scholarly journals Analisis Kekuatan Struktur Bangunan Dermaga Kayu di Babo Teluk Bintuni, Papua Barat

2021 ◽  
Vol 6 (2) ◽  
pp. 81-96
Author(s):  
Adan Kamarudin ◽  
Erizal
Keyword(s):  
Wave Force ◽  
Shear Forces ◽  
Pile Capacity ◽  
Allowable Deviation ◽  
Earthquake Force ◽  
Live Loads ◽  
Papua Barat ◽  
The Stability ◽  
External Loads ◽  
Static Shear

Analysis of structural strength to the conditions of the jetty Port Babo of Teluk Bintuni, West Papua is important to ensure the stability of the against external loads and forces. The purpose of this research is to analyse and evaluate the strength of structures, as well as assess the durability of jetty structures. Modeling using the SAP2000 program corresponds to as built drawing. The results of the calculation of the working load include dead loads, live loads, ship berth, ship mooring force, current force, wave force, and earthquake force. Energy due to ship collision loads and vessel berthing force can be reduced using a fender designed using rubber fenders seibu V300H. The results of the structural analysis show that the number of combined variants is sufficient up to the shape mode 12. The dynamic earthquake shear forces in the x and y directions are still smaller than the static shear forces, so it needs to be multiplied by a scale factor of 2,9. The deviation that occurs in the structure is still smaller than the allowable deviation of 350 mm. Beams are designed using reinforcement with diameter 22 mm and 25 mm. The stress ratio value at the pile meets the pile capacity. It can be said that overall the Babo Teluk Bintuni wharf is safe from the working load.

Nonlinear Analysis of Cable Net Structures Suspended from Arches with Block and Tackle Suspension System, Taking into Account the Friction of the Pulleys

2009 ◽  
Vol 24 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Krisztián Hincz
Keyword(s):  
Structural Analysis ◽  
Static Analysis ◽  
Simple Structure ◽  
Complex Structure ◽  
Numerical Procedure ◽  
Suspension System ◽  
Dynamic Relaxation ◽  
Final State ◽  
The Stability ◽  
External Loads

A numerical procedure for the static analysis of arch-supported tensile structures with block and tackle suspension system is presented. The procedure, based on dynamic relaxation, is suitable for a structural analysis both in the prestressing process and in a final state under external loads. The friction between the pulley and its shaft is also taken into account in the analysis. After the introduction of the developed procedure, two structures are presented as examples. The analysis of a very simple structure validates the procedure, then the analysis of a more complex structure, an arch-supported cable net roof illustrates the stability and efficiency of the procedure.

scholarly journals Skyrmions in anisotropic magnetic fields: strain and defect driven dynamics

MRS Advances ◽  
2019 ◽  
Vol 4 (11-12) ◽  
pp. 643-650 ◽  
Author(s):  
Richard Brearton ◽  
Maciej W. Olszewski ◽  
Shilei Zhang ◽  
Morten R. Eskildsen ◽  
Charles Reichhardt ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Gradient ◽  
Magnetic Field Gradient ◽  
Particle Model ◽  
Shear Forces ◽  
Magnetic Field Profile ◽  
Peak Broadening ◽  
Diffraction Patterns ◽  
The Stability ◽  
Magnetic Skyrmions

ABSTRACTMagnetic skyrmions are particle-like, topologically protected magnetization entities that are promising candidates for information carriers in racetrack-memory schemes. The transport of skyrmions in a shift-register-like fashion is crucial for their embodiment in practical devices. Recently, we demonstrated experimentally that chiral skyrmions in Cu2OSeO3 can be effectively manipulated by a magnetic field gradient, leading to a collective rotation of the skyrmion lattice with well-defined dynamics in a radial field gradient. Here, we employ a skyrmion particle model to numerically study the effects of resultant shear forces on the structure of the skyrmion lattice. We demonstrate that anisotropic peak broadening in experimentally observed diffraction patterns can be attributed to extended linear regions in the magnetic field profile. We show that topological (5-7) defects emerge to protect the six-fold symmetry of the lattice under the application of local shear forces, further enhancing the stability of proposed magnetic field driven devices.

scholarly journals Evaluation of the Hydraulic Performance of a Rear-Parapet Vertical Breakwater under Regular Waves through Hydraulic Experiments

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2428 ◽  
Author(s):  
Byeong Wook Lee ◽  
Woo-Sun Park
Keyword(s):  
Climate Change ◽  
Performance Evaluation ◽  
Storm Surges ◽  
Wave Force ◽  
Hydraulic Performance ◽  
Regular Waves ◽  
Pressure Transducers ◽  
Vertical Breakwater ◽  
The Stability ◽  
Impulsive Pressure

Climate change has resulted in increased intensity and frequency of typhoons and storm surges. Accordingly, attention has been paid to securing the breakwater’s stability to protect the safety of the port. Herein, hydraulic model experiments were conducted to evaluate the hydraulic performance of a vertical breakwater having a rear parapet. For comparison, cases in which the parapet was placed on the seaside, the harborside, and at the center of the breakwater were considered. Regular waves were used for convenient performance analysis. Five wave gauges and nine pressure transducers were installed to secure physical data for hydraulic performance evaluation. Results showed that a rear parapet can reduce the maximum wave force acting on the breakwater. Even though impulsive pressure was generated, it did not affect the stability of the breakwater owing to the phase difference between the maximum wave pressures acting on the caisson and parapet. By decreasing the maximum wave force, the required self-weight that satisfies the safety factor of 1.2 was reduced by up to 82.7%; the maximum bearing pressure was reduced by up to 47.6% compared with that of the parapet located on the seaside. Thus, the rear parapet was found to be more suitable for actual applications.

Motion and stability of caisson breakwaters under breaking wave impact

2001 ◽  
Vol 28 (6) ◽  
pp. 960-968 ◽  
Author(s):  
Y -Z Wang
Keyword(s):  
Dynamic Characteristics ◽  
Wave Force ◽  
Breaking Wave ◽  
Wave Impact ◽  
Sliding Motion ◽  
Rocking Motion ◽  
Overturning Moment ◽  
The Stability ◽  
Caisson Breakwater ◽  
Sliding Force

The possible motions of caisson breakwaters under dynamic load excitation include vibrating motion, vibrating–sliding motion, and vibrating–rocking motion. Three models are presented in this paper and are used to simulate the histories of vibrating–sliding–rocking motions of caissons under breaking wave impact. The effect of the dynamic characteristics of the caisson–foundation system and the motions on the displacement, rotation, sliding force, and overturning moment of caissons are investigated. It is shown that the sliding force of the caisson is different from the breaking wave force directly acting on the caisson due to the motion of the caisson and the sliding motion or rocking motion of the caisson can limit the sliding force or overturning moment of the caisson to a certain value. The sliding force never exceeds the friction force between the caisson and the foundation, and the overturning moment never exceeds the stability moment of the caisson. It is concluded that the wave conditions, the dynamic characteristics, and the motions of the caisson–foundation system should be considered in design.Key words: caisson breakwater, breaking wave, vibrating, sliding, rocking.

DISPERSION OF WAVE FORCES ON CAISSON BREAKWATERS USING INTERLOCKING SYSTEMS

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Jihye Seo ◽  
Jin-Hak Yi ◽  
Deock-Hee Won ◽  
Woo-Sun Park
Keyword(s):  
Incident Wave ◽  
Numerical Experiments ◽  
Wave Dispersion ◽  
Wave Force ◽  
Normal Direction ◽  
Wave Forces ◽  
Dispersion Characteristics ◽  
Dispersion Effect ◽  
The Stability

Interlocking caisson-type breakwaters have recently gained attention for enhancing the stability of the conventional breakwaters. In this study, the dispersion characteristics of wave forces using interlocking systems connecting the upper part of caissons with cables in the normal direction of breakwaters were investigated. Based upon numerical experiments, the higher wave forces are transmitted through the cable as the angle of incident wave increases, while the maximum allowable wave force was capable of being increased by sharing the wave forces with the adjacent caissons. It was also found that the larger the stiffness of the interlocking cable, the larger the wave-dispersion effect.

Stability of the High-Speed Journal Bearing Under Steady Load: 1—The Incompressible Film

1962 ◽  
Vol 84 (3) ◽  
pp. 351-357 ◽  
Author(s):  
M. M. Reddi ◽  
P. R. Trumpler
Keyword(s):  
High Speed ◽  
Journal Bearing ◽  
Orbital Motion ◽  
Hydrodynamic Force ◽  
Nonlinear Differential Equations ◽  
Equations Of Motion ◽  
Static Equilibrium ◽  
The Stability ◽  
External Loads ◽  
Steady Load

The phenomenon of oil-film whirl in bearings subjected to steady external loads is analyzed. The journal, assumed to be a particle mass, is subjected to the action of two forces; namely, the external load acting on the bearing and the hydrodynamic force developed in the fluid film. The resulting equations of motion for a full-film bearing and a 180-deg partial-film bearing are developed as pairs of second-order nonlinear differential equations. In evaluating the hydrodynamic force, the contribution of the shear stress on the journal surface is found to be negligible for the full-film bearing, whereas for the partial-film bearing it is found to be significant at small attitude values. The equations of motion are linearized and the coefficients of the resulting characteristic equations are studied for the stability of the static-equilibrium positions. The full-film bearing is found to have no stable static-equilibrium position, whereas the 180-deg partial-film bearing is found to have stable static-equilibrium positions under certain parametric conditions. The equations of motion for the full-film bearing are integrated numerically on a digital computer. The results show that the journal center, depending on the parametric conditions, acquired either an orbital motion or a dynamical path of increasing attitude terminating in bearing failure.

Behavior and Mechanisms of Bolt Self-Loosening Under Transverse Load Due to Vibrations of a Washer Along an Arc

2008 ◽  
Author(s):  
Yasuo Fujioka
Keyword(s):  
Fe Analysis ◽  
The Other ◽  
Transverse Load ◽  
Shear Forces ◽  
Center Of Rotation ◽  
Concentric Circles ◽  
Instantaneous Center ◽  
Screw Threads ◽  
External Loads ◽  
Good Agreement

Self-loosening mechanisms of a bolt were investigated by Finite Element Method, under the assumption of a twist at the center of a circular joined structure in which the bolt was set along a certain pitch circle. In this structure, the bolt is loosened by combining the translational and rotational external loads. In the case of a large pitch circle structures in which self-loosening occurs, the directions of friction shear forces on the threads were along concentric circles; however, the instantaneous center of rotation was located one-side near the thread surface, and the center was eccentric with the axis of the bolt. If the radius of the pitch circle is set smaller, the instantaneous center of rotation moves closer to the center of the bolt, and finally reaches to the same position at the center of the bolt. On the other hand, the directions of friction shear forces on pitch diameter of one thread were calculated theoretically using the inclination and friction on a pressure flank. The results were in good agreement with FE analysis. By considering these mechanisms, it was estimated that the number of occurrence of self-loosening in one vibration cycle changes at the border when the diameter value of the pitch circle equals that of the screw threads. If the diameter of the pitch circle becomes smaller than that of the screw threads, the number changes from two to one. With the exception of torsional center-fastened structures, since the pitch circle is very small, self-loosening of general joined structures will occur twice in one vibration cycle.

Modeling Analysis of Crack Repairing Structures for Asphalt Concrete Pavement

2013 ◽  
Vol 639-640 ◽  
pp. 377-381 ◽  
Author(s):  
Yi Chi ◽  
Jian Yin
Keyword(s):  
Asphalt Concrete ◽  
Composite Structure ◽  
Concrete Pavement ◽  
Concrete Pavements ◽  
Filling Materials ◽  
Modeling Analysis ◽  
Strain Stress ◽  
The Stability ◽  
Asphalt Concrete Pavement ◽  
External Loads

Crack is one of the major distresses in asphalt concrete pavements, which could significantly reduce the safety and amenity of driving, even the performance of the whole pavement structure. By means of diverse crack repairing manners, the durability and whole service life of the pavement can be improved and extended. After repairing, a composite structure of the repairing system is formed which consists of new crack filling materials and original asphalt concrete matrixes. In order to resist the external loads on the pavement, the composite structure mush work as an integrated structure and maintain sufficient adhesive strength. Therefore, the deformation compatibility of the composite structure is the vital performance for the stability and durability of the entire repairing system. In this study, a modeling analysis for the composite structure under various service conditions was carried out utilizing MIDAS software. The vertical and transverse deformation, transverse and longitudinal normal stress were analyzed by simulating the composite structure under several serving conditions. Based on the results，it was found that the strain, stress and related properties of the repair material and asphalt concrete matrixes could meet the requirements for an asphalt concrete pavement, and the compatibility of the composite structure was also satisfactory.

Soil failure in shallow covers above flexible conduits

1983 ◽  
Vol 10 (4) ◽  
pp. 654-661 ◽  
Author(s):  
Hisham Hafez ◽  
George Abdel-Sayed
Keyword(s):  
Soil Cover ◽  
Stress Transfer ◽  
Critical Limit ◽  
Element Analysis ◽  
Soil Failure ◽  
Failure Propagation ◽  
Live Loads ◽  
Minimum Depth ◽  
The Stability ◽  
Good Agreement

Field experience has shown that shallow soil covers above large flexible conduits may fail under concentrated live loads. To avoid such failure, an empirical minimum depth of cover of one-sixth of the span of the conduit is required by the design codes, irrespective of the shape of the conduit.The present paper examines the stability of the soil cover using a finite-element analysis in which the soil stresses are calculated in the upper zone of the mesh. Failure in a soil element is determined using Mohr–Coulomb criteria. A stress transfer technique is used to distribute the stresses exceeding the failure limit between neighbouring elements. Failure propagation is detected when the live load reaches a critical limit. Analytical results are in good agreement with laboratory test results.A parametric study shows that the stability of soil cover is governed by height of cover, conduit shape and size, and the eccentricity of the live axle loads. It also shows that the present code requirements are not adequate for horizontal ellipses, and are too conservative for vertical ellipses.

Stability of a Gyroelastic Plate

2000 ◽  
Author(s):  
K. Yamanaka ◽  
G. R. Heppler
Keyword(s):  
Aspect Ratio ◽  
Boundary Conditions ◽  
Thin Plate ◽  
Equations Of Motion ◽  
Stability Regions ◽  
Gyroscopic Stabilization ◽  
The Stability ◽  
External Loads

Abstract An model of a gyroelastic thin plate is presented. The equations of motion and boundary conditions are derived when the system is subject to in-plane external loads. It is shown that these systems can display both static instabilities (divergence) and dynamic instabilities (flutter), that the structure of the stability regions depends on the aspect ratio of the plate and that gyroscopic stabilization is sometimes possible.

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