The Effect of Element Types on Force Analogy Method Analysis

In this study, the seismic performance of a 2D portal frame subjected to the recorded seismic ground motions of the Northridge 1994 earthquake was evaluated by the force analogy method (FAM) with different element types. To increase the accuracy of FAM, Timoshenko (TS) elements were employed instead of the classical Euler Bernoulli (EB) elements, to revert the shear deformations that are neglected in EB elements. To perform evaluation, the same material and section properties were considered and the same portal frame was analyzed with different element lengths, from 0.5 to 7.0 m in 0.5 m steps

A Novel Algorithm for Effective Vibration Control of Portal Frames

Severe vibrations such as earthquakes threaten to demolish or cause damage to built structures during their lifetime. Mitigation of such damage can be done by using control devices such as actuators. In this paper, an algorithm is proposed to analyze the nonlinear behavior of a portal frame supported by an actuator. The results were compared with those for a frame without actuator. The algorithm was developed in accordance with the Timoshenko beam element theory. ANSYS verified the results for the cases of a frame supported by a damper element and a frame without actuator. The results support the efficiency of the algorithm in reducing frame vibration and top-node displacement

METAPHOR OF MODALITY IN CLASSROOM INTERACTION

METAPHOR OF MODALITY IN CLASSROOM INTERACTION *Raissa Sati ** Dr. Siti Aisah Ginting, M.Pd **Indra Hartoyo, S.Pd, M. Hum ABSTRACT This study aims at analyzing the types and realization of metaphor of modality in classroom interaction of grade eleven Global Prima National Plus Medan. Qualitative research design was used by the researcher to conduct this study. The subjects of this study were the teacher and the students in grade eleven Global Prima National Plus Medan in academic 2018/2019. The data were collected by observed and recorded to find the types of metaphor of modality being used and also to find out how the metaphor of modality is realized in classroom interaction. The data were analyzed by using Miles and Huberman data analysis technique. The findings of the study show that teacher and students used all the types of metaphor of modality in classroom interaction, such as modalization (probability 86,79% with 46 occurances, usuality 1,88% with 1 occurance) and modulation (obligation 3,77% with 2 occurances, inclination 7,54% with 4 occurances) . Metaphor of modality in classroom interaction was realized by the category probability (think, believe, possible), usuality (ussually), obligation (be obligied to) dan inclination (be allowed, recommend, permission). Key words: Teaching, English, Culinary

Simulation Model of The Collision Event of Submarine Mudflows Exerting A Horizontal Pipeline

The collision between submarine slide and sub-sea pipelines was simulated through laboratory experiment in order to investigate drag force exerted by mudflow on pipe surface. Mud model used was slurry of kaolin clay-water mixtures. Gravity flow concepts of fluid mechanics principles were implemented by lock-exchange system. It was developed through the laboratory equipment of rectangular channel to generate the mudflow in water ambient. A crosswise pipe stem positioned at certain run-out distance. It was collided by mudflow. The collision attributes of velocity (u), Reynolds number (Re), maximum drag force exerted by mudflow (Fdmax) and drag force coefficient (Cd) were observed based on ratio between water depth (at pipe position) and pipe diameter, abbreviated as H/d. Overall, higher H/d ratio generated higher values of collision attributes. H/d ratio variations had similar constant of Power-law model expression in Re-Cd relationship. It proved that H/d ratio had not effect to Cd very much. The current experiment also generated a high similarity trend line of Re-Cd relationship graph with the previous study. It indicated that the content of clay material (i.e. kaolin) play a major role in mudflow movement and collision, whereas granular materials (used in previous study) provide an extra density

Study of regional monsoonal effects on landslide hazard zonation in Cameron Highlands, Malaysia

In general, landslides in Malaysia mostly occurred during northeast and southwest periods, two monsoonal systems that bring heavy rain. As the consequence, most landslide occurrences were induced by rainfall. This paper reports the effect of monsoonal-related geospatial data in landslide hazard modeling in Cameron Highlands, Malaysia, using Geographic Information System (GIS). Land surface temperature (LST) data was selected as the monsoonal rainfall footprints on the land surface. Four LST maps were derived from Landsat 7 thermal band acquired at peaks of dry and rainy seasons in 2001. The landslide factors chosen from topography map were slope, slope aspect, curvature, elevation, land use, proximity to road, and river/lake; while from geology map were lithology and proximity to lineament. Landslide characteristics were extracted by crossing between the landslide sites of Cameron Highlands and landslide factors. Using which, the weighting system was derived. Each landslide factors were divided into five subcategories. The highest weight values were assigned to those having the highest number of landslide occurrences. Weighted overlay was used as GIS operator to generate landslide hazard maps. GIS analysis was performed in two modes: (1) static mode, using all factors except LST data; (2) dynamic mode, using all factors including multi-temporal LST data. The effect of addition of LST maps was evaluated. The final landslide hazard maps were divided into five categories: very high risk, high risk, moderate, low risk, and very low risk. From verification process using landslide map, the landslide model can predict back about 13–16% very high risk sites and 70–93% of very high risk and high risk combined together. It was observed however that inclusion of LST maps does not necessarily increase the accuracy of the landslide model to predict landslide sites

The Effect of Element Types on Force Analogy Method Analysis

In this study, the seismic performance of a 2D portal frame subjected to the recorded seismic ground motions of the Northridge 1994 earthquake was evaluated by the force analogy method (FAM) with different element types. To increase the accuracy of FAM, Timoshenko (TS) elements were employed instead of the classical Euler Bernoulli (EB) elements, to revert the shear deformations that are neglected in EB elements. To perform evaluation, the same material and section properties were considered and the same portal frame was analyzed with different element lengths, from 0.5 to 7.0 m in 0.5 m steps

An approach for time-dependent reliability analysis of Jackup structures

This paper proposes an approach for evaluation of time dependent reliability of Jackup structures. An approach for signal processing using prolate spheroidal wave functions is combined with stochastic field representation method to represent ocean waves with least number of independent sources of uncertainty. First passage probability for dynamical systems subject to stochastic loading was then used in the formulation of the reliability approach. A simplified Jackup was modelled and used to demonstrate the time dependent reliability approach by propagating the uncertain wave load on the unit. In-house computer codes were developed for the analysis of the stochastic response in time-domain to obtain time dependent failure probabilities. The results were compared with those of a similar model in which the statistical method is used

Modelling of Tsunami Due to Submarine Landslide by Smoothed Particle Hydrodynamics Method

Submarine landslide is the most serious threat on both local and regional scales. By way of addition to destroying directly offshore structures, slope failures may also generate destructive tsunami waves. This study has developed a numerical model based on the Smoothed Particle Hydrodynamics (SPH) method to predict four stages of generation, propagation, run-up, and impact of tsunami phenomenon. The numerical predictions in the research were validated with results in the literature and experimental tests. The results of the physical and numerical results presented in this study effort to develop these rule of thumbs to clearly understand some of the mechanics that may play a role in the assessment of tsunami waves

Modelling of Tsunami Due to Submarine Landslide by Smoothed Particle Hydrodynamics Method

Submarine landslide is the most serious threat on both local and regional scales. By way of addition to destroying directly offshore structures, slope failures may also generate destructive tsunami waves. This study has developed a numerical model based on the Smoothed Particle Hydrodynamics (SPH) method to predict four stages of generation, propagation, run-up, and impact of tsunami phenomenon. The numerical predictions in the research were validated with results in the literature and experimental tests. The results of the physical and numerical results presented in this study effort to develop these rule of thumbs to clearly understand some of the mechanics that may play a role in the assessment of tsunami waves

A Novel Algorithm for Effective Vibration Control of Portal Frames

Severe vibrations such as earthquakes threaten to demolish or cause damage to built structures during their lifetime. Mitigation of such damage can be done by using control devices such as actuators. In this paper, an algorithm is proposed to analyze the nonlinear behavior of a portal frame supported by an actuator. The results were compared with those for a frame without actuator. The algorithm was developed in accordance with the Timoshenko beam element theory. ANSYS verified the results for the cases of a frame supported by a damper element and a frame without actuator. The results support the efficiency of the algorithm in reducing frame vibration and top-node displacement