New Methodology for Designing ATFP Using the Modified Alternate Load Path Method

2017 ◽  
Author(s):  
Ayman Elfouly ◽  
Ahmed Khalil ◽  
Nabil A. Rahman
Keyword(s):  
Load Path

scholarly journals IDENTIFICATION AND MODELLING PROCESS OF DEFINING TEMPERATURE GRADIENT IN AIRPORT PAVEMENT

Aviation ◽  
2014 ◽  
Vol 18 (2) ◽  
pp. 72-79
Author(s):  
Ervina Ahyudanari ◽  
Nasir Shafiq ◽  
Ibrahim Kamaruddin
Keyword(s):  
Temperature Gradient ◽  
Solar Radiation ◽  
Cyclic Load ◽  
Gap Analysis ◽  
Load Path ◽  
Construction Design ◽  
Airport Pavement ◽  
Pavement Temperature ◽  
Pavement Structures ◽  
Safety Operation

Preserving airport pavement means guarantying the safety operation of aircraft movements. There are four aspects that cause progressive pavement deterioration, i.e. the construction design and process, selected material, and maintenance management. One of the traffic aspects, jet engine exhaust, has not been discovered yet. The load pattern of the jet exhaust follows the schedule of aircraft traffic. The assumption held in this research is that the thermal load during aircraft movement may generate a high temperature, which is induced into pavement layers. The objective of this research is to determine the temperature gradient in the pavement, caused by the jet exhaust. This paper discusses the process of determining the temperature gradient in four stages, i.e. by carrying out the gap analysis, evaluation of pavement structures, determination of the load path and the magnitude, and defining the temperature gradient. The temperature gradient in the pavement layer is determined through the development of a model of cyclic loading. The thermal cyclic load follows the aircraft schedule pattern. The pavement temperature receives the thermal cyclic load of the sinusoid of solar radiation. The results indicate that the temperature of the pavement is increased and pavement temperature rises by 35 °C. However, after 60 seconds the remaining temperature of the pavement layer decreases to the initial temperature, which is caused by solar radiation.

Weak-Link Analysis of Motor-Operated Butterfly Valve

2002 ◽  
Author(s):  
Donghae Kim
Keyword(s):  
Structural Integrity ◽  
Weak Link ◽  
Link Analysis ◽  
Seismic Load ◽  
Seismic Loads ◽  
Static Force ◽  
Bending Stress ◽  
Butterfly Valve ◽  
Load Path ◽  
Valve Assembly

The purpose of this paper is to address the structural integrity of the motor operated butterfly valve assembly by providing the methodology and equations to quantitatively determine the permissible component load in the load path from the operator to the valve. The weak link analysis is to determine the maximum allowable torque on the butterfly valve by equating the stresses caused by the torque and seismic load with the appropriate allowable stress value, and then the unknown torque is solved. Analysis methods are based on classical static force balancing equations and on classical axial, shear, and bending stress equations using the worst possible load combinations including seismic loads resulting from design basis earthquake.

Reverse Engineering the Structure and Function of the Allegheny Mound Ant Neck (Insecta, Hymenoptera, Formica, Exsectoides)

2012 ◽  
Author(s):  
Vienny N. Nguyen ◽  
Blaine W. Lilly ◽  
Carlos E. Castro
Keyword(s):  
Mechanical Design ◽  
Structure And Function ◽  
Load Path ◽  
Supporting Surface ◽  
Form And Function ◽  
Formica Exsectoides ◽  
Sem Imaging ◽  
Heavy Loads ◽  
And Function ◽  
Mass Loads

Insects as mechanical systems have been optimized for form and function over millions of years. Ants, in particular, can lift and carry extremely heavy loads relative to their body mass. Loads are lifted with the mouthparts, transferred through the neck joint to the thorax, and distributed over six legs and feet that anchor to the supporting surface. While previous research efforts have explored attachment mechanisms of the feet, little is known about the mechanical design of the neck — the single joint that connects the load path from the thorax to the head. This work combines mechanical testing, computed tomography (CT) and scanning electron microscope (SEM) imaging, and computational modeling to better understand the mechanical structure-function relation of the ant neck joint.

Learnings from the Field Implementation of a Novel Ultra-High Performance Concrete Beam End Repair on a Corroded Steel Girder Bridge in Connecticut

2021 ◽  
pp. 036119812110041
Author(s):  
Alexandra Hain ◽  
Arash E. Zaghi
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Implementation Process ◽  
Lessons Learned ◽  
Load Path ◽  
Ultra High Performance Concrete ◽  
Steel Girder Bridge ◽  
Aging Steel ◽  
Girder Bridge ◽  
The University

Corrosion at steel beam ends is one of the most pressing challenges in the maintenance of aging bridges. To tackle this challenge, the Connecticut Department of Transportation (DOT) has partnered with the University of Connecticut to develop a repair method that benefits from the superior mechanical and durability characteristics of ultra-high performance concrete (UHPC) material. The repair involves welding shear studs to the intact portions of the web and encasing the beam end with UHPC. This provides an alternate load path for bearing forces that bypasses the corroded regions of the beam. The structural viability of the repair has been extensively proven through small- and full-scale experiments and comprehensive finite element simulations. Connecticut DOT implemented the repair for the first time in the field on a heavily trafficked four-span bridge in 2019. The UHPC beam end repair was chosen because of the access constraints and geometric complexities of the bridge that limited the viable repair options. Four of the repaired beam ends were fully instrumented to collect data on the performance of the repaired locations before casting, during curing, and for approximately 6 months following the application of the repair. This paper provides an overview of the successful repair implementation and presents the lessons learned during construction. Select data from the monitored beam ends are presented. It is expected that this information will provide engineers with a better understanding of the repair implementation process, and thus provide an additional repair option for states to enhance the safety of aging steel bridges.

Postbuckling mechanics in slender steel plates under pure shear: A focus on boundary conditions and load path

2021 ◽  
Vol 169 ◽  
pp. 108448
Author(s):  
Peter Y. Wang ◽  
Parfait M. Masungi ◽  
Maria E.M. Garlock ◽  
Spencer E. Quiel
Keyword(s):  
Boundary Conditions ◽  
Pure Shear ◽  
Steel Plates ◽  
Load Path

Failure behavior analysis of steel strip–reinforced flexible pipe under combined tension and internal pressure

2018 ◽  
Vol 33 (6) ◽  
pp. 727-753
Author(s):  
Wei Chen ◽  
Haichao Xiong ◽  
Yong Bai
Keyword(s):  
Internal Pressure ◽  
Numerical Study ◽  
Steel Strip ◽  
Sensitivity Study ◽  
Failure Behavior ◽  
Load Path ◽  
Flexible Pipe ◽  
Fe Method ◽  
Axial Extension ◽  
The Relationship

The mechanical behaviors of steel strip–reinforced flexible pipe (steel strip PSP) under combined axial extension → internal pressure ( T→ P) load path were investigated. Typical failure characteristics of pipe samples under pure internal pressure and T→ P load path were identified in the full-scale experiments. A theoretical model for pipe under tension load was proposed to capture the relationship between axial extension of the pipe body and stress state of the steel strip. Numerical study based on finite element (FE) method was conducted to simulate the experiment process, and good agreement between FE data and experiment results were observed. Sensitivity study was conducted to study the effect of some key parameters on the pipe antiburst capacities in T→P load path; the effect of preloaded internal pressure on the pipe tensile capacity in P→T load path was also studied. Useful conclusions were drawn for the design and application of the steel strip PSP.

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