Design of a Multi-Contact-Aided Compliant Mechanism

2011 ◽  
Author(s):  
Milton E. Aguirre ◽  
Mary Frecker
Keyword(s):  
Contact Stress ◽  
Compliant Mechanism ◽  
Stress Relief ◽  
Surgical Instruments ◽  
End User ◽  
Forming Process ◽  
Finite Element Software ◽  
Multi Stage ◽  
Jaw Opening

This work is part of a multidisciplinary project developing design and manufacturing methods for narrow-gauge surgical instruments intended for advanced minimally invasive surgery. The instruments are designed specifically for Penn State’s lost mold rapid infiltration forming process, which is capable of fabricating hundreds of freestanding meso-scale parts. In previous work, a 1 mm diameter forceps case study demonstrated the design and fabrication process. The forceps is a monolithic compliant mechanism (CM) that relies on contact to re-distribute maximum stresses to generate larger elastic tip deflections; a phenomenon defined here as contact stress-relief. Prototypes were developed and evaluated in an end user surgical simulator. Feedback from 11 clinicians identified the total jaw opening of the forceps must be increased in the next generation of prototypes. This paper focuses on exploiting the benefits of contact-aided compliant mechanism (CCM) design to obtain larger elastic tip deflections and thus jaw openings. Using the commercially available finite element software package ANSYS to model large deformation and contact, an optimization problem is developed to determine the effects of incorporating additional contact elements in a CCM design on maximizing elastic tip deflection. Results show that designs with multiple contact elements generate larger elastic tip deflections due to a multi-stage contact stress-relief profile.

scholarly journals Using Design Thinking Principles to Improve Outpatients’ Experiences in Hospital Pharmacies: A Case Study of Two Hospitals in Asir Region, Saudi Arabia

Healthcare ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 854
Author(s):  
Dalia Almaghaslah ◽  
Abdulrhman Alsayari ◽  
Saleh Ali Alyahya ◽  
Rana Alshehri ◽  
Khawlah Alqadi ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Problem Solving ◽  
Management System ◽  
Design Thinking ◽  
Queue Management ◽  
End User ◽  
Study Results ◽  
Hospital Pharmacies ◽  
Asir Region

Introduction: Design thinking, an innovative problem-solving approach, has gained wide popularity in healthcare disciplines. The aim of this work is to improve outpatients’ experiences in hospital pharmacies in two hospitals in Asir region, Saudi Arabia. Methods: The design thinking approach, adopted from Stanford University’s D-School, was used in this study. Results: Several problems were identified: lack of comfortable environment in the pharmacies’ waiting area, lack of a queue management system, and workflow inefficiencies related to ordering and supplies of medicines. A prototype was proposed to overcome these challenges. Discussion and Conclusion: The design thinking approach helped in identifying end-user (patients visiting outpatient pharmacies) values and desires and provided an understanding of their struggles. It also proposed tailored solutions that could improve patients’ experiences while using the services of the outpatient pharmacies.

End-User Robot Programming Case Study

2020 ◽  
Author(s):  
Michal Kapinus ◽  
Zdeněk Materna ◽  
Daniel Bambušek ◽  
Vitězslav Beran
Keyword(s):  
Robot Programming ◽  
End User

scholarly journals Plastic forming processes of transverse non-homogeneous composite metallic sheets

2021 ◽  
Vol 11 (1) ◽  
pp. 294-302
Author(s):  
Gal Davidi
Keyword(s):  
Inner Core ◽  
Plastic Material ◽  
Radial Solution ◽  
Algebraic Differential Equation ◽  
Forming Process ◽  
Perfectly Plastic ◽  
Plastic Forming ◽  
Validity Limit ◽  
Significant Achievement

Abstract In this work an analysis of the radial stress and velocity fields is performed according to the J 2 flow theory for a rigid/perfectly plastic material. The flow field is used to simulate the forming processes of sheets. The significant achievement of this paper is the generalization of the work by Nadai & Hill for homogenous material in the sense of its yield stress, to a material with general transverse non-homogeneity. In Addition, a special un-coupled form of the system of equations is obtained where the task of solving it reduces to the solution of a single non-linear algebraic differential equation for the shear stress. A semi-analytical solution is attained solving numerically this equation and the rest of the stresses term together with the velocity field is calculated analytically. As a case study a tri-layered symmetrical sheet is chosen for two configurations: soft inner core and hard coating, hard inner core and soft coating. The main practical outcome of this work is the derivation of the validity limit for radial solution by mapping the “state space” that encompasses all possible configurations of the forming process. This configuration mapping defines the “safe” range of configurations parameters in which flawless processes can be achieved. Several aspects are researched: the ratio of material's properties of two adjacent layers, the location of layers interface and friction coefficient with the walls of the dies.

The Kinematics Analysis and Study on Triangular Elbow Servo Press

2011 ◽  
Vol 121-126 ◽  
pp. 1636-1640
Author(s):  
Ying Qiu ◽  
Wei Min Li ◽  
Zhi Wei
Keyword(s):  
Optimization Design ◽  
Research Field ◽  
Transmission Mechanism ◽  
Kinematics Analysis ◽  
Servo Motor ◽  
Forming Process ◽  
Servo Press ◽  
Heavy Haul ◽  
Slider Motion

Servo presses are widely used in high-precision, complicated forming process fields and promoted around the world in recent years. It is the trend of forging machinery for its servo motor-based digital heavy haul driven technology. At present, it becomes the hot research field. The structure characteristics of triangular elbow servo press were firstly introduced in the paper. And then the kinematics mathematical model of triangular elbow transmission mechanism was deduced and given. Based on it, this paper provides the slider kinematics analysis by Matlab. The slider motion law under various parameters can be analyzed and compared. The results would be useful reference for optimization design of transmission mechanism. The case study provides more visual and reliable decision basis for designer.

Analysis on Temperature Field of Work-Piece during Cross Wedge Rolling

2011 ◽  
Vol 230-232 ◽  
pp. 352-356
Author(s):  
Wen Ke Liu ◽  
Kang Sheng Zhang ◽  
Zheng Huan Hu
Keyword(s):  
Finite Element ◽  
Temperature Field ◽  
Metal Flow ◽  
Work Piece ◽  
Contact Deformation ◽  
Cross Wedge Rolling ◽  
Forming Process ◽  
Rigid Plastic ◽  
Finite Element Software ◽  
Deform 3D

Based on the rigid-plastic deformation finite element method and the heat transfer theories, the forming process of cross wedge rolling was simulated with the finite element software DEFORM-3D. The temperature field of the rolled piece during the forming process was analyzed. The results show that the temperature gradient in the outer of the work-piece is sometimes very large and temperature near the contact deformation zone is the lowest while temperature near the center of the rolled-piece keeps relatively stable and even rises slightly. Research results provide a basis for further study on metal flow and accurate shaping of work-piece during cross wedge rolling.

Milling Curves Influence in Ring Rolling Processes

2014 ◽  
Vol 622-623 ◽  
pp. 956-963 ◽  
Author(s):  
Luca Giorleo ◽  
Elisabetta Ceretti ◽  
Claudio Giardini
Keyword(s):  
Numerical Approach ◽  
The Other ◽  
Ring Rolling ◽  
Roll Speed ◽  
Forming Process ◽  
Industrial Case Study ◽  
Industrial Environment ◽  
Ring Shape ◽  
Deformation Processes

Ring Rolling is a complex hot forming process used for the production of shaped rings, seamless and axis symmetrical workpieces. The main advantage of workpieces produced by ring rolling, compared to other technological processes, is given by the size and orientation of grains, especially on the worked surface which give to the final product excellent mechanical properties. In this process different rolls (Idle, Axial, Guide and Driver) are involved in generating the desired ring shape. Since each roll is characterized by a speed law that can be set independently by the speed law imposed to the other rolls, an optimization is more critical compared with other deformation processes. Usually, in industrial environment, a milling curve is introduced in order to correlate the Idle and Axial roll displacement, however it must be underlined that different milling curves lead to different loads and energy for ring realization. In this work an industrial case study was modeled by a numerical approach: different milling curves characterized by different Idle and Axial roll speed laws (linearly decreasing, constant, linearly increasing) were designed and simulated. The results were compared in order to identify the best milling curve that guarantees a good quality ring (higher diameter, lower fishtail) with lower loads and energy required for manufacturing.

scholarly journals Son-of-God traditions in the Synoptic Gospels: Ferdinand Hahn's diachronic perspective

2001 ◽  
Vol 57 (1/2) ◽  
Author(s):  
Yolanda Dreyer
Keyword(s):  
Early Christianity ◽  
Synoptic Gospels ◽  
Son Of God ◽  
Multi Stage ◽  
Stage Development ◽  
Hellenistic Judaism ◽  
Cultural World ◽  
Historical Origins

This study makes use of Ferdinand Hahn's insights (with Son of God as case study) to indicate how the naming of Jesus developed in stages. It is shown that the name Son of God was not used by Jesus. It functioned within the context of the cultic activities of early Christianity, was taken over from the surrounding religious, political and cultural world while its referential meaning shifted in the various layers. Hahn focuses on the multi-stage development of the Jesus tradition from an Aramaic "Judaism", through  a Hellenistic "Judaism" to a Gaeco-Roman stage. First the possible historical origins of the title Son of God are discussed, after which Hahn's view is taken into consideration.

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