THE INCREASING USE OF STAINLESS STEEL IN CONSTRUCTION HAS LED TO THE NEED OF DEVELOPINGRESISTANCE MODELS FOR STRUCTURAL ELEMENTS MADE OF THIS MATERIAL. UNLIKE CARBON STEELS, STAINLESS STEEL ALLOYS EXHIBIT STRESS-STRAIN CURVES WITH A PRONOUNCED STRAIN HARDENING CAPACITY AND REASONABLE DUCTILITY THAT SHOULD BE CONSIDERED IN THE DESIGN. THIS DIFFERENCE IN BEHAVIOR MAKES THE FORMULATIONS USED FOR CARBON STEEL CONSERVATIVE WHEN DESIGNING WITH STAINLESS STEEL. THEREFORE, THIS PAPER PRESENTS A COMPARATIVE ANALYSIS OFRESISTANCE MODELS FOR SLENDER AUSTENITIC STAINLESS-STEELBEAMS SUBJECT TO CONCENTRATED LOADS. FIRST, THE FAILURE MECHANISMS OF STAINLESS-STEELBEAMS ARE PRESENTED USING A NONLINEAR FINITE ELEMENT MODEL. FROM THIS VALIDATED NUMERICAL MODEL, A DATABASE OBTAINED FROM A PARAMETRIC ANALYSIS THAT COVERS A WIDE RANGE OF GEOMETRIES IS PRESENTED. SUBSEQUENTLY, THIS DATABASE IS USED TO PERFORM A COMPARISON BETWEEN VARIOUS RESISTANCE MODELS AVAILABLE IN THE LITERATURE. THESE MODELS CORRESPOND TO BOTH INTERNATIONAL DESIGN CODES AND MODELS OBTAINED THROUGH MACHINE LEARNING. FINALLY, THE NUMERICAL RESULTS SHOW CONSIDERABLE IMPROVEMENT IN THE PREDICTED ULTIMATE RESISTANCES FOR SLENDER STAINLESS STEEL PLATE GIRDERS SUBJECTED TO PATCH LOADING.

ARTIFICIAL INTELLIGENCE (AI) HAS BECOME A RELIABLE TOOL FOR THE SOLUTION OF STRUCTURAL ENGINEERING PROBLEMS. THIS PAPER AIMS AT DEVELOPING PREDICTION MODELS FOR THE BEHAVIOR OF EXTRUDED ALUMINUM BEAMS UNDER PATCH LOADING VIA SYMBOLIC REGRESSION (SR) AND ARTIFICIAL NEURAL NETWORKS (ANN). THE MODELS ARE CONSTRUCTED EMPLOYING AN EXTENSIVE DATASET CALCULATED NUMERICALLY THROUGH NONLINEAR FINITE ELEMENT ANALYSIS. THIS DATASET COVERS A WIDE RANGE OF GEOMETRIC PARAMETERS AND CONSIDERS ALUMINUM ALLOYS WITH DIFFERENT STRAIN HARDENING CHARACTERISTICS. EXPLICIT FORMULATIONS FOR THE RESISTANCE OF EXTRUDED ALUMINUM BEAMS TO PATCH LOADING ARE DEVELOPED BY FITTING THIS DATASET USING SR AND ANN, THE RESULTS ARE COMPARED WITH THOSE OF THE RESISTANCE MODEL IN THE EC9:1-1. FINALLY, THE PERFORMANCE OF THE PROPOSED AI MODELS IS ALSO EVALUATED. RESULTS CONFIRMED THE SUPERIOR ACCURACY OF THE PROPOSED MODELS.

CURRENTLY, THERE ARE DIFFERENT OPTIONS TO INCREASE THE ULTIMATE RESISTANCE OF PLATE GIRDERS SUBJECTED TO PATCH LOADING. SOME OF THESE ALTERNATIVES INCLUDE THE USE OF CLOSELY SPACED TRANSVERSE STIFFENERS AND THE USE OF LONGITUDINAL STIFFENERS. NEVERTHELESS, RECENT INVESTIGATIONS HAVE DEMONSTRATED THAT THE RESISTANCE IS ALSO IMPROVED BY USING DELTA STIFFENERS, WHICH ARE OBTAINED BY WELDING TWO PLATES BETWEEN THE WEB PLATE AND THE LOADED FLANGE. THIS PAPER AIMS AT STUDYING THE ELASTIC BUCKLING BEHAVIOR OF SLENDER PLATE GIRDERS DESIGNED FOLLOWING AASHTO NORMS WITH DELTA STIFFENERS SUBJECTED TO PATCH LOADING. THE RESEARCH IS CARRIED OUT BY MEANS OF EIGENVALUE ANALYSIS USING THE FINITE ELEMENT METHOD. A PARAMETRIC STUDY IS PERFORMED TO EVALUATE THE INFLUENCE OF VARIOUS GEOMETRICAL PARAMETERS ON THE BUCKLING COEFFICIENT OF THE GIRDER. FINALLY, DESIGN RECOMMENDATIONS ARE SUGGESTED BASED ON THE OBTAINED RESULTS.

IN STEEL BRIDGE GIRDERS, LONGITUDINAL STIFFENING IS PRIMARILY EMPLOYED TO INCREASE THE FLEXURAL AND SHEAR RESISTANCE. INTERNATIONAL DESIGN CODES RECOMMEND THE USE OF LONGITUDINAL STIFFENERS AT ONE-FIFTH OF THE GIRDER DEPTH AS THE OPTIMUM POSITION FOR FLEXURAL RESISTANCE, MEANWHILE EXPERIMENTAL AND NUMERICAL RESULTS FOUND IN THE LITERATURE INDICATE THAT THE OPTIMUM POSITION FOR PATCH LOADING RESISTANCE IS DIFFERENT. A CHECK FOR PATCH LOADING IS REQUIRED FOR STEEL BRIDGES ERECTED BY INCREMENTAL LAUNCHING AT CONSTRUCTION STAGE, SINCE BENDING AND SHEAR GOVERN THE IN-SERVICE GIRDERS BEHAVIOR. THEREFORE TO PLACE A LONGITUDINAL STIFFENER ONLY FOR PATCH LOADING MAY BE UNECONOMICAL. THIS PAPER IS AIMED AT INVESTIGATING THE BEHAVIOR OF LONGITUDINALLY STEEL I-GIRDERS WITH A LONGITUDINAL STIFFENER PLACED AT ONE-FIFTH OF THE GIRDER DEPTH SUBJECTED TO PATCH LOADING. NONLINEAR FINITE ELEMENT ANALYSES ARE CONDUCTED IN ORDER TO INVESTIGATE THE INTERACTION BETWEEN GEOMETRIC PARAMETERS INFLUENCING THE RESISTANCE TO PATCH LOADING. FINALLY, DESIGN RECOMMENDATIONS FOR LONGITUDINALLY STIFFENED I-GIRDERS ARE PRESENTED.

THIS PAPER AIMS AT INVESTIGATING THE FAILURE RESPONSE OF EXPANDED METAL MESHES SUBJECT TO TRANSVERSAL IMPACT. FIRSTLY, THE STUDY IS PERFORMED THROUGH EXPLICIT NONLINEAR FINITE ELEMENT ANALYSIS, IN WHICH A NUMERICAL MODEL IS DEVELOPED TO DETERMINE THE IMPACT PERFORMANCE AND FAILURE MODE OF EXPANDED METAL MESHES. THEREAFTER, THE EFFECT OF EXPANDED METAL CELL GEOMETRIES, IMPACT MASS AND VELOCITY ON THE STRUCTURAL RESPONSE OF THE MESHES IS ANALYZED. THEN THE PERFORATION RESISTANCE OF THE IMPACTED MESHES IS ASSESSED AND ANALYZED BY MEANS OF VULNERABILITY CURVES FOR VARIOUS EXPANDED METAL GEOMETRIES SUBJECT TO TRANSVERSAL IMPACT. THE EXTENT OF DAMAGE IN THE MESHES IS ALSO EVALUATED, AND THE MAXIMUM DISPLACEMENTS ACHIEVED IN EACH IMPACT SCENARIO IS QUANTIFIED. AT THE END, IT IS DEMONSTRATED THAT THE PERFORATION PERFORMANCE OF THE MESHES DEPENDS ON THE EXPANDED METAL CELL DIMENSIONS EXPRESSED AS A COMBINATION OF THE STRAND CROSS-SECTION AND MAJOR AXIS LENGTH. FINALLY, THE RESULTS ALSO SHOW THE FEASIBILITY OF USING EXPANDED METAL MESHES TO PROTECT STRUCTURES IMPACTED BY FLYING DEBRIS

THIS STUDY EXAMINES THE FLEXURAL PERFORMANCE OF SIX 9-M FULL-SCALE TWO-SPAN NAIL-LAMINATED TIMBER CONCRETE (NLTC) COMPOSITE SLABS. THE SLABS WERE MADE WITH LUMBER BEAMS EDGE-JOINED WITH DOUBLE NAILING, END-JOINED WITH BUTT JOINTS, AND THE REINFORCED CONCRETE TOPPING CONNECTED WITH A SET OF NOTCHES, INCLINED SCREWS, OR A COMBINATION OF BOTH. THE MULTI-SPAN CONFIGURATION OF SLABS REDUCES THEIR DEFLECTIONS SIMPLY AND EFFECTIVELY. FIVEPOINT MONOTONIC BENDING TESTS WERE CONSIDERED FOR ALL SLABS. BEFORE FULL-SCALE SLABS, COMPRESSIVE AND TENSILE PULLOUT TESTS OF TIMBER-CONCRETE COMPOSITE (TCC) SHEAR CONNECTIONS WERE PERFORMED, INCLUDING NOTCHES AND INCLINED SCREWS. TENSILE PULL-OUT TESTS OF SHEAR CONNECTIONS WERE ALSO INCLUDED TO EMULATE THE NEGATIVE BENDING MOMENTS THAT OCCUR IN THE MIDDLE OF THE SLABS. FAILURE MODES, LOAD-MID-SPAN DEFLECTION RELATION, BENDING STIFFNESS, AND TIMBER-CONCRETE SLIP WERE EVALUATED FOR ALL SLABS. A DETAILED 3D MICRO-FINITE ELEMENT (FE) MODEL OF THE SHEAR CONNECTIONS WAS BUILT IN ANSYS SOFTWARE, WHEREAS A MACRO-FE MODEL OF NLTC SLABS WAS MADE IN SAP2000, DEMONSTRATING A GOOD FIT FOR THE TIMBER-CONCRETE INTERACTION AND THE LOAD-CARRYING CAPACITY OF THE COMPOSITE SLAB AT THE SERVICEABILITY RANGE. MOREOVER, AN ANALYTICAL ELASTIC TCC BEAM WITH THE GIRHAMMAR METHOD WAS ASSESSED AND DEMONSTRATED AS MORE PRECISE THAN THE TRADITIONAL GAMMA-METHOD. FINALLY, AN ACCURATE PREDICTION OF THE NUMERICAL AND ANALYTICAL (GIRHAMMAR) MODELS FOR THE BENDING STIFFNESS AT SERVICE LOADS UP TO 30% OF CAPACITY IS OBSERVED, WITH ERRORS IN A RANGE OF 2-23% AND 9-74%, RESPECTIVELY.

OVER THE LAST DECADES, IN SPITE OF ITS COST, THE USE OF STAINLESS ALLOYS HAS GROWN SIGNIFICANTLY OWING TO ENVIRONMENTAL CONCERNS, LOW MAINTENANCE, AND HIGH CORROSION RESISTANCE. THIS PAPER IS AIMED AT DEVELOPING A PREDICTION MODEL FOR THE RESISTANCE OF SLENDER AUSTENITIC STAINLESS STEEL PLATE GIRDER SUBJECTED TO PATCH LOADING USING A MACHINE LEARNING BASED APPROACH. FIRSTLY, THE STUDY IS CONDUCTED THROUGH GEOMETRICALLY AND MATERIALLY NONLINEAR WITH IMPERFECTION ANALYSES (GMNIA). THE NUMERICAL METHODOLOGY IS VALIDATED BY COMPARISON WITH EXPERIMENTAL RESULTS AVAILABLE IN THE LITERATURE. SECONDLY, AN EXTENSIVE PARAMETRIC ANALYSIS COVERING A WIDE RANGE OF GIRDER GEOMETRIES IS PERFORMED. A NUMERICAL DATABASE RESULTING FROM THE PARAMETRIC ANALYSIS IS FITTED USING SYMBOLIC REGRESSION AND A RESISTANCE MODEL IS ATTAINED. FINALLY, THE ACCURACY OF THE PREDICTION MODEL IS EVALUATED BY COMPARISON OF THE PREDICTED RESISTANCES WITH VALUES COMPUTED NUMERICALLY, AND RESISTANCES PREDICTED USING AVAILABLE FORMULAE FROM THE LITERATURE.

DURING CERTAIN MAINTENANCE OR CAPACITY-BUILDING TASKS OF OPERATING REFINERY EQUIPMENT (E.G. REACTORS, REGENERATORS, ETC.), IT IS OFTEN NECESSARY TO REMOVE AND SUBSEQUENTLY HOIST THE UPPER HEMISPHERICAL HEAD OF THE EQUIPMENT. IN THE LIFTING PHASE, THE HEAD MUST BE MAINTAINED IN SUCH A WAY THAT THE WELDING BETWEEN IT AND THE BODY OF THE VESSEL IS FEASIBLE TO PERFORM. THIS WELDING CAN BE PERFORMED IF THE DEFORMATIONS IN THE PERIPHERY OF THE HEAD BASE ARE SMALL, OTHERWISE ADDITIONAL ADJUSTMENT PROCESSES MUST BE CARRIED OUT THAT CAN DELAY THE COMMISSIONING OF THE EQUIPMENT INDUCING ECONOMIC LOSSES. IN THE PLANNING OF THE HOISTING, THE DETERMINATION OF THE POSITION AND THE NUMBER OF EARS TO BE USED IS IMPORTANT, THIS WILL AFFECT THE DISTRIBUTION OF THE LOADS AND CONSEQUENTLY THE DEFORMATIONS THAT THE PERIPHERY OF THE HEAD WILL EXPERIENCE. THIS PAPER PRESENTS A FINITE ELEMENT ANALYSIS OF A HEMISPHERIC HEAD OF A REGENERATOR DURING THE LIFTING PROCESS. THE HEAD IS SUBJECTED TO THE ACTION OF GRAVITY LOADS AND EXTERNAL LOADS PRODUCED BY STRUCTURAL ELEMENTS CONNECTED TO THE HEAD. IN THE LIFTING PROCESS, THE HEAD IS ALSO SUBJECTED TO THE TENSION FORCES GENERATED BY THE LIFTING CABLES. FROM THE NUMERICAL MODEL, A PARAMETRIC STUDY WAS CARRIED OUT TO DETERMINE THE OPTIMAL ARRANGEMENT OF THE HOISTING CLIPS TAKING INTO ACCOUNT THE DEFORMATIONS IN THE PERIPHERY OF THE HEAD BASE, IN ORDER TO GUARANTEE THE WELDING PROCESS WITH THE BODY OF THE VESSEL. ADDITIONALLY, THE USE OF A STIFFENING RING AND ITS INFLUENCE ON THE DEFORMATION OF THE HEAD WERE ANALYZED.

RECENT INVESTIGATIONS RELATED TO PLATE GIRDERS DESIGN HAVE DEMONSTRATED THAT IS POS-SIBLE TO INCREASE THE FLEXURAL AND SHEAR RESISTANCE BY USING DELTA HOLLOW FLANGE GIRDERS. THIS TYPE OF REINFORCEMENT ALSO INCREASES THE TORSIONAL RIGIDITY OF THE PLATE GIRDER REDUCING LATERAL DEFOR-MATION. HOWEVER, THE IMPACT OF DELTA HOLLOW FLANGE GIRDERS SUBJECTED TO PATCH LOADING HAS RE-CEIVED LITTLE ATTENTION. THEREFORE, THIS PAPER AIMS AT STUDYING THE POSTBUCKLING BEHAVIOUR AND COM-PARING THE PATCH LOADING RESISTANCE OF LONGITUDINALLY STIFFENED AND DELTA HOLLOW FLANGE GIRDERS, EVALUATING THE INFLUENCE OF DIFFERENT GEOMETRICAL PARAMETERS SUCH AS THE PANEL ASPECT RATIO, THE PATCH LOADING LENGTH AND THE POSITION OF THE LONGITUDINAL STIFFENER. TO THIS PURPOSE, A NONLINEAR FINITE ELEMENT MODEL WAS DEVELOPED CONSIDERING GEOMETRICAL AND MATERIAL IMPERFECTIONS. THE COMPUTED ULTIMATE RESISTANCES ARE VALIDATED AGAINST EXPERIMENTAL RESULTS FOUND IN THE LITERATURE. BASED ON THE RESULTS, DESIGN RECOMMENDATIONS ARE PRESENTED FOR HOLLOW FLANGE GIRDERS UNDER PATCH LOADING.

THIS PAPER PRESENTS A NUMERICAL INVESTIGATION ON THE DESIGN RESISTANCE OF EXTRUDED ALUMINUM BEAMS SUBJECTED TO CONCENTRATED LOADS. THE STUDY IS CONDUCTED THROUGH NONLINEAR FINITE ELEMENT ANALYSIS CONSIDERING LARGE DISPLACEMENTS, INITIAL IMPERFECTION, AND TAKING INTO ACCOUNT THE STRAIN HARDENING CHARACTERISTICS OF COMMON ALUMINUM ALLOYS. THE NUMERICAL MODEL IS VALIDATED AGAINST EXPERIMENTAL WORKS TAKEN FROM THE LITERATURE. THEREAFTER, AN EXTENSIVE PARAMETRIC STUDY IS CARRIED OUT COVERING A WIDE RANGE OF BEAM GEOMETRIES AND SLENDERNESS RATIOS. RESISTANCES COMPUTED NUMERICALLY ARE COMPARED WITH THOSE CALCULATED USING THE CURRENT DESIGN PROVISIONS IN THE EC9 FOR ALUMINUM BEAMS SUBJECT TO CONCENTRATED LOADS, INDICATING THAT THE EC9 PROVISIONS UNDERESTIMATE THE RESISTANCES. THEN, A NEW RESISTANCE FUNCTION IS CALIBRATED PERFORMING A STATISTICAL EVALUATION OF EXPERIMENTAL AND NUMERICAL RESULTS. THE RELIABILITY OF THE RECALIBRATED RESISTANCE FUNCTION IS ASSESSED ACCORDING TO EN 1990, THE RESULTS SHOW IMPROVEMENTS IN THE PREDICTED RESISTANCES. FINALLY, THE USE OF MORE ACCURATE STRUCTURAL DESIGN PROVISIONS ENHANCES THE POSSIBILITY OF HIGHER ECONOMIC BENEFITS, AND BY USING LESS MATERIAL, THE CARBON FOOTPRINT ORIGINATED FROM ALUMINUM PRODUCTION CAN BE REDUCED.

IN THIS PAPER, THE BEHAVIOR OF A TUNED MASS DAMPER (TMD), TO TORSIONALLY CONTROL A LINEAR STRUCTURE SUBJECTED TO SEISMIC EXCITATIONS, IS INVESTIGATED. THE DYNAMIC SYSTEM IS ANALYZED TAKING INTO ACCOUNT LATERAL-TORSIONAL COUPLING, SOIL?STRUCTURE INTERACTION, AND THE ROTATIONAL COMPONENTS OF THE FOUNDATION MOTION. THE SYSTEM MODEL CONSISTS OF AN ASYMMETRICAL STRUCTURE, FOUNDED ON A SOIL MODELED AS A HOMOGENEOUS SEMI-SPACE. A STATIONARY STOCHASTIC ANALYSIS IS PERFORMED IN THE TIME DOMAIN, AND A DOUBLE CLOUGH-PENZIEN FILTER OF BROAD FREQUENCY CONTENT IS USED TO DEFINE THE RANDOM PROCESS FOR THE X AND Y DIRECTIONS. THE TORSIONAL BALANCE CRITERION IS EMPLOYED FOR THE OPTIMIZATION OF THE TMD DESIGN PARAMETERS. THE INFLUENCE OF THE PLAN STATIC ECCENTRICITY OVER OPTIMUM TMD PARAMETERS BEHAVIOR IS ALSO ADDRESSED, TAKING INTO ACCOUNT THE FIXED BASE PERIOD, FLEXIBLE PERIOD, TORSIONAL FREQUENCY RATIO, AND SOIL TYPE. COMPLIANCE WITH THE TORSIONAL BALANCE IS VERIFIED. THE RESULTS SHOW THAT THE INCLUSION OF THE SOIL ROTATIONAL COMPONENT HAS A NOTORIOUS INFLUENCE ON THE OPTIMUM TMD PARAMETERS. MOREOVER, TORSIONALLY FLEXIBLE STRUCTURES FOUNDED ON SOFT AND MEDIUM SOIL SHOW SIGNIFICANT INFLUENCE ON THE TORSIONAL BALANCE. FINALLY, A TRANSITORY RESPONSE ANALYSIS IS CARRIED OUT FOR A 15-STORY MODEL, SUBJECTED TO AN ARTIFICIAL BIDIRECTIONAL EARTHQUAKE WITH A BROADBAND FREQUENCY CONTENT. THE MULTISTORY MODEL RESPONSE VALIDATES THE RESULTS DERIVED FROM THE STOCHASTIC ANALYSIS.

3D-PRINTED CONSTRUCTION ALLOWS ELABORATING BUILDING ELEMENTS WITH DIVERSE SHAPES THAT ARE DIGITALLY CONTROLLED. THIS PAPER EXPOSES THE MODELING OF 3D-PRINTED CURVED WALLS THROUGH PARAMETRIC PROGRAMMING IN BUILDING INFORMATION MODELING (BIM) IN ORDER TO SUPPORT A COST-EFFICIENT BUILDING DESIGN. THE ADVANTAGE OF USING CURVED WALLS IS BASED ON THE POSSIBILITY OF REDUCING THEIR THICKNESS WITH RESPECT TO STRAIGHT WALLS OF SIMILAR LENGTH GIVEN THEIR HIGHER RESISTANCE TO OVERTURNING FORCES. THE PROGRAMMING DEVELOPED HERE CAN PROPOSE A CONSIDERABLE SET OF SOLUTIONS USING CURVED WALLS FOR A RECTANGULAR ENCLOSURE OF DIMENSIONS GIVEN BY THE USER. A CASE STUDY FOR A VEHICLE SALE PAVILION IS SHOWN, FOR WHICH A SET OF 1,600 SOLUTIONS WITH CURVED WALLS OF DIFFERENT CURVATURE ANGLES AND LENGTHS IS GENERATED AND SUBSEQUENTLY ANALYZED. FROM THIS ANALYSIS, THOSE MODELS WITH LOWER MATERIAL CONSUMPTION AND EXECUTION TIME ARE SELECTED TO BE MORE THOROUGHLY STUDIED IN THE DESIGN PROCESS. THUS, A NOVEL STRATEGY IS PROVIDED TO RESEARCHERS AND PRACTITIONERS FOR DEVELOPING MORE EFFICIENT AND EXPRESSIVE BUILDING DESIGNS BASED ON 3D-PRINTED CONSTRUCTION. THE MOST EFFICIENT SOLUTION IDENTIFIED IN THE EXAMPLE REDUCES MATERIAL CONSUMPTION BY 61%, WITH AN ESTIMATED COST SAVING OF 53%.

THIS PAPER AIMS AT INVESTIGATING THE PATCH LOADING RESISTANCE OF STEEL PLATE GIRDERS WITH TRIANGULAR CELL FLANGES. THIS GEOMETRICAL ARRANGEMENT INCREASES CONSIDERABLY THE RESISTANCE OF THE WEB PLATES WHEN SUBJECTED TO CONCENTRATED LOADING. IN THIS STUDY, THE PATCH LOADING RESISTANCE IS STUDIED BY MEANS OF GMNI- ANALYSES CONSIDERING LARGE DISPLACEMENTS, ELASTOPLASTIC MATERIAL BEHAVIOR, INITIAL GEOMETRIC IMPERFECTIONS, AND AN ASSUMED PATTERN OF RESIDUAL STRESS DISTRIBUTION. THE NUMERICAL MODEL IS VALIDATED AGAINST EXPERIMENTAL RESULTS TAKEN FROM THE LITERATURE. THEREAFTER, A PARAMETRIC STUDY IS CONDUCTED IN ORDER TO INVESTIGATE THE INFLUENCE OF VARIOUS GEOMETRIC PARAMETERS SUCH AS THE LOCATION IN THE WEB AND FLANGE AS WELL AS THE THICKNESS OF THE PLATES THAT FORMS THE TRIANGULAR CELLS, AND THE PANEL ASPECT RATIO ON THE RESISTANCE OF THE STIFFENED GIRDERS. A DESIGN PROPOSAL IS ALSO PRESENTED FOLLOWING THE GUIDELINE IN THE EC3:1?5. THIS PROPOSAL TAKES INTO ACCOUNT THE INFLUENCE OF THE STIFFENING EFFECT PROVIDED BY THE TRIANGULAR CELL FLANGES. THE RESULTS SHOW THAT THE USE OF TRIANGULAR CELL FLANGES ENHANCES THE RESISTANCE OF STEEL PLATE GIRDERS TO PATCH LOADING.

THIS PAPER IS AIMED AT INVESTIGATING THE EFFECT OF MULTIPLE LONGITUDINAL STIFFENERS ON THE PATCH LOADING RESISTANCE OF SLENDER STEEL PLATE GIRDERS. FIRSTLY, A NUMERICAL STUDY IS CONDUCTED THROUGH GEOMETRICALLY AND MATERIALLY NONLINEAR ANALYSIS WITH IMPERFECTIONS INCLUDED (GMNIA), THE MODEL IS VALIDATED WITH EXPERIMENTAL RESULTS TAKEN FROM THE LITERATURE. THE STRUCTURAL RESPONSES OF GIRDERS WITH MULTIPLE LONGITUDINAL STIFFENERS ARE COMPARED TO THE ONE OF GIRDERS WITH A SINGLE LONGITUDINAL STIFFENER. THEREAFTER, A PATCH LOADING RESISTANCE MODEL IS DEVELOPED THROUGH MACHINE LEARNING (ML) USING SYMBOLIC REGRESSION (SR). AN EXTENSIVE NUMERICAL DATASET COVERING A WIDE RANGE OF BRIDGE GIRDER GEOMETRIES IS EMPLOYED TO FIT THE RESISTANCE MODEL USING SR. FINALLY, THE PERFORMANCE OF THE SR PREDICTION MODEL IS EVALUATED BY COMPARISON OF THE RESISTANCES PREDICTED USING AVAILABLE FORMULAE FROM THE LITERATURE.

THIS PAPER PRESENTS A NUMERICAL INVESTIGATION ON THE PATCH LOADING RESISTANCE OF SLENDER AUSTENITIC STAINLESS STEEL PLATE GIRDERS. CURRENT DESIGN PROVISIONS FOR THE RESISTANCE TO PATCH LOADING OF STAINLESS STEEL GIRDERS ARE BASED ON THE PLASTIC COLLAPSE MECHANISM OBSERVED IN EXPERIMENTAL AND NUMERICAL STUDIES CONDUCTED FOR CARBON STEEL GIRDERS, DISREGARDING THE STRAIN HARDENING CAPACITIES OF STAINLESS STEEL. AT PRESENT, STRENGTH-CURVES APPROACHES ARE USED WITHIN EUROPEAN STANDARDS TO DEAL WITH STABILITY PROBLEMS IN STEEL PLATED STRUCTURAL ELEMENTS. IN THIS REGARD, THREE PARAMETERS REQUIRE SPECIAL ATTENTION: THE YIELD LOAD FOR PLASTIC RESISTANCE, THE RESISTANCE FUNCTION DEPENDING ON ELEMENT SLENDERNESS, AND THE ELASTIC BUCKLING LOAD. IN THIS PAPER, AN EXPERIMENTAL DATASET IS FIRSTLY COLLECTED FROM THE LITERATURE FOR COMPARATIVE ANALYSIS. SUBSEQUENTLY, AN EXTENSIVE PARAMETRIC STUDY IS CONDUCTED THROUGH NONLINEAR FINITE ELEMENT ANALYSES COVERING A WIDE RANGE OF SLENDER STAINLESS STEEL I-GIRDER SECTIONS. THEN, A RESISTANCE FUNCTION IS CALIBRATED THROUGHOUT A STATISTICAL EVALUATION OF EXPERIMENTAL AND NUMERICAL RESULTS. FINALLY, THE RESULTS SHOW SIGNIFICANT IMPROVEMENTS IN THE PREDICTED PATCH LOADING RESISTANCES OF SLENDER STAINLESS STEEL I-GIRDERS.

THIS PAPER PRESENTS A NUMERICAL STUDY ON THE EFFECT OF VARIOUS STIFFENING STRATEGIES EMPLOYED TO IMPROVE THE ULTIMATE STRENGTH OF PERFORATED PLATE GIRDERS WEBS SUBJECT TO SHEAR LOADING. THE POSTBUCKLING BEHAVIOR OF THE PLATE GIRDERS WITH PERFORATIONS STIFFENED WITH VARIOUS TYPES OF STIFFENER UNDER SHEAR FORCES IS INVESTIGATED BY MEANS OF NONLINEAR FINITE ELEMENT ANALYSIS. THEN, A COMPARATIVE STUDY IS CONDUCTED TO ESTABLISH THE BEST STIFF-ENER CONFIGURATION (LONGITUDINAL, AND CIRCULAR) ACCORDING TO THE GIRDER AND OPENING DIMENSIONS. MOREOVER, UL-TIMATE STRENGTH VALUES ARE VALIDATED AGAINST EXPERIMENTAL RESULTS FOUND IN THE LITERATURE. THEN, A PARAMETRIC ANALYSIS IS PERFORMED IN ORDER TO STUDY THE STRUCTURAL BEHAVIOR AND ULTIMATE STRENGTH BY VARYING SOME KEY FAC-TORS SUCH AS THE WEB SLENDERNESS, PANEL ASPECT RATIO, OPENING SIZE AND STIFFENER PROPERTIES. FINALLY, SOME REC-OMMENDATIONS TO ENHANCE THE ULTIMATE STRENGTH OF THIS TYPE OF GIRDERS ARE PRESENTED.

THIS PAPER AIMS TO INVESTIGATE THE EFFECT OF THE VARIABILITY IN THE MECHANICAL AND CROSS-SECTION PROPERTIES OF CHILEAN RADIATA PINE ON THE LATERAL BUCKLING STRENGTH OF SLENDER WOODEN BEAMS. THE STUDY IS CONDUCTED NUMERICALLY THROUGH FINITE ELEMENT MODELING AND USING LINEAR EIGENVALUE ANALYSIS. THE NUMERICAL MODEL IS VALIDATED USING EXPERIMENTAL RESULTS AVAILABLE IN THE LITERATURE. TWO APPROACHES ARE EMPLOYED IN THE ANALYSIS, FIRSTLY A DETERMINISTIC APPROACH USING DESIGN OF EXPERIMENTS (DOE) TECHNIQUES TO ESTABLISH THE RELEVANCE OF THE PARAMETERS, AND SECONDLY A STOCHASTIC ONE, THROUGH MONTE-CARLO SIMULATION TO INVESTIGATE THE IMPACT OF EACH PARAMETER ON THE LATERAL BUCKLING RESISTANCE. VARIOUS DISTRIBUTION FUNCTIONS ARE CONSIDERED TO INVESTIGATE THE EFFECT OF UNCERTAINTIES IN THE MATERIAL PARAMETERS AND THEIR IMPACT ON THE CRITICAL BUCKLING MOMENTS. MOREOVER, SOBOL INDICES INDICATED THAT FROM THE TOTAL VARIABILITY OF THE DISTRIBUTION OF THE CRITICAL MOMENT, AN AVERAGE OF 50% OF THE VARIABILITY IS ATTRIBUTED TO THE SHEAR MODULUS ?LR, 37% TO THE LONGITUDINAL ELASTIC MODULUS ??, AND A NEGLIGIBLE PERCENTAGE OF THE GRAIN ANGLE ?.

THE VIRTUAL ROTOR KIT (VRK) PROJECT; IS A LIGHTWEIGHT AND STANDALONE APPLICATION DEVELOPED IN RESPONSE TO THE CHALLENGES POSED BY THE COVID-19 OUTBREAK IN THE FIELD OF ROTATING MACHINERY DYNAMICS. THIS ALTERNATIVE EMULATES A ROTOR TEST RIG, ENABLING VIRTUAL BALANCING TESTS ON A SINGLE-PLANE ROTOR AND OFFERING STUDENTS A COMPREHENSIVE LEARNING EXPERIENCE THAT SIMULATES ON-SITE BALANCING. THE VIRTUAL ROTOR KIT UTILIZES A THREE-DIMENSIONAL MODEL BASED ON A WELL-KNOWN ROTOR TEST RIG WIDELY USED IN EDUCATIONAL AND RESEARCH SETTINGS. TO SIMULATE THE DYNAMICS OF THE ROTOR TEST RIG, THE APPLICATION EMPLOYS PYCHRONO, A DEDICATED PYTHON LIBRARY THAT WRAPS CHRONO, A VALIDATED OPEN-SOURCE MULTI-PHYSICS SIMULATION ENGINE. A DETAILED USABILITY ASSESSMENT INVOLVING 41 SENIOR MECHANICAL ENGINEERING STUDENTS YIELDED PROMISING RESULTS, INDICATING THE VIRTUAL ROTOR KIT?S POTENTIAL TO ENHANCE COMPREHENSION OF VIBRATION PHENOMENA IN UNBALANCED ROTATING MACHINES. DESPITE REVEALING CERTAIN ISSUES RELATED TO THE GRAPHICAL USER INTERFACE AND THE APPLICATION'S EXECUTION TIME, THREE DEFINED ACHIEVEMENT INDICATORS DEMONSTRATED POSITIVE OUTCOMES FOR A VIRTUAL BALANCING LABORATORY EXPERIENCE USING THE VIRTUAL ROTOR KIT APPLICATION. BY FOCUSING ON THE DYNAMIC BEHAVIOR OF A ROTOR TEST RIG INSTEAD OF SIMULATING A SPECIFIC LABORATORY EXPERIENCE, THE APPLICATION OFFERS INSTRUCTORS GREATER FLEXIBILITY IN DEVELOPING LEARNING EXPERIENCES. UNLIKE OTHER VIRTUAL TESTBEDS, THE VIRTUAL ROTOR KIT ALLOWS STUDENTS TO CONDUCT BOTH STEADY-STATE AND TRANSIENT EXPERIMENTS, OFFERING A COMPREHENSIVE UNDERSTANDING OF ROTATING MACHINERY DYNAMICS. ADDITIONALLY, THE APPLICATION IS DISTRIBUTED UNDER THE BSD-3 LICENSE AND CAN SERVE AS A COMPLEMENT TO ON-SITE LABORATORY EXPERIENCES. THE RESULTS PRESENTED IN THIS STUDY INSPIRE FURTHER RESEARCH AND DEVELOPMENT TO ENHANCE ITS EFFICACY.

IN THE CURRENT EDITION OF THE EC3 PART 1?5, THE DESIGN PROVISIONS FOR LONGITUDINALLY STIFFENED PLATE GIRDERS SUBJECTED TO PATCH LOADING RESULT IN AN ENHANCED RESISTANCE FOR AN INCREASING DISTANCE OF THE STIFFENER, MEASURED FROM THE LOADED FLANGE. THIS IS IN CONTRAST TO THE ACTUAL BEHAVIOR OBSERVED EXPERIMENTALLY, WHICH SHOWS A DECREASING RESISTANCE FOR AN INCREASING DISTANCE OF THE STIFFENER. THE PROBLEM LIES IN THE DETERMINATION OF THE CRITICAL BUCKLING LOAD, WHICH INCREASES WITH THE STIFFENER LOCATION, ALSO AFFECTING THE CALCULATION OF THE SLENDERNESS OF THE PLATE GIRDER. AT ULTIMATE LOAD LEVEL, THE LONGITUDINAL STIFFENER RESTRICTS THE VERTICAL AND THE OUT-OF-PLANE DISPLACEMENTS OF THE WEB PANEL. THIS PAPER INVESTIGATES THE IMPACT OF VARIOUS HYPOTHESES REGARDING THESE DISPLACEMENTS ON THE DETERMINATION OF THE CRITICAL BUCKLING LOAD OF PLATE GIRDER WEBS WITH A SINGLE LONGITUDINAL STIFFENER. AT FIRST, THE STUDY IS PERFORMED THROUGH LINEAR BUCKLING ANALYSIS USING THE FINITE ELEMENT METHOD, IN WHICH VARIOUS DISPLACEMENTS RESTRICTIONS ARE APPLIED TO INVESTIGATE THEIR INFLUENCE ON THE BUCKLING RESPONSE OF THE STIFFENED GIRDERS. THE RESULTS SHOW THAT A FULL RESTRICTION OF THE DISPLACEMENTS OF THE STIFFENER IN THE VERTICAL, AS WELL AS IN THE OUT-OF-PLANE DIRECTION, LEAD TO AN IMPROVEMENT IN THE DETERMINATION OF THE SLENDERNESS OF THE WEB PANEL, AND HENCE THE RESISTANCE TO PATCH LOADING AT ULTIMATE LOAD LEVEL. FINALLY, EXPERIMENTAL RESULTS ARE COMPARED TO THOSE OBTAINED WITH A VALIDATED METHODOLOGY ATTAINING A GOOD AGREEMENT.