scholarly journals Weldment to Casting Conversion Using Topology Optimization

2021 ◽  
Vol 9 (8) ◽  
pp. 1309-1319
Author(s):  
Prasad Kulkarni
Keyword(s):  
Topology Optimization ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Dimensional Stability ◽  
Manufacturing Process ◽  
Traditional Method ◽  
Design For Manufacturability ◽  
Final Design ◽  
The Cost ◽  
Casting Design

Abstract: The automobile and off highway industries grapple with dilemma of making a required component out of a weldment by welding different plates together or making a single component using a casting manufacturing process. The decision is always based on many parameters viz. volume of manufactured components, tooling cost involved, dimensional stability required, cost of welding, fatigue strength required etc. As the volume of the manufactured components increases, the cost of casting and its tool goes down and hence it makes sense to convert the weldment into a casting. A traditional method to do this is to convert the weldment into a casting based on functionalities and experience. In this paper, a topology optimization based approach is used to understand and decide the most optimal usage of the material based on the different constraints. In this paper, considerations of weldment to casting conversion, usage of topology optimization to arrive at final design and strength and fatigue life calculation are discussed. Keywords: Weldment, Topology Optimization, casting, Design for Manufacturability

Fatigue Strength of Ribbon Bonds

2010 ◽  
Author(s):  
S. M. Bresney ◽  
A. Saigal
Keyword(s):  
Thermal Expansion ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Manufacturing Process ◽  
Electronic Components ◽  
Mechanical Method ◽  
Temperature Changes ◽  
Life Model ◽  
Short Span ◽  
Different Levels

Ribbon or wire bonding is a common manufacturing process used in the microelectronic industry to make interconnections between electronic components. This process is used because it can make up for misalignment and inconsistent spacing between the components due to tolerance stack ups. In addition, since the ribbons are not rigid they will flex and absorb any stresses that develop when the components expand and contract in the field due to temperature changes. This paper investigates the use of a mechanical method to exercise ribbons in this fashion until they failed. Ribbons of a constant profile but different sizes were exercised at different levels of stress to develop a fatigue life model. It is found that ribbons exercised only a small percentage of their overall span survive exponentially longer than the same ribbons exercised at a higher percentage of their overall span. In addition, at short span lengths relative to the thickness, the ribbon becomes less ‘thread like’ and more stiff. The model developed in this study can be used for designing ribbon size and shape based upon expected thermal expansion cycling and necessary life or reliability.

Deep Rolling Efficiently Increases Fatigue Life

2005 ◽  
Author(s):  
Karsten Ro¨ttger ◽  
Terry L. Jacobs ◽  
Gerhard Wilcke
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Stainless Steels ◽  
Manufacturing Process ◽  
Nickel Alloys ◽  
Lightweight Design ◽  
Surface Zone ◽  
Tool Steels ◽  
Deep Rolling ◽  
Alloy Steels

Deep rolling is a manufacturing process that efficiently increases the fatigue life of dynamically loaded components. It combines three effects to enhance fatigue strength, tribological properties and corrosion of a surface. Deep rolling: • Smoothes the surface; • Induces deep compressive stress in the surface zone; • Work-hardens the surface zone. The technology has developed into a modern, widely applicable process that improves part performance and achieves lightweight design. It has successfully been applied on stainless steels, alloy steels, brass, tool steels, nickel alloys, cast and ductile irons, aluminum, magnesium and titanium alloys [1,2,3].

scholarly journals Fatigue Behavior of Metallic Components Obtained by Topology Optimization for Additive Manufacturing

2020 ◽  
Vol 15 (55) ◽  
pp. 119-135
Author(s):  
Felipe Fiorentin ◽  
Bernardo Oliveira ◽  
João Pereira ◽  
José Correia ◽  
Abilio M.P. de Jesus ◽  
...  
Keyword(s):  
Topology Optimization ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Manufacturing Process ◽  
Fatigue Behavior ◽  
Volume Ratio ◽  
Design Solution ◽  
Component Design ◽  
Final Design ◽  
Smoothing Process

The main goal of the present research is to propose an integrated methodology to address the fatigue performance of topology optimized components, produced by additive manufacturing. The main steps of the component design will be presented, specially the methods and parameters applied to the topology optimization and the post-smoothing process. The SIMP method was applied in order to obtain a lighter component and a suitable stiffness for the desired application. In addition, since residual stresses are intrinsic to every metallic additive manufacturing process, the influence of those stresses will be also analyzed. The Laser Powder Bed Fusion was numerically simulated aiming at evaluating the residual stresses the workpiece during the manufacturing process and to investigate how they could influence the fatigue behavior of the optimized component. The effect of the built orientation of the workpiece on the residual stresses at some selected potential critical points are evaluated. The final design solution presented a stiffness/volume ratio nearly 6 times higher when compared to the initial geometry. By choosing the built orientation, it is possible impact favorably in the fatigue life of the component.

scholarly journals Fatigue Modeling and Numerical Analysis of Re-Filling Probe Hole of Friction Stir Spot Welded Joints in Aluminum Alloys

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2171
Author(s):  
Armin Yousefi ◽  
Ahmad Serjouei ◽  
Reza Hedayati ◽  
Mahdi Bodaghi
Keyword(s):  
Experimental Data ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Behavior ◽  
Element Model ◽  
Plastic Strain Amplitude ◽  
Friction Stir ◽  
Probe Hole ◽  
Good Agreement

In the present study, the fatigue behavior and tensile strength of A6061-T4 aluminum alloy, joined by friction stir spot welding (FSSW), are numerically investigated. The 3D finite element model (FEM) is used to analyze the FSSW joint by means of Abaqus software. The tensile strength is determined for FSSW joints with both a probe hole and a refilled probe hole. In order to calculate the fatigue life of FSSW joints, the hysteresis loop is first determined, and then the plastic strain amplitude is calculated. Finally, by using the Coffin-Manson equation, fatigue life is predicted. The results were verified against available experimental data from other literature, and a good agreement was observed between the FEM results and experimental data. The results showed that the joint’s tensile strength without a probe hole (refilled hole) is higher than the joint with a probe hole. Therefore, re-filling the probe hole is an effective method for structures jointed by FSSW subjected to a static load. The fatigue strength of the joint with a re-filled probe hole was nearly the same as the structure with a probe hole at low applied loads. Additionally, at a high applied load, the fatigue strength of joints with a refilled probe hole was slightly lower than the joint with a probe hole.

Bringing Ergonomics to the Design of a Behavioural Care Unit

2000 ◽  
Vol 44 (8) ◽  
pp. 8-11
Author(s):  
Jacqueline B. Barnett
Keyword(s):  
Design Process ◽  
Iterative Process ◽  
User Needs ◽  
Work Processes ◽  
Team Members ◽  
Early Design ◽  
Design Changes ◽  
Final Design ◽  
The Individual ◽  
The Cost

The application of ergonomics is important when considering the built environment. In order to create an environment where form follows function, a detailed understanding of the tasks performed by the individuals who will live and work in the facility is required. Early involvement in the project is key to maximizing the benefit of ergonomics. At Sunnybrook and Women's College Health Sciences Centre in Toronto, Canada, this early intervention was embraced during the design process of a behavioural care unit for aggressive patients. The ergonomist was involved in three phases of design; user needs analysis, block schematics and detailed design. The user needs and characteristics were established using a combination of focus groups, interviews, direct observation, task analysis and critique of current working environments. The challenge was to present the information to the design team in a useful manner. The format chosen was a modification of Userfit (Poulson 1996) that outlined the various characteristics of the patient group and the design consequences with “what does this mean for me” statements. During the block schematics phase an iterative design process was used to ensure that the ergonomic principles and the user needs were incorporated into the design. Ergonomic input was used in determining the room sizes and layout and to ensure work processes were considered. Simple mock-ups and anthropometric data assisted in illustrating the need for design changes. Examples that highlight the areas of greatest impact of ergonomic intervention include the patient bathrooms, showers and tub room. Significant changes were made to the design to improve the safety of the work and living space of the end users. One of the greatest challenges was having an appreciation for the individual goals of the team members. Ensuring there was adequate space for equipment and staff often resulted in recommendations for increased space. This in turn would increase the cost of the project. The architect and, later in the project, the engineer had goals of bringing the project in on budget. The final design was very much a team effort and truly die result of an iterative process. The sum of the individual contributions could not match the combined efforts. It was only through the ergonomic contributions in this early design phase that the needs of the staff, patients and families could be so well represented. The success of the iterative process provides the foundation for bringing ergonomics considerations into the early design stages of future projects.

Fatigue Life Improvement of Welded Elements and Structures by Ultrasonic Impact Treatment

2011 ◽  
Author(s):  
Yuriy Kudryavtsev ◽  
Jacob Kleiman
Keyword(s):  
Mechanical Properties ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Residual Stresses ◽  
Fatigue Testing ◽  
Highway Bridges ◽  
Surface Layers ◽  
Ultrasonic Impact Treatment ◽  
Stress Relieving ◽  
Life Improvement

The ultrasonic impact treatment (UIT) is relatively new and promising process for fatigue life improvement of welded elements and structures. In most industrial applications this process is known as ultrasonic peening (UP). The beneficial effect of UIT/UP is achieved mainly by relieving of harmful tensile residual stresses and introducing of compressive residual stresses into surface layers of a material, decreasing of stress concentration in weld toe zones and enhancement of mechanical properties of the surface layers of the material. The UP technique is based on the combined effect of high frequency impacts of special strikers and ultrasonic oscillations in treated material. Fatigue testing of welded specimens showed that UP is the most efficient improvement treatment as compared with traditional techniques such as grinding, TIG-dressing, heat treatment, hammer peening and application of LTT electrodes. The developed computerized complex for UP was successfully applied for increasing the fatigue life and corrosion resistance of welded elements, elimination of distortions caused by welding and other technological processes, residual stress relieving, increasing of the hardness of the surface of materials. The UP could be effectively applied for fatigue life improvement during manufacturing, rehabilitation and repair of welded elements and structures. The areas/industries where the UP process was applied successfully include: Shipbuilding, Railway and Highway Bridges, Construction Equipment, Mining, Automotive, Aerospace. The results of fatigue testing of welded elements in as-welded condition and after application of UP are considered in this paper. It is shown that UP is the most effective and economic technique for increasing of fatigue strength of welded elements in materials of different strength. These results also show a strong tendency of increasing of fatigue strength of welded elements after application of UP with the increase in mechanical properties of the material used.

Design for Product Variety: Key to Product Line Structuring

1995 ◽  
Author(s):  
Kosuke Ishii ◽  
Cheryl Juengel ◽  
C. Fritz Eubanks
Keyword(s):  
Supply Chain ◽  
Life Cycle ◽  
Manufacturing Process ◽  
Life Cycle Cost ◽  
Manufacturing System ◽  
Product Variety ◽  
Product Line ◽  
Customer Preference ◽  
The Cost ◽  
Structure Graph

Abstract This study develops a method to capture the broadest customer preference in a product line while minimizing the life-cycle cost of providing variety. The paper begins with an overview of product variety and its importance in overhead costs: supply chain, equipment and tooling, service, and recycling. After defining the product structure graph as a representation of variety, the paper introduces an approximate measure for the customer importance and life-cycle cost of product variety The cost measure utilizes the concept of late point identification which urges standardization early in the manufacturing process and differentiation at the end of the process. The variety importance-cost map allows engineers to identify cost drivers in the design of the product or the manufacturing system and seek improvements. The refrigerator door example illustrates the concept. On-going work seeks to validate and enhance the method with several companies from different industries.

Preliminary design of precast, segmental box-girder bridges using optimization

1979 ◽  
Vol 6 (1) ◽  
pp. 120-128
Author(s):  
Craig J. Miller ◽  
Juarez Accioly
Keyword(s):  
Minimum Cost ◽  
Preliminary Design ◽  
Box Girder Bridges ◽  
Cross Sectional ◽  
Box Girder ◽  
Prestressing Steel ◽  
Girder Bridges ◽  
Starting Point ◽  
Final Design ◽  
The Cost

Precast, prestressed segmental box-girder bridges are now accepted as an economical alternative for spans over 150 ft (46 m). Decisions about cross-sectional dimensions made during preliminary design can have a substantial influence on the final cost of the bridge. To help the designer obtain an economical starting point for a final design, a program was written to determine section dimensions and midspan and pier prestressing steel areas to give minimum cost. Since a preliminary design is obtained, the analysis techniques and design criteria have been simplified to reduce computation. The design produced by the program will satisfy AASHTO specification requirements and the recommendations of the PCI Bridge Committee. The optimization algorithm used is the generalized reduced gradient technique. To demonstrate the program capabilities, three example problems are discussed. The results indicate that optimum span-depth ratios are approximately 24 for the cost ratios used. The cost of the optimum design does not seem to be too sensitive to the ratio of concrete cost to prestressing steel cost.

Effect of Processing Layer on Fatigue Strength of Extruded AZ61 Magnesium Alloy

2013 ◽  
Vol 577-578 ◽  
pp. 429-432 ◽  
Author(s):  
Yukio Miyashita ◽  
Kyohei Kushihata ◽  
Toshifumi Kakiuchi ◽  
Mitsuhiro Kiyohara
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Magnesium Alloy ◽  
Crack Initiation ◽  
Crack Growth ◽  
Fatigue Crack Initiation ◽  
Fatigue Tests ◽  
Crack Growth Resistance ◽  
Az61 Magnesium Alloy

Fatigue Property of an Extruded AZ61 Magnesium Alloy with the Processing Layer Introduced by Machining was Investigated. Rotating Bending Fatigue Tests were Carried out with the Specimen with and without the Processing Layer. According to Results of the Fatigue Tests, Fatigue Life Significantly Increased by Introducing the Processing Layer to the Specimen Surface. Fatigue Crack Initiation and Propagation Behaviors were Observed by Replication Technique during the Fatigue Test. Fatigue Crack Initiation Life of the Specimen with the Processing Layer was Slightly Longer than that of the Specimen without the Processing Layer. Higher Fatigue Crack Growth Resistance was also Observed when the Fatigue Crack was Growing in the Processing Layer in the Specimen with the Processing Layer. the Longer Fatigue Life Observed in the Fatigue Test in the Specimen with the Processing Layer could be Mainly due to the Higher Crack Growth Resistance. it is Speculated that the Fatigue Strength can be Controlled by Change in Condition of Machining Process. it could be Effective way in Industry to Improved Fatigue Strength only by the Cutting Process without Additional Surface Treatment Process.

scholarly journals PENGARUH PENGHILANGAN KEKASARAN PERMUKAAN TERHADAP KEKUATAN FATIK = EFFECT OF SURFACE ROUGHNESS REMOVAL TO FATIGUE STRENGTH

2015 ◽  
Vol 9 (3) ◽  
pp. 115-130
Author(s):  
H. Agus Suhartono
Keyword(s):  
Surface Roughness ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Fatigue Loading ◽  
Bending Fatigue ◽  
Aisi 1045 Steel ◽  
Aisi 1045 ◽  
1045 Steel ◽  
Test Result ◽  
Effect Of Surface

The aim of the study is to investigate and to prove that the fatigue failure of steel is initiated from the surface. Hence the preventif action of smoothening the surface that has been loaded by fatigue loading is very important. The specimen of AISI 1045 Steel is loaded by means of rotary bending fatigue. The fatigue loading will be interupted as the fatigue life reaching 50% of fatigue life and 75% of fatigue life. During the interuption the specimen will be grinded and polished, before tested completely until fatigue fracture occured. The fatigue life of each group of scpecimen based on the art of loading will be compared to the specimen tested by fatigue loading without interuption.The Miner rule is used to evaluated the test result. The influence of interuption and surface treatment is evaluated and analyzed. ABSTRAKTujuan penelitian ini adalah untuk menyelidiki dan membuktikan bahwa kegagalan kelelahan baja dimulai dari permukaan. Oleh karena itu tindakan pencegahan dengan memperhalus permukaan sangat penting untuk mencegah beban kelelahan baja. Spesimen dari AISI 1045 Steel dimuat dengan cara uji kelelahan lentur putar. Kelelahan pemuatan akan disela sebagai umur kelelahan mencapai 50% dari umur kelelahan dan 75% dari umur kelelahan. Selama gangguan lainnya yang spesimen akan digiling dan dipoles, sebelum diuji benar-benar sampai patah akibat kelelahan yang terjadi. Umur kelelahan dari setiap kelompok specimen diuji berdasarkan beban akan dibandingkan dengan spesimen oleh kelelahan bongkar tanpa aturan. The Miner rule digunakan untuk mengevaluasi hasil tes. Pengaruh gangguan lainnya dan perlakuan permukaan dievaluasi dan dianalisis. 

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