Jun Iyama
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Estimation method of roof snow load using acceleration measurements: a case study on actual wooden building Open
In Japan's snowy regions, the significant accumulation of snow makes it impractical to design structures that can withstand the maximum snow load. To address this, many buildings are designed under the assumption that snow will be removed …
Investigation on Fracture Behavior of Electroslag Welding Joint with High-Performance Steel Open
This study aimed to investigate fracture behavior of electroslag welding (ESW) joint with 590-N/mm 2 class steel using numerical analysis, covering a range of material scales in the structural level. The extended Mohr–Coulomb (EMC) fractur…
ESTIMATING THE NUMBER AND DIRECTION OF PEDESTRIANS ON THE STAIRCASE USING ACCELERATION SENSORS AND INFRARED HUMAN DETECTION SENSORS Open
Installing sensor units consisting of an acceleration sensor, two motion sensors, and a Raspberry Pi on staircases, a system was developed to estimate the number and direction of pedestrians from sensor responses. Specifically, we construc…
Stress Resultant-Based Approach to Mass Assumption-Free Bayesian Model Updating of Frame Structures Open
Bayesian model updating facilitates the calibration of analytical models based on observations and the quantification of uncertainties in model parameters such as stiffness and mass. This process significantly enhances damage assessment an…
Probabilistic seismic performance estimation through surrogate model and unbiased multi‐fidelity Monte Carlo predictor Open
This study introduces an approach for probabilistic seismic performance estimation, which focuses on the probability of intensity measures exceeding a specified value based on engineering demand parameters. Conventional methods face challe…
Electroslag Welding Applications for Steel Building Construction in Japan: A State-of-the-Art Review Open
Electroslag welding (ESW) is advantageous for the improvement of the efficiency of welding thick steel plates, and the application of ESW has been gradually spreading to civil structures such as steel bridges and steel building structures.…
ESTIMATE OF STORY SHEAR FORCE AND FRAME STIFFNESS BY STRAIN RESPONSE MEASUREMENT OF STEEL STRUCTURE UNDER EARTHQUAKES Open
The seismic response records of acceleration and strain of a three-story steel structure building were obtained and analyzed. From the strain measurement, the shear force actually applied to the column or the story could be obtained, and t…
Shaking table test of steel truss frame focusing on acceleration and strain response for post-earthquake buckling evaluation Open
Large-span steel structures have been widely adopted in stadiums, airports, factories, and train stations because they provide a large space for multi-functional use. To ensure business continuity, post-earthquake damage surveys and struct…
FEASIBILITY STUDY OF MICROTREMOR SIGNALS FOR STRUCTURAL HEALTH MONITORING ON REAL STEEL BUILDING STRUCTURES Open
Square hollow section (SHS) columns are widely used in many Asian countries such as Japan and China for the construction of low-and middle-rise steel buildings.Post-earthquake damage surveys and structural condition assessments of this com…
View article: ESTIMATION OF THE NUMBER OF WALKING PEOPLE IN STAIRCASES USING INFRARED HUMAN DETECTION SENSORS
ESTIMATION OF THE NUMBER OF WALKING PEOPLE IN STAIRCASES USING INFRARED HUMAN DETECTION SENSORS Open
The spatial distribution of people in a building could provide valuable information for an effective guidance in emergency. This paper aims to develop a method to estimate the number of walking people in staircases using infrared human det…
MEASUREMENT OF DEFORMATION OF FULL-SCALE RC FRAME BY MEMS ACCELEROMETER Open
MEMS acceleration sensors were attached to columns, beams, a wall of a full-scale RC frame specimen subjected to static cyclic lateral loads. Rotation angles of the sensors relative to the gravitational acceleration direction were measured…
ESTIMATION METHOD OF ROOF SNOW LOAD USING ACCELERATION MEASUREMENT VALIDATION FOR AN OBSERVATIONAL BUILDING MODEL Open
In this paper, a method to evaluate the roof snow load using acceleration measurement is proposed. Its applicability was confirmed by being applied to snow load on a semi-full-scale wooden structure building model. The natural frequency ch…
DAMAGE OBSERVATION AND DETECTION USING ACCELEROMETER OF DRY PARTITION WALL INSTALLED IN STEEL MOMENT FRAME UNDER LARGE STORY DRIFT Open
From a viewpoint of continuous use of buildings after an earthquake, it is important to understand the behavior and damage progress of non-structural elements such as dry partition wall under a large deformation owing to earthquake, and to…
Detection of beam-end fractures in steel members based on local stiffness calculated by strain response Open
Detecting structural damage from earthquakes is a vital aspect of disaster response for ensuring the continued safe use of affected building structures. In this paper, a method is proposed for detecting beam-end fractures after earthquake …
Bending moment distribution estimation of an actual steel building structure by microstrain measurement under small earthquakes Open
Most structural health monitoring systems estimate the overall behavior by measuring the acceleration response, which cannot directly measure the stress or damage state of individual structural members. An alternative approach is to use st…
Detection of Fracture in Steel Members of Building Structures by Microstrain Measurement Open
This paper discusses a possibility of detecting structural damage caused by an earthquake, by measuring the time history of the strain of beams and columns before and/or after the earthquake. An index called “local stiffness” is defined as…
Experimental Study of the Ductility of a Submerged Arc Welded Corner Joint in a High-Performance Steel Built-Up Box Column Open
Submerged arc welding, which is generally used for the corner joint of box-section columns, is a welding process with a high heat input. The influence on the strength and toughness of the heat-affected zone is an important concern, especia…
FIELD STUDY OF FABRICATION TIME FOR WEB-CLAMPED BEAM-TO-COLUMN CONNECTION Open
Jun IYAMAー ーーーーーーー ＊
Threshold value and applicable range of nonlinear behavior detection method using second derivative of acceleration Open
A previously proposed nonlinearity detection method using the second derivative “snap” of the recorded absolute acceleration requires the determination of a threshold value based on the yield strength of the target vibration system, which …
Fracture strength of electroslag welding joint with high-performance steel Open
Τo clarify the fracture behavior of electroslag welding (ESW) joints, we used the connection of box-column flange and interior diaphragm made of high-performance steel SA440C. Owing to the large heat input, the ductility and notch toughnes…
STRUCTURAL DAMAGE TO SCHOOL GYMNASIUMS DUE TO THE 2016 KUMAMOTO EARTHQUAKE Open
This paper reports a reconnaissance result of structural damage to school gymnasiums caused by the 2016 Kumamoto Earthquake. A total of 328 gymnasiums built in Kumamoto and Oita prefectures has been investigated. 55% of investigated gymnas…
ESTIMATE OF MAXIMUM BENDING STRENGTH OF H-SHAPED STEEL BEAM BASED ON EIGENVALUE ANALYSIS CONSIDERING GEOMETRIC NONLINEARITY OF OUT-OF-PLANE DEFORMATION CAUSED BY INITIAL DEFLECTION Open
The bending strength of H-shaped beam is governed by material and geometric nonlinearity. Many estimation equations of the bending strength have been proposed and are currently used for actual structural design. One problem is that they ha…
OUTLINE OF RECONNAISSANCE OF DAMAGED STEEL SCHOOL BUILDINGS DUE TO THE 2016 KUMAMOTO EARTHQUAKE Open
This paper reports an outline of a reconnaissance result of 185 steel school buildings including 102 gymnasiums damaged by the 2016 Kumamoto Earthquake. The reconnaissance has been performed by the Damage Evaluation Working Group of the Su…
Probabilistic distribution estimation of residual deformation by numerical simulation considering variation and directivity of plastic deformations: Study on distribution of residual deformation after earthquakes, part 3 Open
This paper discusses a method to estimate the probability density function of the residual deformation of a bilinear single‐degree‐of‐freedom system with isotropic hardening or kinematic hardening; this method is more detailed compared to …
JOINT YIELD MOMENT DEGRADATION CAUSED BY OUT-OF-PLANE DEFORMATION BETWEEN BASE PLATES OF ATTACHMENT AND BEAM FLANGE Open
In this paper, the effect of out-of-plane deformation between attachment and beam flange on Joint yield moment of Web-clamped type beam-to-column connection was investigated. In this study, simple mechanical model implied following joint b…
COLLAPSE BEHAVIOR OF 18-STORY STEEL MOMENT FRAME ON SHAKING TABLE TEST UNDER LONG PERIOD GROUND MOTION Open
The importance of precaution against unexpected earthquakes was highlighted after the 2011 Great East Japan Earthquake. While Nankai trough mega quake and a Tokyo inland earthquake are expected in the near future, it is important to prepar…