Nondestructive Measures of Structural Integrity in Powder Metal Parts Using Resonance -- Case Study

2001 ◽  
Author(s):  
Patrick M. Bowen
Keyword(s):  
Structural Integrity ◽  
Resonance Case ◽  
Powder Metal ◽  
Metal Parts

scholarly journals Does Tenure Security Reduce Disaster Risk? A Comparative Study of the Nairobi Settlements of Kibera and Kawangware

2021 ◽  
Author(s):  
Rónán McDermott ◽  
Pat Gibbons ◽  
Dalmas Ochieng ◽  
Charles Owuor Olungah ◽  
Desire Mpanje
Keyword(s):  
Structural Integrity ◽  
Disaster Risk ◽  
Comparative Case Study ◽  
Complex Relationship ◽  
Tenure Security ◽  
Household Level ◽  
Urban Informal Settlements ◽  
The Relationship

AbstractWhile scholarship suggests that improving tenure security and housing significantly reduces disaster risk at the household level within urban settings, this assertion has not been adequately tested. Tenure security can be conceived as being composed of three interrelated and overlapping forms: tenure security as determined by legal systems; de facto tenure security; and tenure security as perceived by residents. This article traces the relationship between tenure security, the quality of housing, and disaster risk on the basis of a mixed methods comparative case study of the settlements of Kawangware and Kibera in Nairobi. Although the findings suggest that owner-occupancy is associated with the structural integrity of dwellings to a greater extent than tenantship, no association was found between the length of occupancy by households and the structural integrity of the dwelling. Moreover, tenantship is not found to be closely associated with fires and flooding affecting the dwelling as extant scholarship would suggest. Formal ownership is linked with greater investment and upgrading of property with significant implications for disaster risk. Our findings highlight the complex relationship between tenure security and disaster risk in urban informal settlements and provide impetus for further investigation.

Effect of Porosity Content on the Weldability of Powder Metal Parts Produced by Friction Stir Welding

2007 ◽  
Vol 534-536 ◽  
pp. 789-792 ◽  
Author(s):  
Adem Kurt ◽  
Ilyas Uygur ◽  
Hakan Ates
Keyword(s):  
Friction Stir Welding ◽  
Powder Metal ◽  
Aluminum Powders ◽  
Friction Stir ◽  
Metal Parts ◽  
Constant Friction ◽  
Sintered Powder ◽  
Hardness Values ◽  
Welding Technique ◽  
Traveling Speed

Friction stir welding technique (FSW) has many advantages in terms of tool design, rotational speed and traveling speed, and can be adjusted in a precise manner. It enables heat input into the system to be controlled. In this study, Aluminum powders were compacted at 350,400 and 450 MPa pressure and sintered at 450 oC temperature for 30 minutes in Ar atmosphere. Sintered powder metal parts were joined to each other by FSW at the speed of 1800 rpm and traveling welding speed 200 mm/min under a constant friction force. The results show that the amount of porosity affects the weldability of powder metallurgy (P/M) parts. Furthermore, the porosity and microstructural evolution of the Aluminum also affected the hardness values of the tested materials.

scholarly journals Residual Life Assessment of Electricity Pylons – A Case Study

2009 ◽  
Vol 413-414 ◽  
pp. 219-228 ◽  
Author(s):  
John R. Maguire
Keyword(s):  
Structural Integrity ◽  
Residual Life ◽  
Life Assessment ◽  
Original Design ◽  
Integrity Assessment ◽  
Specific Safety ◽  
Residual Life Assessment ◽  
Independent Assessment ◽  
Overhead Power Line

This case study describes a structural integrity assessment of a 220 kV overhead power line. The line comprises 70 pylons over a distance of approximately 30 km, predominantly in a valley location. The pylons are spaced at intervals of approximately 400 m and each pylon is approximately 32 m in height. The line was originally constructed in the 1950’s, approximately 50 years prior to the requested structural integrity assessment. This paper describes the independent assessment that was carried out. The review established site-specific safety factors at the time of original design and construction; at the time of the review (2007), accounting for the possible presence of the “Thomasstahl” steel; and in the future, at the anticipated end of pylon life (in 2012).

Using Symmetry to Reduce Planning Complexity: A Case Study in Sheet-Metal Production

1997 ◽  
Author(s):  
Cheng-Hua Wang ◽  
David A. Bourne
Keyword(s):  
Sheet Metal ◽  
Detection Algorithm ◽  
Assembly Planning ◽  
Product Decomposition ◽  
Metal Production ◽  
Layout Planning ◽  
Significant Percentage ◽  
Metal Parts ◽  
Sheet Metal Parts

Abstract In this paper, we present an approach to recognize symmetries of bent sheet-metal parts at different manufacturing stages. This approach is based on Waltzman’s (Waltzman, 1987) 2D symmetry detection algorithm. 3D symmetry is recognized by considering its 2D symmetry and the associated bending transformations. We show, by recognizing that the part is symmetrical, that the planning complexity for processes in sheet-metal production can be greatly reduced. This paper is motivated by the fact that a significant percentage of sheet-metal parts are symmetrical. We have studied over 200 industrial parts and over 40% of them are symmetrical. Examples from sheet-metal nesting (layout planning), bending, stacking, product decomposition and assembly planning are discussed.

Floatover Deck Installation: Case Study — Structural Efficiency of Longitudinally and Transversely-Recessed Structures

2004 ◽  
Author(s):  
Lee A. O’Neill ◽  
Emmanuel Fakas ◽  
Rodney Pinna ◽  
Timothy Walsh
Keyword(s):  
Transverse Direction ◽  
Structural Integrity ◽  
Structural Performance ◽  
Structural Efficiency

Conventional floatover deck (FOD) installation on a jacket substructure requires the top of the structure to be recessed appropriately, either in the longitudinal or transverse direction to accommodate the vessel transporting the deck. The recess direction is very important to the design of the jacket and influences the outfitting of appurtenances, the shape of the deck and the floatover concept as a whole. This study investigates the structural integrity of typical longitudinal and transverse jackets suitable for FOD installation under both inplace and installation conditions. The study also assesses the structural efficiency of the two options under various installation conditions and benchmarks their structural performance against more conventional jackets associated with lift-installed decks.

Long Term Structural Integrity Considerations for Abandoned Pipelines

2016 ◽  
Author(s):  
Shane Finneran ◽  
T. J. Prewitt ◽  
Joel Kaufman
Keyword(s):  
Transmission Lines ◽  
Structural Integrity ◽  
Large Diameter ◽  
Metal Loss ◽  
Finite Element Analyses ◽  
Load Bearing Capacity ◽  
Soil Subsidence ◽  
Structural Capacity

There has been increasing interest across the industry to better understand the possible long term risks associated with out of service pipelines. In Canada, the Canadian Energy Pipeline Association (CEPA), Petroleum Technology Alliance of Canada (PTAC), and the National Energy Board (NEB), have undertaken multiple studies to identify and assess the threats related to pipeline abandonment. [1][2][3] The primary hazards typically identified across industry for pipeline abandonment are associated with long term corrosion degradation, potential for creation of water conduits, possible environmental impacts, and potential for pipeline collapse and associated soil subsidence. Unfortunately, little guidance is presently available to the industry for determining remaining structural capacity of a heavily corroded pipeline to establish likelihood, and possible timeline, of collapse, nor for determining possible subsidence magnitudes associated with large diameter transmission lines. This paper presents a technical case study for an assessment approximating the remaining strength of an abandoned pipeline subject to long term corrosion degradation, considering both general metal loss, and randomized pitting and perforation growth. The work presented used a combination of finite element analyses, and existing industry models for determining load bearing capacity of an abandoned pipeline under varying levels of degradation.

AE Damage Assessment in the Bell Tower of the Turin Cathedral

2019 ◽  
Vol 817 ◽  
pp. 579-585
Author(s):  
Amedeo Manuello ◽  
Davide Masera ◽  
Alberto Carpinteri
Keyword(s):  
Damage Assessment ◽  
Structural Integrity ◽  
Cumulative Number ◽  
Height Ratio ◽  
Value Analysis ◽  
Integrity Assessment ◽  
Bell Tower ◽  
The Stability ◽  
Good Agreement

Historical churches, masonry towers and bell towers are structures subjected to high risk, due to their age, elevation and low base area on height ratio. In this work, an innovative monitoring technique for structural integrity assessment of historical buildings is reported. At the same time, the emblematic case study of the Turin Cathedral Bell tower is presented. The damage evolution in the tall masonry structure is described by the evaluation of the cumulative number of AE and by different parameters able to predict the time dependence of damage. In particular, since environmental disturbances have been minimized, and instrumental noises have been filtered out. The b-value analysis shows a downward trend to values compatible with the growth of localized macro-cracks at the base of the tower. These results seem to be in good agreement with the numerical analysis. Extension to longer monitoring periods and, later, investigation of different segments are strongly recommended to assess the stability of the monument.

Increasing the Structural Integrity of Hybrid Plastics-Metal Parts by an Innovative Mechanical Interlocking Effect

2015 ◽  
Vol 825-826 ◽  
pp. 417-424 ◽  
Author(s):  
Saskia Müller ◽  
Michael Brand ◽  
Klaus Dröder ◽  
Dieter Meiners
Keyword(s):  
Adhesive Bonding ◽  
Structural Integrity ◽  
Tensile Tests ◽  
Limiting Factor ◽  
Full Potential ◽  
Mechanical Interlocking ◽  
Metal Parts ◽  
Dependent Component ◽  
Key Factor ◽  
Mechanical Bonding

In order to exploit full potential of hybrid materials, it is necessary to develop optimized load-dependent component designs, new manufacturing processes and joining technologies. Structural integrity concerning the interfaces between the single materials of the hybrid component poses a key factor to success. In this case, adhesion often constitutes the limiting factor for the maximum transferable load. In this investigation, a load-oriented innovative concept to increase the structural integrity of hybrid plastic-metal parts was developed. Local mechanical undercuts on the metal surface were created to generate an additional mechanical interlocking effect between the join partners. The aim is to find the best surface structure geometry to enhance mechanical bonding. Therefore, metal samples were structured by a new process and transferred to hybrid specimens by injection molding. For comparison, specimens with adhesive bonding (epoxy resin) of metal and plastic were prepared. The join partners aluminum AlCuMg1-2017 and PA6 as well as PA6GF30 were investigated. The evaluation of an increase in the structural integrity was determined using tensile tests. A significant improvement in joint strength compared with direct joining using adhesive bonding was achieved.

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