The Development of a Microscale Tube Hydroforming Test Bed and Novel Sealing System: A Work in Progress

2019 ◽  
Author(s):  
William J. Emblom ◽  
Ayotunde Olayinka ◽  
Scott W. Wagner
Keyword(s):  
Tube Hydroforming ◽  
Cnc Machining ◽  
Test Bed ◽  
Pressure System ◽  
System A ◽  
Hydroforming Process ◽  
University Of Louisiana ◽  
Machining Operations ◽  
The University ◽  
Technological University

Abstract A microscale/multiscale tube hydroforming system including tooling and controls is being designed and implemented at the University of Louisiana at Lafayette as part of a collaborative effort with Michigan Technological University. The sealing system demonstrates the evolution of the flared tube ends approach for tube end sealing to a spherical metal-on-metal sealing system. One of the features of the tooling is that while the tooling is capable of producing microscale hydroforming, the entire system can now be made using conventional CNC machining operations. Preliminary work has begun for implementing control of the hydroforming process using a PLC and a custom built continuous high pressure system capable of 415 MPa is described. Preliminary results for formed sample tubes are discussed.

Introduction of a quality management system compliant with DIN EN ISO 9001:2000 into a university department of nuclear medicine

2001 ◽  
Vol 40 (06) ◽  
pp. 228-238 ◽  
Author(s):  
U. Paschen ◽  
S. Kröger ◽  
K. H. Bohuslavizki ◽  
M. Clausen ◽  
V. Jansen-Schmidt
Keyword(s):  
Nuclear Medicine ◽  
Quality Management System ◽  
Iso 9001 ◽  
Total Quality ◽  
System A ◽  
General Rules ◽  
Therapeutic Procedures ◽  
University Department ◽  
Referring Physicians ◽  
The University

SummaryIn 1995, the management of the University Clinic Hamburg-Eppendorf proposed to establish a total quality assurance (QA) system. A revised QA-system has been introduced stepwise in the department of nuclear medicine since 1997, and certification was achieved in accordance with DIN EN ISO 9001:2000 on February 14,2001.The QA-handbook is devided into two parts. The first part contains operational (diagnostic and therapeutic) procedures in so-called standard operating procedures (SOP). They describe the indication of procedures as well as the competences and time necessary in a standardized manner. Up to now, more than 70 SOPs have been written as a collaborative approach between technicians and physicians during daily clinical routine after analysing and discussing the procedures. Thus, the results were more clearly defined processes and more satisfied employees.The second part consists of general rules and directions concerning the security of work and equipment as well as radialion protection tasks, hygiene etc. as it is required by the law. This part was written predominantly by the management of the department of nuclear-medicine and the QA-coordinator. Detailed information for the patients, documentation of the work-flows as well as the medical report was adapted to the QM-system. Although in the introduction phase of a QA-system a vast amount of time is necessary, some months later a surplus for the clinical workday will become available. The well defined relations of competences and procedures will result in a gain of time, a reduction of costs and a help to ensure the legal demands. Last but not least, the QA-system simply helps to build up confidence and acceptance both by the patients and the referring physicians.

Optimization of Tube Hydroforming Process Using Probabilistic Constraints on Failure Modes

2011 ◽  
Vol 62 ◽  
pp. 21-35 ◽  
Author(s):  
Anis Ben Abdessalem ◽  
A. El Hami
Keyword(s):  
Failure Modes ◽  
High Reliability ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Forming Limit Diagram ◽  
Plastic Instability ◽  
Probabilistic Constraints ◽  
Forming Limit ◽  
Reliability Based Design ◽  
Hydroforming Process

In metal forming processes, different parameters (Material constants, geometric dimensions, loads …) exhibits unavoidable scatter that lead the process unreliable and unstable. In this paper, we interest particularly in tube hydroforming process (THP). This process consists to apply an inner pressure combined to an axial displacement to manufacture the part. During the manufacturing phase, inappropriate choice of the loading paths can lead to failure. Deterministic approaches are unable to optimize the process with taking into account to the uncertainty. In this work, we introduce the Reliability-Based Design Optimization (RBDO) to optimize the process under probabilistic considerations to ensure a high reliability level and stability during the manufacturing phase and avoid the occurrence of such plastic instability. Taking account of the uncertainty offer to the process a high stability associated with a low probability of failure. The definition of the objective function and the probabilistic constraints takes advantages from the Forming Limit Diagram (FLD) and the Forming Limit Stress Diagram (FLSD) used as a failure criterion to detect the occurrence of wrinkling, severe thinning, and necking. A THP is then introduced as an example to illustrate the proposed approach. The results show the robustness and efficiency of RBDO to improve thickness distribution and minimize the risk of potential failure modes.

scholarly journals Numerical investigation of plastic flow and residual stresses generated in hydroformed tubes

2021 ◽  
pp. 146442072198974
Author(s):  
A Ktari ◽  
A Abdelkefi ◽  
N Guermazi ◽  
P Malecot ◽  
N Boudeau
Keyword(s):  
Finite Element ◽  
Residual Stresses ◽  
Finite Element Model ◽  
Plastic Flow ◽  
Tube Hydroforming ◽  
Three Dimensional ◽  
Element Model ◽  
Tube Cross Section ◽  
Straight Wall ◽  
Hydroforming Process

During tube hydroforming process, the friction conditions between the tube and the die have a great importance on the material plastic flow and the distribution of residual stresses of the final component. Indeed, a three-dimensional finite element model of a tube hydroforming process in the case of square section die has been performed, using dynamic and static approaches, to study the effect of the friction conditions on both plastic flow and residual stresses induced by the process. First, a comparative study between numerical and experimental results has been carried out to validate the finite element model. After that, various coefficients of friction were considered to study their effect on the thinning phenomenon and the residual stresses distribution. Different points have been retained from this study. The thinning is located in the transition zone cited between the straight wall and the corner zones of hydroformed tube due to the die–tube contact conditions changes during the process. In addition, it is clear that both die–tube friction conditions and the tube bending effects, which occurs respectively in the tube straight wall and corner zones, are the principal causes of the obtained residual stresses distribution along the tube cross-section.

Experimental Researches upon Changes of a Pipe's Roughness after Hydroformation

2013 ◽  
Vol 371 ◽  
pp. 111-115
Author(s):  
Bogdan Constantin Vaceanu ◽  
Gheorghe Nagit ◽  
Vasile Huian
Keyword(s):  
Surface Roughness ◽  
Tube Hydroforming ◽  
Work Piece ◽  
Copper Pipe ◽  
Work Area ◽  
The Coefficient Of Friction ◽  
Hydroforming Process ◽  
Aluminum Pipe ◽  
Experimental Researches

Surface roughness was studied in the tube hydroforming process, considering the quality of the material and the coefficient of friction between the work piece and die. Other researchers have studied the surface roughness to the front of an aluminum pipe [. The aim of this work was to analyze changes in a copper pipe roughness occurred after hydroforming process with fluid. Effects of changing roughness were studied, following the deformation of the material in the work area and roughness changes occurring in the material flow. After achieving hydroforming process, the surface roughness was measured by electron microscopy SEM in different areas of the hydro formed tube. After hydroforming process, an increase of surface roughness in connection areas of the mold to the curvature and the transverse direction of the pipe.

scholarly journals A Review of Recent Application of Machining Techniques, based on the Phenomena of CNC Machining Operations

2019 ◽  
Vol 35 ◽  
pp. 1054-1060 ◽  
Author(s):  
I.P. Okokpujie ◽  
C.A. Bolu ◽  
O.S. Ohunakin ◽  
E.T. Akinlabi ◽  
D.S. Adelekan
Keyword(s):  
Cnc Machining ◽  
Recent Application ◽  
Machining Operations

scholarly journals Perceptions of organisational readiness for the performance management system: A case study of a University of technology

2012 ◽  
Vol 8 (3) ◽  
pp. 39-47
Author(s):  
Bethuel Sibongiseni Ngcamu
Keyword(s):  
Performance Management ◽  
Management System ◽  
Quantitative Research ◽  
Business Processes ◽  
Survey Method ◽  
Performance Management System ◽  
System A ◽  
Management Interventions ◽  
University Of Technology ◽  
The University

The absence of a single performance management system (PMS) aligned to institutional strategy and business processes often results in failure to deliver anticipated benefits as it is not cascaded down to all departments, teams or individuals. This study aims to determine employees’ expectations for the proposed PMS and their perceptions of the system’s impact on effectiveness within the university concerned. This study adopted a quantitative research design and a survey method was used, whereby, a structured questionnaire was administered by the researcher to a selected population size of 150 of which 108 completed questionnaires, generating a response rate of 72%. The study reflects a disproportionately high percentage of 34% of the respondents who disagreed and 21.3% who were undecided as to whether PMS is needed at the university concerned where the majority of these respondents being academics and those with matriculation. The university concerned should develop a PMS which is aligned to the university strategic plan and to other university policies coupled with structured change management interventions focusing on academics and semi-skilled employees.

scholarly journals Predictors of Users’ Satisfaction with E-payment System: a Case Study of Staff at the University of Ilorin, Nigeria

Organizacija ◽  
2015 ◽  
Vol 48 (4) ◽  
pp. 272-286 ◽  
Author(s):  
Adeyinka Tella ◽  
Isah Abdulmumin
Keyword(s):  
Design Methodology ◽  
Academic Staff ◽  
Payment System ◽  
Research Approach ◽  
System A ◽  
Order Of Magnitude ◽  
Research Questions ◽  
The University ◽  
Perceived Speed

Abstract Background and Purpose: Many organisations are using the e-payment system; however, its effectiveness has not been determined particularly in the Nigeria context. The University of Ilorin as educational organisation started using e-payment system in 2010 and up till now there has been limited or no study conducted to examine whether or not workers are satisfied with the new payment system together with other related ones they are familiar with. It is in the light of this that this study examined users’ satisfaction with the e-payment system at the University of Ilorin, Nigeria. Design/Methodology/Approach: A sample of 260 academic and non-academic staff was taken from six out 12 faculties that made up the university. Using a survey research approach data was collected with a modified questionnaire. Five research questions were developed to guide the study. Results: The results revealed that, respondents (93.5%) were adequately satisfied, satisfied and moderately satisfied, while, only (6.5%) of the respondents were less satisfied and dissatisfied. Perceived speed was identified as the characteristics users mostly satisfied with, followed by system security, traceability, and convenience. Moreover, there is significant correlation among the entire e-payment characteristics/factors (perceived speed, security, anonymity, traceability, perceived ease of payment, and convenience); and that all the six factors jointly predict users’ satisfaction with the e-payment system. In order of magnitude of the prediction/contribution to e-payment, users’ satisfaction, perceived speed made the most significant prediction/contribution. Conclusion: Based on the findings, the study concluded a considerable percentage of the respondents (93.5%) are satisfied with the e-payment system at the University of Ilorin, Nigeria. In lieu of this therefore, there is need to improve the e-payment system so that all and sundry could be satisfied.

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