scholarly journals A self-adjusting stiffness center design for large stroke compliant XY nanomanipulators

2018 ◽  
Vol 9 (1) ◽  
pp. 41-50 ◽  
Author(s):  
Zhiqing Liu ◽  
Zhen Zhang ◽  
Peng Yan
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Geometric Parameters ◽  
Rotational Stiffness ◽  
Element Analysis ◽  
Redundant Constraint ◽  
Alternative Approach ◽  
Motion Stage ◽  
The Moment

Abstract. In the present paper, it is proposed a self-adjusting stiffness center (SASC) design for large stroke XY beam flexure-based mechanisms. An important feature of the SASC lies in it restricts the in-plane parasitic rotation by reducing the moment of force instead of increasing the rotational stiffness widely utilized in the literature. Specifically, it is shown that by leveraging on the varied stiffness of the parallelogram flexure, the stiffness center can be made stationary by appropriately setting the relevant geometric parameters, so that the parasitic rotation can be restricted. Furthermore, it is presented a millimeter stroke XY nanomanipulator with the SASC-based redundant constraint in a case study. Numerous finite element analysis (FEA) results demonstrate that the proposed design is not only capable of achieving 1.5 × 1.5 mm2 working range in a compact desktop size, but significantly reduces the in-plane moment applied to the motion stage. The proposed SASC-based design provides an alternative approach to reduce the parasitic rotation of large stroke XY beam flexure-based mechanisms.

scholarly journals Finite element analysis of village car pickup ladder frame chassis- a case study

2021 ◽  
Vol 700 (1) ◽  
pp. 012008
Author(s):  
Ahmad Roziqin ◽  
Kriswanto ◽  
W Aryadi
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Element Analysis

Experimental and finite element analysis of surgical drill bits with and without irrigation channel – A case study approach

2018 ◽  
Vol 62 ◽  
pp. 29-35 ◽  
Author(s):  
Zoran Domitran ◽  
Danko Brezak ◽  
Tomislav Staroveski ◽  
Miho Klaic ◽  
Tomislav Bruketa
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Case Study Approach ◽  
Element Analysis ◽  
Study Approach ◽  
Irrigation Channel ◽  
Drill Bits

Design and Analysis of a Miniaturization Nanoindentation and Scratch Device

2011 ◽  
Vol 314-316 ◽  
pp. 1792-1795
Author(s):  
Hu Huang ◽  
Hong Wei Zhao ◽  
Jie Yang ◽  
Shun Guang Wan ◽  
Jie Mi ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Amorphous Alloy ◽  
Natural Frequencies ◽  
Geometric Parameters ◽  
Flexure Hinge ◽  
Element Analysis ◽  
Modal Characteristics

In this paper, a miniaturization nanoindentation and scratch device was developed. Finite element analysis was carried out to study static and modal characteristics of x/y flexure hinge and z axis driving hinge as well as effect of geometric parameters on output performances of z axis driving hinge. Results indicated that x/y flexure hinge and z axis driving hinge had enough strength and high natural frequencies. Geometric parameters of z axis driving hinge affected output performances significantly. The model of developed device was established. Indentation experiments of Si and amorphous alloy showed that the developed miniaturization nanoindentation and scratch device worked well and can carry out indentation experiments with certain accuracy.

scholarly journals Stiffness prediction for bolted moment-connections in cold-formed steel trusses

2020 ◽  
Vol 41 (1) ◽  
Author(s):  
Apai Benchaphong ◽  
Rattanasak Hongthong ◽  
Sutera Benchanukrom ◽  
Nirut Konkong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Analytical Method ◽  
Truss Structures ◽  
Rotational Stiffness ◽  
Element Analysis ◽  
Moment Connection ◽  
Rigid Connection ◽  
Cold Formed Steel ◽  
Steel Trusses

The purpose of this research was to study the behavior of cold-formed steel cantilever truss structures. A cantilever truss structure and bolt-moment connection were tested and verified by the 3D-finite element model. The verification results showed a good correlation between an experimental test and finite element analysis. An analytical method for elastic rotational stiffness of bolt-moment connection was proposed. The equation proposed in the analytical method was used to approximate the elastic rotational stiffness of the bolt group connection, and was also applied to the Richard-Abbott model for generating the nonlinear moment-rotation curve which modeled the semi-rigid connection stiffness. The 2D-finite element analysis was applied to study the behavior of the truss connection, caused by semi-rigid connection stiffness which caused a change of force to the truss elements. The results showed that the force in the structural members increased by between 13.62%-74.32% of the axial forces, and the bending moment decreased by between 33.05%-100%. These results strongly suggest that the semi-rigid connection between cold-formed steel cantilever truss structures should be considered in structural analysis to achieve optimum design, acknowledging this as the real behavior of the structure.

Design and Analysis of Manufacturing Component Under Sustainability Considerations: A Case Study of Electronic and Mechanical Indexing Head for Milling Operation

2018 ◽  
Author(s):  
Nand K. Jha ◽  
Mahmoud M. Amin
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Cost Estimation ◽  
Minimum Energy ◽  
Solid Modeling ◽  
Milling Machine ◽  
Element Analysis ◽  
Milling Operation ◽  
The Cost

An attempt has been made to design and analyze Indexing Head a very important component in milling operation under sustainability considerations. The design of each component of indexing head is presented along with solid modeling and finite element analysis. The cost estimation for indexing head for milling operation is also presented. The design and finite element analysis of indexing head should be utilized by manufacturers of this very useful device in milling operation. It is used for cutting gears, spirals, splines, etc. The cost estimated of the manufactured indexing head shows it to be within reasonable limits of market. Finite element analysis of each component is safe. An electronic indexing is suggested as an improvement over the mechanical indexing head. A schematic of electronic indexing is presented. The electronic indexing head can be used with milling machine not provided with indexing head and will be portable. The minimum energy needed to manufacture the indexing head is also estimated.

A Review of Optimising the Design of a New Coke Drum Skirt

2019 ◽  
Author(s):  
Alex Berry ◽  
Warren Brown ◽  
Antonio Seijas ◽  
Sarah Cook
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Fatigue Life ◽  
Literature Review ◽  
Thermal Stresses ◽  
Fatigue Cracking ◽  
Element Analysis ◽  
Long Life ◽  
Welded Connection

Abstract Coke drums are subjected to severe thermal cycling with the skirt to shell connection weld being vulnerable to fatigue cracking. It is essential this connection is well designed to ensure a long life before repairs are inevitably required. Much has been written on coke drum skirt design with the aim of reducing the thermal stresses and strains encountered at the skirt connection weld, some designs have removed the weld completely allowing the drum to sit in an “egg-in-cup” arrangement. This paper includes a short literature review discussing Coke drum skirt designs and explains skirt behaviour during the drum cycle that results in eventual skirt cracking. A case study is reviewed in detail for a new pair of coke drums, where the predicted fatigue life of the chosen welded connection is assessed using axisymmetric, quarter symmetry and half symmetry finite element analysis supported by thermocouple data. The optimised design focuses on a conventional tangential design where the effects of the essential variables such as skirt thickness, skirt connection location, skirt-to head-gap and slot design (length, location & spacing) have been modelled and optimised to obtain a skirt design that produces the longest fatigue life for the intended duty cycle. Coke drum skirts must be installed onto the shell to exacting tolerances during manufacture to ensure concentricity and minimal gap between the skirt and shell. A brief overview of how this is achieved will be presented.

scholarly journals Long-Term Performance of Trestle Bridges: Case Study of an Indonesian Marine Port Structure

2020 ◽  
Vol 8 (5) ◽  
pp. 358 ◽  
Author(s):  
Yusak Oktavianus ◽  
Massoud Sofi ◽  
Elisa Lumantarna ◽  
Gideon Kusuma ◽  
Colin Duffield
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Service Life ◽  
Field Measurement ◽  
Field Measurements ◽  
Element Analysis ◽  
Moment Capacity ◽  
Non Destructive

A precast reinforced concrete (RC) T-beam located in seaport Terminal Peti Kemas (TPS) Surabaya built in 1984 is used as a case study to test the accuracy of non-destructive test techniques against more traditional bridge evaluation tools. This bridge is mainly used to connect the berth in Lamong gulf and the port in Java Island for the logistic purposes. The bridge was retrofitted 26 years into its life by adding two strips of carbon fiber reinforced polymer (CFRP) due to excessive cracks observed in the beams. Non-destructive field measurements were compared against a detailed finite element analysis of the structure to predict the performance of the girder in terms of deflection and moment capacity before and after the retrofitting work. The analysis was also used to predict the long-term deflections of the structure due to creep, crack distribution, and the ultimate moment capacity of the individual girder. Moreover, the finite element analysis was used to predict the deflection behavior of the overall bridge due to vehicle loading. Good agreement was obtained between the field measurement and the analytical study. A new service life of the structure considering the corrosion and new vehicle demand is carried out based on field measurement using non-destructive testing. Not only are the specific results beneficial for the Indonesian port authority as the stakeholder to manage this structure, but the approach detailed also paves the way for more efficient evaluation of bridges more generally over their service life.

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