A Geometric Model for Tolerance Analysis with Manufacturing Signature and Operating Conditions

2019 ◽  
Vol 9 (3) ◽  
pp. 1-13
Author(s):  
Wilma Polini ◽  
Andrea Corrado
Keyword(s):  
Concurrent Engineering ◽  
Manufacturing Process ◽  
Geometric Model ◽  
Tolerance Analysis ◽  
Operating Conditions ◽  
Geometric Reasoning ◽  
Assembly Sequence ◽  
Turning Process ◽  
Engineering Approach

In this work, a geometric model for tolerance analysis has been carried out. Geometric reasoning has been implemented in the model to simulate the manufacturing process and, then, the assembly sequence. The proposed geometric model has been applied to a case study consisting of two circular profiles due to the turning process, and a hollow rectangular box. The two circular profiles have been assembled inside the box by considering the gravity, and the friction among the parts and the actual points of contact with and without using the manufacturing signature. Matlab® software has been used to implement the geometric model for tolerance analysis. The results have been compared with those obtained by using a literature model with and without considering the manufacturing signature. This work aims to be a first step towards the integration of the design and the manufacturing in a concurrent engineering approach.

Process Signature Modeling for Tolerance Analysis

2010 ◽  
Vol 10 (2) ◽  
Author(s):  
R. Ascione ◽  
W. Polini ◽  
Q. Semeraro
Keyword(s):  
Concurrent Engineering ◽  
Manufacturing Process ◽  
Tolerance Analysis ◽  
Actual Surface ◽  
Contact Points ◽  
Geometric Tolerances ◽  
Systematic Pattern ◽  
Process Signature ◽  
Nominal Surface

Many well-known approaches exist in the literature for tolerance analysis. All the methods proposed in the literature consider the dimensional and the geometric tolerances applied to some critical points (contact points among profiles belonging to couples of parts) on the surface of the assembly components. These points are generally considered uncorrelated since the nominal surface is considered. Therefore, the methods proposed in the literature do not consider the actual surface due to a manufacturing process. Every manufacturing process leaves on the surface a signature, i.e., a systematic pattern that characterizes all the features machined with that process. The aim of the present work is to investigate the effects of considering the manufacturing signature in solving a tolerance stack-up function. A case study involving three parts has been defined and solved by means of a method of the literature, the variational method, with and without considering the correlation among the points of the same surface due to the manufacturing signature. This work represents a first step toward the integration of the design and the manufacturing in a concurrent engineering approach.

Enhancement of Turning Process Using Vibration Signature Analysis

2005 ◽  
Author(s):  
Marlon C. Batey ◽  
Hamid R. Hamidzadeh
Keyword(s):  
Manufacturing Process ◽  
Vibration Analysis ◽  
Manufacturing System ◽  
Cutting Tool ◽  
Operating Conditions ◽  
Turning Process ◽  
Analysis Problem ◽  
Frequency Domains ◽  
Vibration Signature ◽  
Vibration Signatures

Analytical and experimental vibration analyses are conducted for a lathe system to detect the possibility of faults and develop an accurate cutting process. The data acquisition system utilized for this purpose processes the analog input from the manufacturing system and displays the response in both the real time and frequency domains. The vibration signatures for different arrangements are recorded to determine the dynamic characteristics of the system which includes work pieces, tool, and lathe components. These vibration signatures were analyzed to determine cause of inaccuracy in the manufacturing process and the faulty components. In this study, two major problem causing sources were identified using vibration analysis for the system under different operating conditions. In addition to the identified problems, the phenomena of cutting tool chatter with various intensities was examined and recorded during testing. In this study the best possible operating conditions for a specific turning process were determined using vibration analysis. Problem causing components for several case studies (different speeds, feed rates, and tool lengths) were identified and guidelines for improving a typical manufacturing process were recommended.

A Method for Integrating Form Errors Into Geometric Tolerance Analysis

2005 ◽  
Author(s):  
Robert Scott Pierce ◽  
David Rosen
Keyword(s):  
Manufacturing Process ◽  
High Speed ◽  
Tolerance Analysis ◽  
Analysis Model ◽  
Geometric Tolerance ◽  
Form Errors ◽  
Product Function ◽  
Component Models ◽  
Insight Into

In this research we describe a computer-aided approach to geometric tolerance analysis for assemblies and mechanisms. This new tolerance analysis method is based on the “generate-and-test” approach. A series of as-manufactured component models are generated within a NURBS-based solid modeling environment. These models reflect errors in component geometry that are characteristic of the manufacturing processes used to produce the components. The effects of different manufacturing process errors on product function is tested by simulating the assembly of these imperfect-form component models and measuring geometric attributes of the assembly that correspond to product functionality. A tolerance analysis model is constructed by generating-and-testing a sequence of component variants that represent a range of manufacturing process capabilities. The generate-and-test approach to tolerance analysis is demonstrated using a case study that is based on a high-speed stapling mechanism. As-manufactured models that correspond to two different levels of manufacturing precision are generated and assembly between groups of components with different precision levels is simulated. Misalignment angles that correspond to functionality of the stapling mechanism are measured at the end of each simulation. The results of these simulations are used to build a tolerance analysis model and to select a set of geometric form and orientation tolerances for the mechanism components. It is found that this generate-and-test approach yields insight into the interactions between individual surface tolerances that would not be gained using more traditional tolerance analysis methods.

Manufacturing Signature for Tolerance Analysis

2015 ◽  
Vol 15 (2) ◽  
Author(s):  
Polini Wilma ◽  
Moroni Giovanni
Keyword(s):  
Sensitivity Analysis ◽  
Manufacturing Process ◽  
Tolerance Analysis ◽  
Variational Model ◽  
Form Tolerance ◽  
Systematic Pattern

Every manufacturing process leaves on the surface a signature, i.e., a systematic pattern that characterizes all the features machined with that process. The present work investigates the effects of considering the manufacturing signature in solving a tolerance stack-up function. A new variational model was developed that allows to deal with the form tolerance. It was used to solve a case study involving three parts with or without considering the correlation among the points of the same surface due to the manufacturing signature. A sensitivity analysis was developed by considering different values of the applied geometrical tolerances.

scholarly journals An Optimization Workflow in Design for Additive Manufacturing

2021 ◽  
Vol 11 (6) ◽  
pp. 2572
Author(s):  
Stefano Rosso ◽  
Federico Uriati ◽  
Luca Grigolato ◽  
Roberto Meneghello ◽  
Gianmaria Concheri ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Structural Optimization ◽  
Geometric Model ◽  
Complex Geometries ◽  
Design Phase ◽  
Design For Additive Manufacturing ◽  
Engineering Software ◽  
Embodiment Design ◽  
Pros And Cons

Additive Manufacturing (AM) brought a revolution in parts design and production. It enables the possibility to obtain objects with complex geometries and to exploit structural optimization algorithms. Nevertheless, AM is far from being a mature technology and advances are still needed from different perspectives. Among these, the literature highlights the need of improving the frameworks that describe the design process and taking full advantage of the possibilities offered by AM. This work aims to propose a workflow for AM guiding the designer during the embodiment design phase, from the engineering requirements to the production of the final part. The main aspects are the optimization of the dimensions and the topology of the parts, to take into consideration functional and manufacturing requirements, and to validate the geometric model by computer-aided engineering software. Moreover, a case study dealing with the redesign of a piston rod is presented, in which the proposed workflow is adopted. Results show the effectiveness of the workflow when applied to cases in which structural optimization could bring an advantage in the design of a part and the pros and cons of the choices made during the design phases were highlighted.

scholarly journals Waste reduction of polypropylene bag manufacturing process using Six Sigma DMAIC approach: A case study

2021 ◽  
Vol 8 (1) ◽  
pp. 1896419
Author(s):  
Muhammad Hamad Sajjad ◽  
Khawar Naeem ◽  
Muhammad Zubair ◽  
Qazi Muhammad Usman Jan ◽  
Sikandar Bilal Khattak ◽  
...  
Keyword(s):  
Six Sigma ◽  
Manufacturing Process ◽  
Waste Reduction

Concurrent Engineering Assessment: A Proposed Framework

1996 ◽  
Vol 210 (4) ◽  
pp. 321-328 ◽  
Author(s):  
J Poolton ◽  
I Barclay
Keyword(s):  
Product Development ◽  
New Product Development ◽  
Concurrent Engineering ◽  
Research Study ◽  
New Product ◽  
Using Data ◽  
Past Experiences ◽  
Depth Interviews

There are few studies that have found an adequate means of assessing firms based on their specific needs for a concurrent engineering (CE) approach. Managers interested in introducing CE have little choice but to rely on their past experiences of introducing change. Using data gleaned from a nine month case study, a British-wide survey and a series of in-depth interviews, this paper summarizes the findings of a research study that examines how firms orientate themselves towards change and how they go about introducing CE to their operations. The data show that there are many benefits to introducing CE and that firms differ with respect to their needs for the CE approach. A tentative means to assess CE ‘needs’ is proposed which is based on the level of complexity of goods produced by firms. The method is currently being developed and extended to provide an applications-based framework to assist firms to improve their new product development performance.

EVOLUTIONARY APPROACH IN PROCESS IMPROVEMENT — A CASE STUDY IN AUTO ELECTRICAL ALTERNATOR MANUFACTURING

2012 ◽  
Vol 11 (01) ◽  
pp. 27-50 ◽  
Author(s):  
A. J. JEGADHEESON ◽  
L. KARUNAMOORTHY ◽  
N. ARUNKUMAR ◽  
A. BALAJI ◽  
M. RAJKAMAL
Keyword(s):  
Process Improvement ◽  
Manufacturing Process ◽  
Welding Process ◽  
Evolutionary Approach ◽  
Geometrical Analysis ◽  
Designed Experiments ◽  
Self Development ◽  
Riveting Process

Evolution is "understanding and overcoming current constraints in small steps toward optimum." "Understanding" requires elucidation of facts and corroborating theories that can explain those facts in a coherent manner. "Overcoming" requires self-development to suit the environment. In this paper, a case study about how a manufacturing process is improved in terms of productivity and quality using evolutionary improvements is explained. Here "Understanding" is achieved through use of Shainin Technique, PM analysis, Affinity Diagram, and the engineer's ingenuity, along with Relations diagram. "Overcoming" is achieved through Geometrical Analysis and Designed Experiments. The Study has set a new benchmark in the Stator riveting process by proving it can yield the desired results, and the need to adapt welding process is avoided.

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