scholarly journals Calculation features of wall panels with monolithic cement bond of layers in the stages of installation, transportation and maintenance

Vestnik MGSU ◽  
2019 ◽  
pp. 367-375 ◽  
Author(s):  
Elena A. Korol’ ◽  
Marina N. Berlinova
Keyword(s):  
Middle Layer ◽  
Structural Features ◽  
Design Parameters ◽  
Competitive Advantages ◽  
Design Standards ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Current Design ◽  
Infinite Variety ◽  
Construction Practice

Introduction. When building residential, public and administrative buildings of various spatial structural designs (monolithic, precast-monolithic, precast, etc.), it is common practice to design self-sustaining (non-structural) outer walls within a storey. Developing and using new design and fabrication solutions of multilayer industrial-made wall panels in modern construction practice makes actual the issue of improving methods of their calculation in different stages of maintenance and under various sorts and combinations of loads and effects. However, there is an infinite variety of possible loading levels in practice and, therefore, the same variety of design approaches would be required. This is obviously unacceptable for engineering calculations, hence it is necessary to provide a monolithic matrix bond of layers, both technologically and structurally, which can provide a generalized approach to the calculation of multilayer enclosing structures in accordance with current design standards. Materials and methods. The article describes structural features of a multilayer wall panel made of structural concrete with the middle layer of concrete with low thermal conductivity and monolithic bond of layers. These features have an influence on creation of a design model and a calculation procedure in the stages of transportation, installation and maintenance. Results. The article has examined the structures described above in the sense of design parameters that provide their competitive advantages in strength and maintenance as compared with conventional mass-built enclosures. Conclusions. The studies demonstrate that when combining loads of force and non-force character, stresses in the considered structure do not exceed allowable values in all the stages what proves the prospects of using the multilayer panels with monolithic bond of layers for erection of various-purpose frame-panel buildings.

scholarly journals Review on Local Buckling of Hollow Box FRP Profiles in Civil Structural Applications

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4159
Author(s):  
Mohammad Alhawamdeh ◽  
Omar Alajarmeh ◽  
Thiru Aravinthan ◽  
Tristan Shelley ◽  
Peter Schubel ◽  
...  
Keyword(s):  
Local Buckling ◽  
Cost Effective ◽  
Design Parameters ◽  
Structural Level ◽  
Research Gaps ◽  
Design Standards ◽  
Outer Corner ◽  
Open Section ◽  
Structural Applications ◽  
Current Design

Hollow box pultruded fibre-reinforced polymers (PFRP) profiles are increasingly used as structural elements in many structural applications due to their cost-effective manufacturing process, excellent mechanical properties-to-weight ratios, and superior corrosion resistance. Despite the extensive usage of PFRP profiles, there is still a lack of knowledge in the design for manufacturing against local buckling on the structural level. In this review, the local buckling of open-section (I, C, Z, L, T shapes) and closed-section (box) FRP structural shapes was systematically compared. The local buckling is influenced by the unique stresses distribution of each section of the profile shapes. This article reviews the related design parameters to identify the research gaps in order to expand the current design standards and manuals of hollow box PFRP profiles and to broaden their applications in civil structures. Unlike open-section profiles, it was found that local buckling can be avoided for box profiles if the geometric parameters are optimised. The identified research gaps include the effect of the corner (flange-web junction) radius on the local buckling of hollow box PFRP profiles and the interactions between the layup properties, the flange-web slenderness, and the corner geometry (inner and outer corner radii). More research is still needed to address the critical design parameters of layup and geometry controlling the local buckling of pulwound box FRP profiles and quantify their relative contribution and interactions. Considering these interactions can facilitate economic structural designs and guidelines for these profiles, eliminate any conservative assumptions, and update the current design charts and standards.

Reasons For The Collapse Of Bearing Structures Of The Steel Silo: Design Errors

2019 ◽  
pp. 4-8
Keyword(s):  
Design Standards ◽  
Metal Structures ◽  
Software Complex ◽  
Emergency Situations ◽  
Overall Design ◽  
Finite Element Software ◽  
Flat Base ◽  
Wall Panels ◽  
Current Design ◽  
Calculation Results

The problems of choosing the optimal design of a steel silo according to economic and technical indicators are analyzed. The design features of the silos with a flat base are given and the schematic diagram of the metal elements operation of the silo of this type as part of the overall design is described. It is emphasized that when designing the silos it is necessary to have the skills and experience of calculating these structures due to the specifics of their design. The calculation of metal structures of the silo is considered. The method of determining the loads acting on these structures in accordance with the current design standards is shown. The results of determining the efforts in wall panels of the silo obtained manually and with the help of finite element software complex LIRA SOFT 10.8 are presented. The estimation of bearing capacity of elements of metal designs of the silo and their connections among themselves is made. On the basis of the calculation results and survey materials, the causes of the collapse of the silo metal structures are analyzed, photos of the consequences of the collapse are presented. Recommendations on prevention of emergency situations connected with mistakes of silos designing are made.

scholarly journals Calculation of multilayer enclosing structures with middle layer of polystyrene concrete

2018 ◽  
Vol 193 ◽  
pp. 03020 ◽  
Author(s):  
Elena Korol ◽  
Marina Berlinova
Keyword(s):  
Middle Layer ◽  
Operating Conditions ◽  
Bending Moments ◽  
Rectangular Section ◽  
Strain Compatibility ◽  
Wall Structures ◽  
Wall Panels ◽  
Multilayer Wall ◽  
Combined Action ◽  
Concrete Elements

The strength and strain relations of characteristics of the layers in multilayer wall structures made of concrete of different strength are presented, the dependence of the stress values in the layers on the operating conditions of the structure is revealed. On the basis of the principle of strain compatibility of concrete and reinforcement, the estimation of the stress-strain state of multilayer wall panels is done taking into account the conditional concentrated shears in the joint between concretes. A calculation method is proposed, which is based on strains during the combined action of torque and bending moments of three-layer reinforced concrete elements with rectangular section in the stage of working with cracks.

Front steering design guidelines formulation for e-scooters considering the influence of sitting and standing riders on self-stability and safety performance

2021 ◽  
pp. 095440702199217
Author(s):  
Milan Paudel ◽  
Fook Fah Yap
Keyword(s):  
Preventive Measures ◽  
Recent Trend ◽  
Dynamic Performance ◽  
Design Guidelines ◽  
Safety Performance ◽  
Design Parameters ◽  
Single Track ◽  
Standing Posture ◽  
Last Mile ◽  
Current Design

E-scooters are a recent trend and are viewed as a sustainable solution to ease the first and last mile problem in modern transportation. However, an alarming rate of accidents, injuries, and fatalities have caused a significant setback for e-scooters. Many preventive measures and legislation have been put on the e-scooters, but the number of accidents and injuries has not reduced considerably. In this paper, the current design approach of e-scooters has been analyzed, and the most common range of design parameters have been identified. Thereafter, validated mathematical models have been used to quantify the performance of e-scooters and relate them with the safety aspects. Both standing and seated riders on e-scooters have been considered, and their influence on the dynamic performance has been analyzed and compared with the standard 26-in wheel reference safety bicycle. With more than 80% of the accidents and injuries occurring from falling or colliding with obstacles, this paper tries to correlate the dynamics of uncontrolled single-track vehicles with the safety performance of e-scooters. The self-stability, handling, and braking effect have been considered as major performance matrices. The analysis has shown that the current e-scooter designs are not as stable as the reference safety bicycle. Moreover, these e-scooters have been found unstable within the most common range of legislated riding velocity. The results corroborate with the general perception that the current designs of e-scooters are less stable, easy to lose control, twitchy, or wobbly to ride. Furthermore, the standing posture of the rider on the e-scooter has been found dangerous while braking to avoid any disturbances such as potholes or obstacles. Finally, the front steering design guidelines have been proposed to help modify the current design of e-scooters to improve the dynamic performance, hence the safety of the e-scooter riders and the surroundings.

A Study of the Anchor Effect Based on Structural Parameters of Flexible Pressurized Anchor and Pressure from Surrounding Rock

2011 ◽  
Vol 71-78 ◽  
pp. 4634-4637
Author(s):  
Tian Lin Cui ◽  
Jing Kun Pi ◽  
Yong Hui Liu ◽  
Zhen Hua He
Keyword(s):  
Structural Parameters ◽  
Structural Features ◽  
Surrounding Rock ◽  
Design Parameters ◽  
Optimized Design ◽  
Anchor Effect ◽  
The Finite Element Method ◽  
Anchor System ◽  
New Type ◽  
Stress Relation

In order to optimize the design of flexible pressurized anchor, this paper gives a further analysis on structural features of the new type of flexible pressurized anchor and carries out a contact analysis on anchor system by using the finite element method. It calculates as well as researches the contact stress relation of interactional anchor rod and surrounding rock under the circumstance of anchoring, obtaining the law of all major design parameters of anchor rod structure and pressure from surrounding rock influencing the anchoring performance and arriving at the conclusion that the anchor rod is adapted to various conditions of surrounding rock. They not only serve as important references for optimized design and application of anchor rod, but also provide a basis for the experiment of new type of anchor rod.

scholarly journals Damage during the 6–24 February 2017 Ayvacık (Çanakkale) earthquake swarm

2018 ◽  
Vol 18 (3) ◽  
pp. 921-934 ◽  
Author(s):  
Ramazan Livaoğlu ◽  
Mehmet Ömer Timurağaoğlu ◽  
Cavit Serhatoğlu ◽  
Mahmud Sami Döven
Keyword(s):  
Earthquake Swarm ◽  
Structural Features ◽  
Load Bearing Capacity ◽  
Distribution Maps ◽  
Mortar Strength ◽  
Development Level ◽  
Out Of Plane ◽  
Connection Type ◽  
Past Experiences ◽  
Construction Practice

Abstract. On 6 February 2017 an earthquake swarm began at the western end of Turkey. This was the first recorded swarm in the Çanakkale region since continuous seismic monitoring began in 1970. The number of earthquakes located increased during the following 10 days. This paper describes the output of a survey carried out in the earthquake-prone towns in the area of Ayvacık, Çanakkale, Turkey, in February 2017 after the earthquakes. Observations of traditional buildings were made on site at the rural area of Ayvacık. A description of the main structural features and their effects on the most frequently viewed damage modes were made according to in-plane, out-of-plane behavior of the wall regarding construction practice, connection type, etc. It was found that there were no convenient connections like cavity ties or sufficient mortar strength resulting in decreased and/or lack of lateral load bearing capacity of the wall. Furthermore, distribution maps of damaged/undamaged buildings according to villages, damage ratios, structures and damage levels are generated. Distribution maps showed that damage ratio of structures is higher in villages close to epicenter and decrease away from epicenter except Gülpınar, where past experiences and development level affect the construction quality.

Tubular Permanent Magnet Linear Synchronous Motor Thrust Optimization

2011 ◽  
Vol 383-390 ◽  
pp. 5640-5647
Author(s):  
Jing Hong Zhao ◽  
Jun Hong Zhang
Keyword(s):  
Permanent Magnet ◽  
Selection Process ◽  
Structural Features ◽  
Synchronous Motor ◽  
Linear Motor ◽  
Design Parameters ◽  
Linear Synchronous Motor ◽  
Parameters Selection ◽  
Motor Design ◽  
Practical Engineering

Detailed discussion design parameters selection process of thrust density optimization about the tubular permanent magnet linear synchronous motor. Analysis of different parameters on the thrust density laws. Two different magnetization forms linear motor is optimized. The optimal design parameters value is obtained. Finally analysis and comparison of the two structural features of linear motor. The motor design guide has practical engineering value.

scholarly journals Coiled-Coils: The Molecular Zippers that Self-Assemble Protein Nanostructures

2020 ◽  
Vol 21 (10) ◽  
pp. 3584 ◽  
Author(s):  
Won Min Park
Keyword(s):  
Modular Design ◽  
Coiled Coil ◽  
Molecular Complexes ◽  
Building Blocks ◽  
Structural Features ◽  
Coiled Coils ◽  
Design Strategies ◽  
Protein Motifs ◽  
Self Assembling ◽  
Current Design

Coiled-coils, the bundles of intertwined helical protein motifs, have drawn much attention as versatile molecular toolkits. Because of programmable interaction specificity and affinity as well as well-established sequence-to-structure relationships, coiled-coils have been used as subunits that self-assemble various molecular complexes in a range of fields. In this review, I describe recent advances in the field of protein nanotechnology, with a focus on programming assembly of protein nanostructures using coiled-coil modules. Modular design approaches to converting the helical motifs into self-assembling building blocks are described, followed by a discussion on the molecular basis and principles underlying the modular designs. This review also provides a summary of recently developed nanostructures with a variety of structural features, which are in categories of unbounded nanostructures, discrete nanoparticles, and well-defined origami nanostructures. Challenges existing in current design strategies, as well as desired improvements for controls over material properties and functionalities for applications, are also provided.

Intersection Design and Decision–Reaction Time for Older Drivers

1997 ◽  
Vol 1573 (1) ◽  
pp. 68-71 ◽  
Author(s):  
David W. Naylor ◽  
Johnny R. Graham
Keyword(s):  
Reaction Time ◽  
Reaction Times ◽  
Older Drivers ◽  
Design Standards ◽  
Older Driver ◽  
The Past ◽  
Sight Distance ◽  
Stop Sign ◽  
Current Design ◽  
Design Value

Trends in automobile and roadway use have changed drastically over the past several years. Changes in the trends include an increase in the percentage of licensed drivers, annual miles driven, and an increase in the number of older drivers. Of particular concern is the increase in the number of older drivers and the question of whether the current design standards adequately meet the needs of the older driver. In this study, the perception-reaction time variable used in calculating intersection sight distance at stop sign-controlled intersections was evaluated. The current design value for the perception–reaction time is 2.0 sec, which has been used since the 1940s when the driving population was much younger. A field experiment was performed to determine an appropriate value for today’s driving population. Subjects were covertly videotaped as they entered two rural and two urban stop sign-controlled interactions. Mean decision–reaction times were determined for an older and a younger group of subjects. The older group, consisting of 104 subjects, averaged 69.3 years of age and had a mean decision–reaction time of 1.32 sec. A group of 104 younger subjects, less than 30 years of age, had a mean decision–reaction time of 1.24 sec. The 85th percentile decision–reaction time for the older group was 1.86 sec and for the younger group, 1.66 sec. Both times were less than the current AASHTO design value of 2.0 sec.

Innovative Six Sigma Design Using the Eigenvector Dimension-Reduction (EDR) Method

2007 ◽  
Author(s):  
Lee J. Wells ◽  
Byeng D. Youn ◽  
Zhimin Xi
Keyword(s):  
Taguchi Method ◽  
Dimension Reduction ◽  
Uncertainty Propagation ◽  
Robust Design Optimization ◽  
Design Parameters ◽  
Quality Engineering ◽  
Control Factors ◽  
Current Design ◽  
Eigenvector Dimension Reduction ◽  
Mean And Variance

This paper presents an innovative approach for quality engineering using the Eigenvector Dimension Reduction (EDR) Method. Currently industry relies heavily upon the use of the Taguchi method and Signal to Noise (S/N) ratios as quality indices. However, some disadvantages of the Taguchi method exist such as, its reliance upon samples occurring at specified levels, results to be valid at only the current design point, and its expensiveness to maintain a certain level of confidence. Recently, it has been shown that the EDR method can accurately provide an analysis of variance, similar to that of the Taguchi method, but is not hindered by the aforementioned drawbacks of the Taguchi method. This is evident because the EDR method is based upon fundamental statistics, where the statistical information for each design parameter is used to estimate the uncertainty propagation through engineering systems. Therefore, the EDR method provides much more extensive capabilities than the Taguchi method, such as the ability to estimate not only mean and standard deviation of the response, but also the skewness and kurtosis. The uniqueness of the EDR method is its ability to generate the probability density function (PDF) of system performances. This capability, known as the probabilistic “what-if” study, provides a visual representation of the effects of the design parameters (e.g., its mean and variance) upon the response. In addition, the probabilistic “what-if” study can be applied across multiple design parameters, allowing the analysis of interactions among control factors. Furthermore, the implementation of the probabilistic “what-if” study provides a basis for performing robust design optimization. Because of these advantages, it is apparent that the EDR method provides an alternative platform of quality engineering to the Taguchi method. For easy execution by field engineers, the proposed platform for quality engineering using the EDR method, known as Quick Quality Quantification (Q3), will be developed as a Microsoft EXCEL add-in.

Sign in / Sign up

Export Citation Format

Share Document