of the angles and dimensions of the square cross-section of AISI 1020 steel specimens in the torsion test is the problem encountered. The research method included: preparation of square AISI 1020 steel specimens measuring 6 mm x 6 mm x 160 mm, measurement of 2 diagonal angles of the cross section of the specimen and dimensions of the cross section at 5 observation points along the specimen receiving torsion loads, torsion testing of specimens, analysis of torsion test results data, and drawing conclusions. The results of the study affect the angle and dimensions of the specimen cross-section on the torsional strength of the AISI 1020 steel square shaft which has a greater value at the angles of 89o and 91o than 90o which with an angle of 89o at dimensions of 5.96 mm x 5.96 mm has a torsional strength of 412 MPa, while at an angle of 90o with dimensions of 5.96 mm x 5.96 mm it has a torsional strength of 359 MPa, and for an angle of 91o in dimensions of 5.95 mm x 5.95 mm has a torsional strength of 402 MPa. The average torsional strength is achieved in the range of 351 to 397 MPa, at an angle of 89o the torsional strength increases by 46 MPa or around 13.1 %, and at an angle of 91o the torsional strength increases by 43 MPa or around 12.3%.

Experimental investigation of flexural bond behavior of sand-coated GFRP rebar embedded in concrete

Steel rebars used in Reinforced Concrete (RC) elements may be subjected to corrosion due to aggressive environmental conditions. Rebar corrosion reduces the durability and the structural capacity of RC elements. On the other hand, since the steel rebars affect the magnetic fields, it is not preferred to be used in RC structures which is used to carry the equipment that propagate magnetic waves such as toll plazas on highways. For these reasons, the use of Fiber Reinforced Polymer (FRP) rebars is increasing, especially in RC infrastructure constructions. The objective of the present study is to investigate the bond behavior of Glass Fiber Reinforced Polymer (GFRP) rebar with a sand-coated outer surface in concrete using the arched beam test method. The concrete strength and the embedment length were chosen as variable parameters and 34 beam test specimens were tested in the laboratory. A comparative analysis of the crack patterns, the diagonal crack angles and the failure modes of the specimens is made. In addition, the experimentally determined bond-slip relationships were compared with different analytical models in the literature. Consequently, a bond-slip model, which takes into account CMR (Cosenza-Manfredi-Realfonzo) for the increasing part and mBPE (modified Bertero-Popov-Eligehausen) for the decreasing part, is proposed to be used in the numerical models of RC beams with sand-coated GFRP rebars. A prediction model for the bond strength is proposed, along with a recommendation for an upper bound value for the bond stress, which indirectly offers a minimum embedment length for a bond without slippage.

Evaluation of Steel Diagrid Structural System Under Near-Fault Earthquakes

ABSTRACTThe diagrid structural system has become popular in the construction of high-rise buildings in light of significant advantages over other structural systems. The present study explores the effects of the vertical near-fault earthquake component on the axial forces of diagonal elements in steel diagrid structures. Nonlinear time-history analysis was carried out using 11 near-fault earthquake records. A total of nine three-dimensional models of 12, 18, and 24 stories, each with diagonal angles of 45, 63.4, and 71.5 degrees, were designed and analyzed. Due to the three-dimensional modeling complexities of diagrid structures, a method was developed to transform three-dimensional models into two-dimensional ones. Finally, the scenarios with and without the vertical earthquake component were compared. It was found that the incorporation of the vertical earthquake component into the analysis of diagrid structures substantially influenced the axial forces of diagonal elements. This can affect the design load estimation of diagonal elements as the main components of a diagrid structure.

Experimental Investigation of Beams Reinforced with Carbon 2D-Netzgitterträger Reinforcement

The increasing popularity of carbon-reinforced concrete (CRC) is attributed to its exceptional tensile properties, low density, no corrosion phenomenon, and remarkable flexibility, allowing it to be easily shaped into various forms. However, there is a pressing need to explore this innovative and sustainable alternative to traditional steel reinforcement. This motivates research and investigation of the feasibility of using a special 2D Netzgitterträger (NetzGT) reinforcement system, featuring a net-shaped fabricated textile made of multiple diagonally offset rovings with overlapping edge strands, as a viable alternative to traditional steel reinforcement in concrete beams. This 2D NetzGT reinforcement system has also been transformed into a 3D configuration for the development of a hollow core slab system. It is manufactured from carbon rovings with three different diagonal angles of 50°, 60°, and 70°. Laboratory experiments were conducted to assess the mechanical behavior of beams reinforced with the 2D NetzGT reinforcement. Tensile tests on strands were also performed with an increasing number of overlapped rovings to analyze their tensile strength. Additionally, single yarn pull-out tests were also conducted to examine the influence of the roving angle on the bond strength between the carbon textile roving and the concrete matrix.

Co‐temporality and Sovremennost': Late Imperial and Early Soviet Photographs

Co‐temporality and <i>Sovremennost'</i>: Late Imperial and Early Soviet Photographs

Diagrid Core-tube Structure Seismic Performance Based on Equivalent Stiffness Ratio of Inner and Outer Tubes

To study the relationship between the stiffness ratio of the inner and outer tube of the diagrid core-tube structure of high-rise buildings and the redistribution of the storey shear force, the structural ductility, overstrength factor and the seismic performance, a total of 12 kinds of diagrid core-tube structures of equivalent stiffness ratios were established at 71°, 77° and 80° diagonal angles. Based on the static pushover analysis method, combined with the principle of capacity spectrum and demand spectrum, the characteristics and laws of the position change of the weak layer, the redistribution of the storey shear force, the shear lag effect of the bottom compression flange and the overall ductility of the structure are analyzed under the action of the frequent earthquake (70 gal), fortification earthquake (200 gal), rare earthquake (400 gal), extremely rare earthquake (510 gal) and huge earthquake (620 gal). The results show that under different earthquake actions, there is an obvious redistribution of floor shear force in the diagrid core-tube structure, and the storey shear coefficient decreases with the increase of earthquake level and equivalent stiffness ratio. The diagonal angle is the main factor affecting the location of the weak floor and the shear lag effect. The shear lag effect of the structure increases with the increase of the seismic fortification level. The structural ductility with a diagonal angle of 77° is generally optimal. When the equivalent stiffness ratio is 0.64, the structural ductility reaches the optimal value of 1.46, which is 1.1 times that of 71° and 80° diagonal angles. In the structure with the same diagonal angle, the overstrength factor increases with the increase of the equivalent stiffness ratio.

Реакции пентафенил- и пента(пара-толил)сурьмы с ферроцендикарбоновой кислотой

In reactions of pentaphenyl- and penta(para-tolyl)antimony with ferrocene dicarboxylic acid (molar ratios 1:1 and 2:1) in toluene (20 С, 24 h), hydrogen in one or two carboxylate groups is replaced with formation of tetraarylantimony ferrocene carboxylates HOOС5H4FeС5H4C(O)OSbPh4 (1), HOOС5H4FeС5H4C(O)OSbTol4 (2), Ph4SbC(O)OC5H4FeС5H4C(O)OSbPh4 (3) and p-Tol4SbC(O)OC5H4FeС5H4C(O)OSbTol4 (4), yielding up to 83 %. Compounds 1–4 have been identified by elemental analysis, IR spectroscopy, and X-ray diffraction analysis for 4. X-ray diffraction analysis of complex 4 has been performed on a D8 Quest Bruker automatic four-circle diffractometer (Mo Kα radiation, λ = 0.71073 Å, graphite monochromator ) at 293 K. Crystallographic characteristics of compound 4: monoclinic system, space group P21/c, a = 17.227(17), b = 11.064(9), c = 30.59(3) Å, β = 100.00(4) deg., V = 5742(9) Å3, Z = 4, calc = 1.440 g/cm3, 2 6.02-49.08 deg., total reflections 124343, independent reflections 9436, number of refined parameters 684, Rint = 0.1051, GOOF 1.094, R1 = 0.0536, wR2 = 0.1309, residual electron density (max/min) 0.88/1.21 e/Å3. According to the X-ray diffraction analysis data, in crystal 4 coordination of the antimony atoms is distorted octahedral due to the fact that the carboxylate ligand is a bidentate chelating ligand. The diagonal angles in the two octahedra are 146.4(2), 154.0(3), 171.0(2) and 147.4(2), 154.8(2), 166.9(2). The SbO distances are 2.296(5), 2.502(5) Å and 2.289(5), 2.453(5) Å, the SbC bonds are significantly different (2.146(7)2.166(7) and 2.123(6)2.165(7) Å). The structural organization of the crystal is mainly due to the interactions of the СН•••-type.

Mechanical properties and instability analysis of concrete specimens with horizontal holes of different diameters

Uniaxial compression tests were carried on 12 concrete specimens with six different diameter holes using a rigid test machine, and the stress–strain relationship was analyzed in different hole diameter specimens. The effects of different hole diameters on specimen compression strength, elastic modulus, and Poisson’s ratio were studied, and the failure form and instability mode of concrete specimens with holes of different diameters were evaluated. The results show that the larger the compression strength of the specimen, the larger the axial and horizontal strains. As the hole diameter increased from 0 to 50 mm, the compression strength and elastic modulus reduced. The decreasing trend slowed down, and the relationships between the hole diameter and compression strength, and elastic modulus could be represented by negative liner functions. The Poisson ratio of the specimen increased in waves with the increase in hole diameter from 0 to 50 mm. A crack in the concrete specimen with 0–20 mm diameter hole started at the upper and lower diagonal angles of the hole wall; a crack in the concrete specimen with 30–50 mm diameter hole started at the left and right parts of the hole wall. The instability mode of concrete specimens with horizontal holes of different diameters was divided into shear dislocation instability and planar splitting instability.

Синтез и строение продукта реакции пента-пара-толилсурьмы с гептафторпропил(t-бутил)дикетоном-1,3 p-Tol4Sb[t-BuC(O)СHС(О)С3F7

Penta(para-tolyl)antimony reacts with heptafluoropropyl(t-butyl)diketone-1,3 with the splitting out of toluene and formation of the substitution product p-Tol4Sb[t-BuC(O)СHС(О)С3F7] (1), yielding 82%. The compound was identified by IR spectroscopy and X-ray diffraction analysis. The X-ray analysis was performed on an automatic four-circle diffractometer D8 Quest Bruker (MoK radiation, λ = 0.71073 Å, graphite monochromator) at 293 K. Crystal size is 0.59 × 0.48 × 0.13 mm, P-1, a = 10.47(2), b = 10.94(2), c = 17.04 (3) Å, α = 73.12 (6), β = 88.94(8), γ = 89.94(8) deg., V = 1867 (7) Å3, Z = 2, ρ = 1.39 g/cm3, F(000) = 792.0, the 2θ interval is 3.89–56.999 deg., R1 = 0.2213, wR2 = 0.5429. According to the X-ray diffraction data, compound 1 is a molecular complex, in which the antimony atoms have an octahedral coordination with two oxygen atoms and two carbon atoms in the equatorial plane; the axial positions are occupied by the two remaining tolyl ligands. The CSbC axial angle is strongly distorted and is equal to 159.6 (8)°. The CSbO diagonal angles in the equatorial plane are 167.1(7)°, 166.9(7)°. The lengths of the Sb–C bonds are 2.11(2) and 2.19 (3) Å. The formation of the chain spatial structure of crystals is due to formation of bonds between the molecules involving fluorine (H∙∙∙F 2.64−2.83 Å) and carbon (C∙∙∙F 3.005 Å) atoms. Complete tables of atomic coordinates, bond lengths, and valence angles are deposited in the Cambridge Structural Data Bank (No. 2067768 (1); deposit@ccdc.cam.ac.uk or http://www.ccdc.cam.ac.uk/data_request/cif).

Enhanced forced convection heat transfer of a heat exchanger tube utilizing serrated-ring turbulators

Experiments were performed to study the thermohydraulic behaviors of heating tubes equipped with serrated-ring bundles as turbulators. Their thermohydraulic characteristics are reported in terms of Nusselt numbers (Nu) and friction factors (f) as well as performance in terms of a thermohydraulic performance index (TPI) at identical pumping power. Influences of serrated-ring diagonal angles (θ = 15°, 30°, 45° and 60°), pitch ratios (PR = 6.0, 8.0 and 12.0) and Re were examined. Various geometries of serrated-ring bundles can affect the laminar sub-layer disruption, creating a reversing flow, reconnecting the separated flow to the surface, and delaying the thermal/velocity boundary layer development. These are the most important mechanisms that lead to enhanced force convection heat transfer in a fluid flow. The heat transfer rate, friction loss and TPI increased with decreasing pitch ratio (PR) and serrated-ring diagonal angle (θ ). Heat transfer rate and friction factor were increased to 2.2 and 8.8 times that of a plain tube, respectively. Over the range investigated, the highest TPI, 1.16, was found using a serrated-ring bundle having θ = 15° and PR = 6.0 at Re = 4000.

Experiments on heat and mass transfer in enthalpy exchangers having a diagonal configuration

ABSTRACT In this study, with an aim to develop a proper effectiveness-NTU relationship of an enthalpy exchanger having a diagonal flow configuration, heat and moisture transfer experiments were conducted. Test samples having a range of diagonal angles were tested, and the effectiveness ratios between the diagonal flow and the cross-flow configuration were obtained as a function of the diagonal angle. Developed correlations of the heat, moisture, and enthalpy predicted the data within 3%. Furthermore, it was shown that the moisture transfer effectiveness was highly dependent on the relative humidity and the air temperature.

Ферроценкарбоксилат тетра(пара-толил)сурьмы. Синтез и строение

The reaction of penta(para-tolyl)antimony with ferrocene carboxylic acid in benzene (heat-ing at 80 °C for 15 minutes) leads to the formation of tetra(para-tolyl)antimony ferrocene car-boxylate (4-MeC6H4)4SbOC(O)C5H4FeC5H5 (1). Complex 1 has been characterized by IR spec-troscopy, and its structure has been established by X-ray diffraction analysis. The IR spectrum of 1, recorded on a Shimadzu IRAffinity-1S FTIR spectrometer in KBr matrix contains bands characterizing the vibrations of the Sb–C, Sb–O bonds, the CO2-group, and the ferrocene frag-ment in the range of 4000–400 cm–1. The X-ray structural analysis of the complex was carried out on an automatic four-circle D8 Quest Bruker diffractometer (МоКα-radiation, λ = 0.71073 Å, graphite monochromator) at 293 K. Crystallographic characteristics of 1: triclinic syngony, space group P-1, a = 11.02(2), b = 13.00(2), c = 13.519(19) Å,  = 68.92(5), β = 81.26(7),  = 65.71(7) deg., V = 1648(5) Å3, Z = 2, calc = 1.442 g/cm3, 2 5.674.32 deg., total reflections 96987, independent reflections 16158, number of refined parameters 392, Rint = 0.0701, GOOF 1.060, R-factors for F2 &gt; 2σ(F2) R1 = 0.0829, wR2 = 0.2390, R-factors for all reflections R1 = 0.1224, wR2 = 0.2597, residual electron density (max/min), 3.38/2.04 e/Å3. In the monomeric molecule of crystal 1 the coordination of the antimony atom is distorted octahedral, due to the fact that the carboxylate ligand is a bidentate chelating one. The diagonal angles in the octahedron are 147.5(2), 156.7(2), 167.0(2). The Sb–O(1) and Sb–O(2) distances are 2.475(6) and 2.313(5) Å, the Sb–C bonds differ significantly (2.114(6), 2.142(6), 2.152(6), 2.168(6) Å). The structural organization of the crystal is mainly due to the С–Н•••-type interactions.

Hysteretic Behavior of Reinforced Concrete Coupling Beams According to Volume Fraction of Steel Fiber

The purpose of this study was to evaluate the structural performance of steel fiber reinforced concrete (SFRC) coupling beams. Reversed cyclic loading tests were performed with full-scale specimens. The main variable for the tests was the volume fraction ratio of the steel fibers. The results showed that the maximum strength was increased by about 11% with 1% of steel fibers incorporated, and about 24% when the ratio of mixed fibers was doubled to 2%. Because numerous microcracks occurred, decreased crack width due to the bridge effect was observed with the steel fiber reinforcement. Increased diagonal tension crack angles and energy dissipation also appeared as the volume fraction of steel fibers increased. The contribution of shear to the total deformation was decreased while the contribution of rocking was increased as steel fibers were added. Considering the results of these experiments, it can be concluded that steel fiber reinforcement affects the deformation of coupling beams in various ways, and should be considered when estimating the effective stiffness of such beams when SFRC is introduced.

Lateral stiffness and preliminary design methodology of twisted diagrid tube structures

SummaryTwisted forms have been widely employed in high‐rise buildings in recent years. The diagrid structural system is particularly suitable for twisted buildings because of its large lateral stiffness and unique architectural esthetics, but little research on twisted diagrid tube structures is currently available. This paper studies the influence of diagonal angle, twist rate, aspect ratio, corner column, and plan form on the lateral stiffness of twisted diagrids, and the optimal diagonal angle range is determined. Considering the stiffness and strength criteria, the design methodology of diagonal sizes of twisted diagrids is proposed, and the methodology is validated by finite element analysis. In addition, this paper presents a novel configuration of twisted diagrid, that is, the twisted diagrid with asymmetric diagonal angles. The influence of the left‐ and right‐inclined diagonal angle on the lateral stiffness of twisted diagrids is investigated. It is found that twisted diagrid structure with asymmetric diagonal angles exhibits larger lateral stiffness than the symmetric case. The results in this paper are useful for engineers to determine the configuration and diagonal sizes of the twisted diagrid tube structures.

Collapse assessment and seismic performance factors in tall tube-in-tube diagrid buildings

Diagrid structures have been introduced as a fairly modern lateral load-resisting system in the design of high-rise buildings. In this paper, a novel diagrid system called tube-in-tube diagrid building is introduced and assessed through pushover and incremental dynamic analyses. The main objectives of this paper are to find the optimum angle of interior and exterior diagrid tube and evaluate the efficiency of diagrid core on the probability of collapse comparing to the conventional diagrid system. Finally, the seismic performance factors of the proposed system are validated according to the FEMA P695 methodology. To achieve these, 36-story diagrid buildings with various external and internal diagonal angles are designed and then 3-D nonlinear models of these structures developed in PERFORM-3D. The results show that weight of steel material highly depends on diagonal angle of exterior tube. Adding diagrid core generally increases the over-strength factor and collapse margin ratio of tall diagrid buildings confirming high seismic safety margin for tube-in-tube diagrid buildings under severe excitations. Collapse probabilities of both structural systems under MCE records are less than 10%. Finally, response modification factor of 3.0 and over-strength factor of 2.0 and 2.5 are proposed for design of typical diagrid and tube-in-tube diagrid buildings, respectively.

Evaluation of the seismic performance factors for steel diagrid structural systems using FEMA P-695 and ATC-19 procedures

The diagrid structural systems are mainly used for their structural capabilities and architectural aesthetic possibilities which are provided by the unique geometric configurations of these systems. However, the seismic performance factors of these structural systems are not yet explicitly recommended in the existing building codes. In this study, the seismic performance factors (SPFs) of 6- to 24-story steel diagrid structures are determined considering the post-buckling behavior of diagonal members in compression. Also, the effect of change in span length and the diagonal angles on the SPFs of diagrid structures is studied. The ATC-19 coefficient method is used for calculating the SPFs while FEMA P-695 approach is adopted for evaluating the accuracy of the computed factors. Also, the seismic collapse capacity of these structures considering uncertainties in ground motion, modeling, design, and test data is evaluated based on the FEMA P-695 methodology. The OpenSees software is used for modeling and performing the numerical analyses. The obtained results indicate that by increasing the height of diagrid structures, the over-strength, the response modification factor and the median collapse intensity decrease while the ductility factor increases. It is also concluded that the adjusted collapse margin ratios of the diagrid archetypes are larger than the limits suggested by FEMA P-695.

Improving the seismic performance of diagrid structures using buckling restrained braces

The seismic performance of diagrids equipped with buckling restrained braces (BRBs) is investigated. In that regard, the effects of BRBs on the seismic performance characteristics of diagrids such as response modification factor, R, overstrength factor, Ω0, ductility ratio, μ, and median collapse capacity, S^CT, are evaluated. To this end, 6 three dimensional diagrid structures with various heights and diagonal angles are modeled using OpenSees program and are equipped with BRBs in a novel arrangement. Utilizing nonlinear static analysis, the seismic performance factors of models are evaluated. Subsequently, the median collapse capacity (S^CT) of the models are determined by performing nonlinear dynamic analyses. The results indicate that using BRBs improve the seismic performance of the considered models due to accumulation of plastic damages in BRBs and a better distribution of plastic hinges over those models. The nonlinear static analyses indicate that for the original diagrid models, the response modification factor, R, ranges from 1.7–2.5, while the ductility ratio, μ, varies between 1.2 and 2.5, depending on the diagonal angles. Also, the results show that the Ω0 remains fairly constant. However, in BRB equipped diagrids, the range of R increases to 2.4–3.3, while the ductility ratio μ varies in the range 2.1–3.1. Similar to regular diagrids, Ω0 remains constant for BRB equipped models. Furthermore, the output of the dynamic analyses indicates that the S^CT, which is a function of diagonal angles and generally increases by growing the diagonal angles, could rise up to 60% for diagrids equipped with BRB.

Evaluation of Seismic Performance Factors for High-rise Steel Structures with Diagrid System

Diagrid system is a new tubular structural system in tall buildings which requires seismic performance factors (R, Ω0, Cd) for seismic design according to the loading and design codes. By considering the fact that the current codes do not include these factors, this paper aims to evaluate them based on the FEMA P695 methodology. For this purpose, five archetypes have been developed in a way that the structure story heights and span lengths are respectively equal to 4 and 6 meters; this makes the diagonal angles equal to 53.13 degrees. The response modification coefficient (R-factor) of the archetypes was calculated by the Uang method through iteration in analysis and design in OpenSees and ETABS software, respectively. Two types of analysis were carried out: non-linear static analysis (pushover analysis) and non-linear incremental dynamic analysis (IDA); the first evaluates ductility, μT, and over-strength factors, Ω, and the second evaluates “collapse margin ratio (CMR)”. At the end, computed “adjusted collapse margin ratio (ACMR)” was controlled by acceptable values of ACMR in the FEMA P695. Based on the results, the values of R-factor, over-strength factor, Ω0, and deflection amplification factor, Cd, are proposed to be 2.5, 2.0 and 2.5, respectively.

Evaluation of the Deterioration of the Mechanical Properties of Poly(lactic acid) Structures Fabricated by a Fused Filament Fabrication 3D Printer

A fused filament fabrication (FFF) 3D printer is a simple device capable of manufacturing three-dimensional structures in a series of easy steps. Commercial-level FFF 3D printers have spread rapidly in many fields in recent years. Poly(lactic acid) (PLA) is a biodegradable thermoplastic polymer used as a typical printing medium for FFF 3D printers. The FFF printer constructs an object with melted polymer extruded from a tiny scanning nozzle. The mechanical properties of FFF 3D structures printed with different scan patterns can therefore vary in accordance with the directions from which forces act upon them. The nozzle scan pattern also influences the deterioration of the mechanical properties of the structures in accordance with the degradation caused by the hydrolysis of PLA. In this study we conducted tensile tests to evaluate the strength characteristics of 3D printed test pieces formed from PLA using four different scan patterns: parallel, vertical, parallel-and-vertical, and cross-hatched at opposing diagonal angles to the tensile direction. We also formed test pieces by an injection molding method using the same material, for further comparison. We evaluated the deterioration of the test pieces after immersing them in saline for certain periods. After the test pieces formed by different nozzle scan patterns were immersed, they exhibited differences in the rates by which their maximum tensile stresses deteriorated and their masses increased through water uptake. The influences of the scan patterns could be classified into two types: the unidirectional scan pattern influence and bidirectional scan pattern influence. The data obtained in this research will be applied to structural design when the FFF 3D printer is employed for the fabrication of structures with PLA filament.