scholarly journals The Analysis of Beam-Column Joint Reinforced with Cross Bars according to SK SNI T-15-1991-03 on Cyclic Loads

2021 ◽  
pp. 1-10
Author(s):  
Zardan Araby ◽  
Samsul Rizal ◽  
Abdullah ◽  
Mochammad Afifuddin
Keyword(s):  
Test Specimen ◽  
Cyclic Load ◽  
Load Capacity ◽  
Maximum Load ◽  
Cyclic Loads ◽  
Concrete Compressive Strength ◽  
Dissipation Energy ◽  
Column Joint ◽  
The Moment ◽  
Inelastic Region

The primary structural component supporting the other structural loads in a building is the beam-column joint. It is considered a critical area of a building which needs to be accurately designed to ensure energy is dissipated properly during the occurrence of an earthquake. Beam-column joint has the ability to offer a proper structure required to transform cyclic loads in the inelastic region but also has a direct impact on the components connected to it during the occurrence of any failure. This is one of the reasons the beam-column connection needs to be designed carefully. Therefore, this study focused on designing a beam-column joint with reinforcement according to SK SNI T-15-1991 in order to withstand cyclic loads. The test specimen used was observed to have a concrete compressive strength of 19.17 MPa while the dimension of the beam was 120 x 30 x 40 cm and the column was 30 x 30 x 200 cm, having 8Ø13.4 mm bars with 310.03 MPa yield strength (fy) as well as Ø9.8-100 mm stirrup reinforcement with (fy) 374.59 MPa. The test was initiated through the provision of 0.75 mm, 1.5 mm, 3 mm, 6 mm, 12 mm, 24 mm monotonic cyclic loads at the end of the beam up to the moment the specimen cracked. A maximum load of 68.35 kN for the compression and 49.92 kN for the tension was required to attain the cyclic load capacity. The maximum load was attained at 50.98 mm displacement. Furthermore, beam-column with 23.93 mm displacement caused a reduction in capacity. Meanwhile, the load at 24 mm produced the cycle's highest dissipation energy of 13.25 but this can be increased through the addition of stirrups to provide stiffness in the joint. The stiffness value was also observed to have increased after the structural repairs.

Dynamic Behavior of Pure Squeeze Films in Narrow Porous Bearings

1974 ◽  
Vol 96 (3) ◽  
pp. 361-364 ◽  
Author(s):  
P. R. K. Murti
Keyword(s):  
Dynamic Behavior ◽  
Cyclic Load ◽  
Journal Bearing ◽  
Load Capacity ◽  
Squeeze Film ◽  
Closed Form Expression ◽  
Cyclic Loads ◽  
Eccentricity Ratio ◽  
Form Expression ◽  
Bearing Material

The dynamic behavior of squeeze film in a narrow porous journal bearing under a cyclic load is analyzed. A thin-walled bearing with a nonrotating journal is considered and a closed form expression for the pressure distribution is derived. The locus of the journal center is found by numerical methods and it is established with an example that actual contact between the journal and bearing can be avoided by appropriate design of the bearing. Consequently, it is proved that pure squeeze films have a load capacity only under cyclic loads. The analysis also reveals that the permeability of the bearing material and the wall thickness of the bearing influence significantly the operating eccentricity ratio.

Behavior of slab–column connections with partially debonded reinforcement under lateral loading

2009 ◽  
Vol 36 (3) ◽  
pp. 463-472 ◽  
Author(s):  
Jung-Wook Choi ◽  
Malika Ali ◽  
Scott D.B. Alexander
Keyword(s):  
Cyclic Load ◽  
Load Capacity ◽  
Slab Thickness ◽  
Drift Capacity ◽  
Lateral Drift ◽  
Column Structure ◽  
Column Joint ◽  
Loading Tests ◽  
Flexural Reinforcement ◽  
Cyclic Loading Tests

In a flat plate structure, slab–column connections must possess sufficient drift capacity to survive the lateral deformation resulting from wind or earthquake. Partial debonding of the flexural reinforcement may be a means of increasing drift capacity of a slab–column structure. This article summarizes cyclic loading tests conducted on two full-scale interior slab–column connections, one with and one without partially debonded reinforcement. Each test specimen consisted of a 4.2 m square slab with a 355 mm square column protruding 1.5 m above and below the slab. The slab thickness was 152 mm. The specimen with partially debonded reinforcement exhibited more lateral drift capacity (4.5%) than did the specimen with fully bonded reinforcement (3.5%). The lateral load capacity of the debonded specimen was approximately 20% greater than that of the bonded control specimen. With partial debonding of the flexural reinforcement, cyclic load appeared to produce less damage to the connection in the vicinity of the slab–column joint.

scholarly journals Comparison of Safety Factor Values for Soderberg and DIN 743 Fatigue Analyses

2021 ◽  
Vol 7 (2) ◽  
pp. 11-21
Author(s):  
Beatriz Henriques ◽  
Mariana Carvalho ◽  
Sérgio Tavares ◽  
Paulo De Castro
Keyword(s):  
Safety Factor ◽  
Cyclic Load ◽  
High Cycle Fatigue ◽  
Load Capacity ◽  
Cyclic Loads ◽  
Correction Factors ◽  
Fatigue Design ◽  
Different Types ◽  
Machine Elements ◽  
Critical Aspects

Fatigue phenomena are critical aspects of the life cycle of many components or structures. The variety of cyclic load situations led to the emergence, throughout the years, of different types of studies as high-cycle, low-cycle, and fatigue crack growth, among others. Particularly for machine elements, high-cycle fatigue situations are the more frequent, and simplified approaches taking into account the Soderberg criterion have been commonly used. Meanwhile, the German Institute for Standardization put forward a procedure for fatigue design of shafts, DIN 743, based on the use of Smith diagrams and considering separately the safety factor (SF) for static and for cyclic loads. The present paper compares Soderberg and DIN 743 approaches, focusing on SF obtained when load capacity is calculated considering equal correction factors in both methods. A set of representative situations was defined, and the comparison was carried out parametrically using Matlab software. The SF values of the Soderberg method were always found to be lower than those of DIN 743, indicating that the Soderberg method is more conservative than DIN 743.

The possibility of using myotonometry to assess the muscle fatigue of physical labor workers

2020 ◽  
Vol 60 (11) ◽  
pp. 892-894
Author(s):  
Evgeniya S. Shitova ◽  
Inga S. Malakhova ◽  
Vladislav I. Lemeshko
Keyword(s):  
Clinical Practice ◽  
Occupational Health ◽  
Muscle Fatigue ◽  
Soleus Muscle ◽  
Initial Level ◽  
Maximum Load ◽  
Main Area ◽  
Modern Methods ◽  
The Moment

Introduction. The use of classical methods for diagnosing muscle fatigue of physical workers, including dynamometry and electromyography, is often limited due to the complexity of the process, the inability to use them in production, and the subjectivity of the methodology. At the same time, such a method as myotonometry does not have these disadvantages, but the main area of its use at the moment is clinical practice. The aim of study was to determine the possibility of using myotonometry to assess muscle fatigue. Materials and methods. In the course of the study, the biomechanical characteristics of muscles that differ in their depth were evaluated using the "MyotonPro" device (Myoton AS, Estonia). We determined the tone and stiffness of the biceps of the shoulder, the soleus muscle, and the muscle that straightens the back at different periods of time under the influence of maximum load on them. Results. It was found that the studied parameters of these muscles immediately after performing a series of exercises "to failure" statistically significantly increased, and after 30 minutes - again decreased, but did not reach the initial level. Conclusions. The myotonometric study showed objectivity, reliability, repeatability and proved to be one of the most promising modern methods for assessing muscle fatigue, including for solving problems in the field of occupational health.

Experimental study of moment carrying behavior of typical Tibetan timber beam-column joints

2021 ◽  
pp. 136943322110015
Author(s):  
Ting Guo ◽  
Na Yang ◽  
Huichun Yan ◽  
Fan Bai
Keyword(s):  
Bending Moment ◽  
Structural Performance ◽  
Test Results ◽  
Timber Beam ◽  
Rotational Stiffness ◽  
Trilinear Model ◽  
Column Joint ◽  
Loading Tests ◽  
The Moment ◽  
Relationship Of

This study aimed to investigate the moment carrying behavior of typical Tibetan timber beam-column joints under monotonic vertical static load and also evaluate the influence of length ratio of Gongmu to beam (LRGB) and dowels layout on the structural performance of the joint. Six full-scale specimens were fabricated with same construction but different Gongmu length and dowels position. The moment carrying performance of beam-column joints in terms of failure mode, moment resistance, and rotational stiffness of joints were obtained via monotonic loading tests. Test results indicated that all joints are characterized by compressive failure perpendicular to grain of Ludou. Additionally, it was found that greater LRGB leads to greater initial rotational stiffness and maximum moment of the joint by an increase of restraint length for beam end; however, offsetting dowels toward column resulted smaller stiffness and ultimate bending moment of joints, particularly, offsetting Beam-Gongmu dowels toward column changed the moment-rotation curve pattern of the beam-column joint, accompanied by a hardening stiffness at last phase. Furthermore, a simplified trilinear model was proposed to represent the moment-rotation relationship of the typical Tibetan timber beam-column joint.

scholarly journals Design and Analysis of an Aerostatic Pad Controlled by a Diaphragm Valve

Lubricants ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 47
Author(s):  
Federico Colombo ◽  
Luigi Lentini ◽  
Terenziano Raparelli ◽  
Andrea Trivella ◽  
Vladimir Viktorov
Keyword(s):  
Sensitivity Analysis ◽  
High Precision ◽  
Load Capacity ◽  
Design Procedure ◽  
Maximum Load ◽  
Air Gap ◽  
Diaphragm Valve ◽  
Compensation Methods ◽  
Aerostatic Bearings ◽  
Gap Height

Because of their distinctive characteristics, aerostatic bearings are particularly suitable for high-precision applications. However, because of the compressibility of the lubricant, this kind of bearing is characterized by low relative stiffness and poor damping. Compensation methods represent a valuable solution to these limitations. This paper presents a design procedure for passively compensated bearings controlled by diaphragm valves. Given a desired air gap height at which the system should work, the procedure makes it possible to maximize the stiffness of the bearing around this value. The designed bearings exhibit a quasi-static infinite stiffness for load variation ranging from 20% to almost 50% of the maximum load capacity of the bearing. Moreover, the influence of different parameters on the performance of the compensated pad is evaluated through a sensitivity analysis.

Dependency of Machine Efficiency on the Thermal Behavior of Induction Machines

Machines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 9
Author(s):  
Svenja Kalt ◽  
Karl Ludwig Stolle ◽  
Philipp Neuhaus ◽  
Thomas Herrmann ◽  
Alexander Koch ◽  
...  
Keyword(s):  
Thermal Behavior ◽  
Electric Vehicles ◽  
Thermal Load ◽  
Load Capacity ◽  
Maximum Load ◽  
Induction Machines ◽  
Electric Machines ◽  
Model Parameters ◽  
Dynamic Operating ◽  
The Impact

The consideration of the thermal behavior of electric machines is becoming increasingly important in the machine design for electric vehicles due to the adaptation to more dynamic operating points compared to stationary applications. Whereas, the dependency of machine efficiency on thermal behavior is caused due to the impact of temperature on the resulting loss types. This leads to a shift of efficiency areas in the efficiency diagram of electric machines and has a significant impact on the maximum load capability and an impact on the cycle efficiency during operation, resulting in a reduction in the overall range of the electric vehicle. Therefore, this article aims at analyzing the thermal load limits of induction machines in regard to actual operation using measured driving data of battery electric vehicles. For this, a thermal model is implemented using MATLAB® and investigations to the sensitivity of model parameters as well as analysis of the continuous load capacity, thermal load and efficiency in driving cycles under changing boundary conditions are conducted.

An Accurate Solution of the Gas Lubricated, Flat Sector Thrust Bearing

1977 ◽  
Vol 99 (1) ◽  
pp. 82-88 ◽  
Author(s):  
I. Etsion ◽  
D. P. Fleming
Keyword(s):  
Film Thickness ◽  
Thrust Bearing ◽  
Load Capacity ◽  
Thickness Distribution ◽  
Maximum Load ◽  
Accurate Solution ◽  
Operating Conditions ◽  
Thrust Bearings ◽  
Practical Design ◽  
Minimum Film Thickness

A flat sector shaped pad geometry for gas lubricated thrust bearings is analyzed considering both pitch and roll angles of the pad and the true film thickness distribution. Maximum load capacity is achieved when the pad is tilted so as to create a uniform minimum film thickness along the pad trailing edge. Performance characteristics for various geometries and operating conditions of gas thrust bearings are presented in the form of design curves. A comparison is made with the rectangular slider approximation. It is found that this approximation is unsafe for practical design, since it always overestimates load capacity.

Design of Multi-Recess Hydrostatic Journal Bearings for Minimum Total Power Loss

1974 ◽  
Vol 96 (1) ◽  
pp. 226-232 ◽  
Author(s):  
C. Cusano ◽  
T. F. Conry
Keyword(s):  
Rotational Speed ◽  
Power Loss ◽  
Load Capacity ◽  
Maximum Load ◽  
Journal Bearings ◽  
Design Criterion ◽  
Total Power ◽  
Eccentricity Ratio ◽  
Constant Ratio ◽  
Design Charts

The design problem is formulated for multi-recess hydrostatic journal bearings with a design criterion of minimum total power loss. The design is subject to the constraints of constant ratio of the recess area to the total bearing area and maximum load capacity for a given recess geometry. The L/D ratio, eccentricity ratio, ratio of recess area to total bearing area, and shaft rotational speed are considered as parameters. The analysis is based on the bearing model of Raimondi and Boyd [1]. This model is generally valid for low-to-moderate speeds and a ratio of recess area-to-total bearing area of approximately 0.5 or greater. Design charts are presented for bearings having a ratio of recess area-to-total bearing area of 0.6 and employing capillary and orifice restrictors, these being the most common types of compensating elements. A design example is given to illustrate the use of the design charts.

Sign in / Sign up

Export Citation Format

Share Document