Static Analysis of a Microscale Cricket Filiform Hair Socket

2014 ◽  
Author(s):  
A. Hossain ◽  
A. Mian
Keyword(s):  
Static Analysis ◽  
Sensory System ◽  
Mems Devices ◽  
Low Velocity ◽  
Element Analysis ◽  
Physical Conditions ◽  
Fea Model ◽  
Highly Sensitive ◽  
Filiform Hair ◽  
Spiking Activity

Filiform hairs of crickets are of great interest to engineers because of their highly sensitive response to low velocity air currents. In this study, the cercal sensory system of a common house cricket has been analyzed. The sensory system consists of two antennae like appendages called cerci that are situated at the rear of the cricket’s abdomen. Each cercus is covered with 500–750 flow sensitive hairs that are embedded in a complex viscoelastic socket that acts as a spring -dashpot system and guides the movement of the hair. When the hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron and the combined spiking activity of all hairs are extracted by the cercal sensory system. The hair has been experimentally studied by few researchers though its characteristics are not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint. Therefore, this study aims to understand the socket’s behavior and its interaction with the filiform hair by conducting static analysis. First, a 3D Finite Element Analysis (FEA) model, representing hair and hair-socket, has been developed. Then the static analysis is conducted utilizing the appropriate load and boundary conditions based on the physical conditions that an insect experiences. These numerical analyses aid to understand the deformation mechanism the hair and hair-socket system. The operating principles of the hair and hair-socket could be used for the design of highly responsive MEMS devices such as fluid flow sensors or micro-manipulators.

Dynamic Analysis of a Microscale Cricket Filiform Hair Socket

2015 ◽  
Author(s):  
A. Hossain ◽  
A. Mian
Keyword(s):  
Dynamic Response ◽  
Dynamic Analysis ◽  
Sensory System ◽  
Mems Devices ◽  
Low Velocity ◽  
Element Analysis ◽  
Physical Conditions ◽  
Fea Model ◽  
Filiform Hair ◽  
Spiking Activity

Filiform hairs of crickets are of great interest to engineers because of their highly sensitive response to low velocity air currents. In this study, the cercal sensory system of a common house cricket has been analyzed. The sensory system consists of two antennae like appendages called cerci that are situated at the rear of the cricket’s abdomen. Each cercus is covered with 500–750 flow sensitive hairs that are embedded in a complex viscoelastic socket that acts as a spring -dashpot system and guides the movement of the hair. When the hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron and the combined spiking activity of all hairs are extracted by the cercal sensory system. The hair has been experimentally studied by few researchers though its characteristics are not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint. Therefore, this study aims to understand the dynamic response of socket and its interaction with the filiform hair. First, a 3D Finite Element Analysis (FEA) model, representing hair and hair-socket, has been developed. Then the dynamic analysis is conducted utilizing the appropriate load and boundary conditions based on the physical conditions that an insect experiences. These numerical analyses aid to understand the dynamic response of the hair and hair-socket system. The operating principles of the hair and hair-socket could be used for the design of highly responsive MEMS devices such as fluid flow sensors or micro-manipulators.

Biomechanical Analysis of a Filiform Mechanosensory Hair Socket of Crickets

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Kanishka Joshi ◽  
Ahsan Mian ◽  
John Miller
Keyword(s):  
Computer Aided Design ◽  
Three Dimensional ◽  
Sensory System ◽  
Biomechanical Properties ◽  
Biomechanical Analysis ◽  
Low Velocity ◽  
Physical Conditions ◽  
Highly Sensitive ◽  
Aided Design ◽  
Spiking Activity

Filiform mechanosensory hairs of crickets are of great interest to engineers because of the hairs' highly sensitive response to low-velocity air-currents. In this study, we analyze the biomechanical properties of filiform hairs of the cercal sensory system of a common house cricket. The cercal sensory system consists of two antennalike appendages called cerci that are situated at the rear of the cricket's abdomen. Each cercus is covered with 500–750 flow sensitive filiform mechanosensory hairs. Each hair is embedded in a complex viscoelastic socket that acts as a spring and dashpot system and guides the movement of the hair. When a hair deflects due to the drag force induced on its length by a moving air-current, the spiking activity of the neuron that innervates the hair changes and the combined spiking activity of all hairs is extracted by the cercal sensory system. Filiform hairs have been experimentally studied by researchers, though the basis for the hairs' biomechanical characteristics is not fully understood. The socket structure has not been analyzed experimentally or theoretically from a mechanical standpoint, and the characterization that exists is mathematical in nature and only provides a very rudimentary approximation of the socket's spring nature. This study aims to understand and physically characterize the socket's behavior and interaction with the filiform hair by examining hypotheses about the hair and socket biomechanics. A three-dimensional computer-aided design (CAD) model was first created using confocal microscopy images of the hair and socket structure of the cricket, and then finite-element analyses (FEAs) based on the physical conditions that the insect experiences were simulated. The results show that the socket can act like a spring; however, it has two-tier rotational spring constants during pre- and postcontacts of iris and hair bulge due to its constitutive nonstandard geometric shapes.

Tire Bead Overheating in Urban Buses and Trucks Using Drum Brake Systems

1998 ◽  
Vol 26 (1) ◽  
pp. 51-62
Author(s):  
A. L. A. Costa ◽  
M. Natalini ◽  
M. F. Inglese ◽  
O. A. M. Xavier
Keyword(s):  
Heat Transfer ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Energy ◽  
Structural Integrity ◽  
Experimental Temperature ◽  
Temperature Profiles ◽  
Element Analysis ◽  
Drum Brake ◽  
Fea Model

Abstract Because the structural integrity of brake systems and tires can be related to the temperature, this work proposes a transient heat transfer finite element analysis (FEA) model to study the overheating in drum brake systems used in trucks and urban buses. To understand the mechanics of overheating, some constructive variants have been modeled regarding the assemblage: brake, rims, and tires. The model simultaneously studies the thermal energy generated by brakes and tires and how the heat is transferred and dissipated by conduction, convection, and radiation. The simulated FEA data and the experimental temperature profiles measured with thermocouples have been compared giving good correlation.

scholarly journals Design and Modeling of a Bio-Inspired Flexible Joint Actuator

Actuators ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 95
Author(s):  
Ming Xu ◽  
Cheng Rong ◽  
Long He
Keyword(s):  
Hydraulic System ◽  
Driving Forces ◽  
Theoretical Models ◽  
Element Analysis ◽  
Flexible Joint ◽  
Fea Model ◽  
The Finite Element Analysis ◽  
Series Of Experiments ◽  
The Mathematical Model ◽  
Moving Speed

Spiders rely on a hydraulic system to stretch their legs but use muscles to make their legs flex. The compound drive of hydraulics and muscle makes an integrate dexterous structure with powerful locomotion abilities, which perfectly meets the primary requirements of advanced robots. Inspired by this hydraulics-muscle co-drive joint, a novel flexible joint actuator was proposed and its driving characteristics were preliminarily explored. The bio-inspired flexible joint manifested as a double-constrained balloon actuator, which was fabricated by the composite process of 3D printing and casting. To evaluate its performance, the mathematical model was deduced, as well as the finite element analysis (FEA) model. A series of experiments on the rotation angles, driving forces, and efficiencies of the flexible joint were carried out and compared with the mathematical calculations and FEA simulations. The results show that the accuracy of the two theoretical models can be used to assess the joint actuator. The locomotion test of a soft arthropod robot with two flexible joints was also implemented, where the moving speed reached 22 mm/s and the feasibility of the proposed flexible joint applied to a soft robot was demonstrated.

Effect of Residual Stress or Plastic Deformation History on Fatigue Life Simulation of Pipeline Dents

2018 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Rick Wang
Keyword(s):  
Residual Stress ◽  
Plastic Deformation ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Three Dimensional ◽  
Strain History ◽  
Deformation History ◽  
Stress Strain ◽  
Element Analysis ◽  
Fea Model

Mechanical dents often occur in transmission pipelines, and are recognized as one of major threats to pipeline integrity because of the potential fatigue failure due to cyclic pressures. With matured in-line-inspection (ILI) technology, mechanical dents can be identified from the ILI runs. Based on ILI measured dent profiles, finite element analysis (FEA) is commonly used to simulate stresses and strains in a dent, and to predict fatigue life of the dented pipeline. However, the dent profile defined by ILI data is a purely geometric shape without residual stresses nor plastic deformation history, and is different from its actual dent that contains residual stresses/strains due to dent creation and re-rounding. As a result, the FEA results of an ILI dent may not represent those of the actual dent, and may lead to inaccurate or incorrect results. To investigate the effect of residual stress or plastic deformation history on mechanics responses and fatigue life of an actual dent, three dent models are considered in this paper: (a) a true dent with residual stresses and dent formation history, (b) a purely geometric dent having the true dent profile with all stress/strain history removed from it, and (c) a purely geometric dent having an ILI defined dent profile with all stress/strain history removed from it. Using a three-dimensional FEA model, those three dents are simulated in the elastic-plastic conditions. The FEA results showed that the two geometric dents determine significantly different stresses and strains in comparison to those in the true dent, and overpredict the fatigue life or burst pressure of the true dent. On this basis, suggestions are made on how to use the ILI data to predict the dent fatigue life.

Determination of Critical Crack Size Utilizing a Fracture Mechanics Test in Equipment Under Fatigue

2009 ◽  
Author(s):  
Irene Garcia Garcia ◽  
Radoslav Stefanovic
Keyword(s):  
Heat Treatment ◽  
Fracture Mechanics ◽  
Crack Size ◽  
Operational Experience ◽  
Element Analysis ◽  
Critical Crack ◽  
Circumferential Welds ◽  
Fea Model ◽  
Critical Crack Size

Equipment that is exposed to severe operational pressure and thermal cycling, like coke drums, usually suffer fatigue. As a result, equipment of this sort develop defects such as cracking in the circumferential welds. Operating companies are faced with the challenges of deciding what is the best way to prevent these defects, as well as determining how long they could operate if a defect is discovered. This paper discusses a methodology for fracture mechanics testing of coke drum welds, and calculations of the critical crack size. Representative samples are taken from production materials, and are welded employing production welding procedures. The material of construction is 1.25Cr-0.5Mo low alloy steel conforming to ASME SA-387 Gr 11 Class 2 in the normalized and tempered condition (N&T). Samples from three welding procedures (WPS) are tested: one for production, one for a repair with heat treatment, and one for repair without heat treatment. The position and orientation of test specimen are chosen based on previous surveys and operational experience on similar vessels that exhibited cracks during service. Fracture mechanics toughness testing is performed. Crack finite element analysis (FEA) model is used to determine the path-independed JI-integral driving force. Methodology for the determination of critical crack size is developed.

Response of Mild Steel Pipes Under High Mass Low Velocity Impacts

2014 ◽  
Author(s):  
Shamsoon Fareed ◽  
Ian May
Keyword(s):  
Finite Element ◽  
Mild Steel ◽  
Impact Energy ◽  
High Mass ◽  
Low Velocity ◽  
Element Analysis ◽  
Steel Pipes ◽  
Impact Tests ◽  
The Finite Element Analysis ◽  
The Impact

Accidental loads, for example, due to heavy dropped objects, impact from the trawl gear and anchors of fishing vessels can cause damage to pipelines on the sea bed. The amount of damage will depend on the impact energy. The indentation will be localized at the contact area of the pipe and the impacting object, however, an understanding of the extent of the damage due to an impact is required so that if one should occur in practice an assessment can be made to determine if remedial action needs to be taken to ensure that the pipeline is still serviceable. There are a number of parameters, including the pipe cross section and impact energy, which influence the impact behaviour of a pipe. This paper describes the response, and assesses the damage, of mild steel pipes under high mass low velocity impacts. For this purpose full scale impacts tests were carried out on mild steel pipe having diameter of 457 mm, thickness of 25.4 mm and length of 2000 mm. The pipe was restrained along the base and a 2 tonnes mass with sharp impactor having a vertical downward velocity of 3870 mm/sec was used to impact the pipe transversely with an impact energy of 16 kJ. It was found from the impact tests that a smooth indentation was produced in the pipe. The impact tests were then used for validation of the non-linear dynamic implicit analyses using the finite element analysis software ABAQUS. Deformations at the impact zone, the rebound velocity, etc, recorded in the tests and the results of the finite element analysis were found to be in good agreement. The impact tests and finite element analyses described in this paper will help to improve the understanding of the response of steel pipes under impact loading and can be used as a benchmark for further finite element modelling of impacts on pipes.

Sign in / Sign up

Export Citation Format

Share Document