Conceptual Design Method for Reducing Brake Squeal in Disk Brake Systems Considering Unpredictable Usage Factors

2012 ◽  
Vol 134 (6) ◽  
Author(s):  
Toru Matsushima ◽  
Kazuhiro Izui ◽  
Shinji Nishiwaki

Minimizing brake squeal is one of the most important issues in the development of high performance braking systems. Furthermore, brake squeal occurs due to the changes in unpredictable factors such as the friction coefficient, contact stiffness, and pressure distribution along the contact surfaces of the brake disk and brake pads. This paper proposes a conceptual design method for disk brake systems that specifically aims to reduce the occurrence of low frequency brake squeal at frequencies below 5 kHz by appropriately modifying the shapes of brake system components to obtain designs that are robust against changes in the above unpredictable factors. A design example is provided and the validity of the obtained optimal solutions is then verified through real-world experiments. The proposed optimization method can provide useful design information at the conceptual design stage during the development of robust disk brake systems that maximize the performance while minimizing the occurrence of brake squeal despite the presence of unpredictable usage factors.

2011 ◽  
Vol 328-330 ◽  
pp. 232-236
Author(s):  
Lian Zhong Guo ◽  
Ding Yang ◽  
Zi Teng Huang

The purpose of this work is to present an optimal design method for radar brackets to get the lightest structure with stiffness constraint. Current radar brackets usually have conservative strength and excessive weight which influences the mobility of radar greatly as they are not optimized in the conceptual design stage. In this paper the well-known ESO (Evolutionary Structural Optimization) method based on ANSYS is studied and used as the method to optimize them. To begin with the criteria of ESO method and its implementation method are studied. Then a case of optimization for a phased array radar bracket is studied and at last the optimization result is compared to the result by using WORKBENCH (a commercial CAE software) and the comparison shows that this method has its unique superiority.


2015 ◽  
Vol 761 ◽  
pp. 63-67 ◽  
Author(s):  
Muhd Ridzuan Mansor ◽  
S.M. Sapuan ◽  
A. Hambali ◽  
Edi Syam Zainudin ◽  
A.A. Nuraini

Spoilers are part of an automotive exterior bodywork system that acts to create additional down force for higher traction. In this paper, a new conceptual design of automotive spoiler component using kenaf polymer composites was developed using integrated TRIZ and morphology chart design method. The aim is to enable direct application of kenaf polymer composites to the spoiler design to achieve better environmental performance of the component while maintaining the required structural strength for safe and functional operation. The overall process involved two major stages, which are the idea generation and concept development. TRIZ method was applied in the idea generation stage where specific solution strategies for the design were created. In the concept development stage, the specific TRIZ solution strategies obtained were later refined into relevant alternative system elements using Morphology chart method. Finally, a new conceptual design of an automotive spoiler was developed using the combination of the identified system elements. The integrated TRIZ and morphology chart method were found to be new tools that can be used effectively in the concept design stage, especially in cases where direct material substitution is given the main focus for the new product development.


Author(s):  
Toru Matsushima ◽  
Shinji Nishiwaki ◽  
Shintarou Yamasaki ◽  
Kazuhiro Izui ◽  
Masataka Yoshimura

Minimizing brake squeal is one of the most important issues in the development of high performance braking systems. Recent advances in numerical analysis, such as finite element analysis, have enabled sophisticated analysis of brake squeal phenomena, but current design methods based on such numerical analyses still fall short in terms of providing concrete performance measures for minimizing brake squeal in high performance design drafts at the conceptual design phase. This paper proposes an optimal design method for disc brake systems that specifically aims to reduce brake squeal by appropriately modifying the shapes of the brake system components. First, the relationships between the occurrence of brake squeal and the geometry and characteristics of various components is clarified, using a simplified analysis model. Next, a new design performance measure is proposed for evaluating brake squeal performance and an optimization problem is then formulated using this performance measure as an objective function. The optimization problem is solved using Genetic Algorithms. Finally, a design example is presented to examine the features of the optimal solutions and confirm that the proposed method can yield useful design information for the development of high performance braking systems that minimize brake squeal.


Author(s):  
Hyunwoong Ko ◽  
Seung Ki Moon

Additive Manufacturing (AM)’s advance from rapid prototyping to the end-of-use products inevitably challenges conventional design theories and methodologies. Especially while adopting systematic engineering design methodologies to design for AM (DfAM), it is essential to develop new design methods that explore the new design space enabled by AM’s design freedom from the early design stage. To address the challenge, this study provides a new design framework and a design method for modeling AM-enabled product behaviors in the conceptual design phase of DfAM. Firstly, this study contrasts function-based methods with affordance-based methods. The device-centric, form independent and input/output-based transformative properties of the function-based methods such as function decompositions have strengths in modeling product’s internal behaviors. However, the function-based methods show limitations in the new area of AM-enabled mass personalization which requires design approaches for representing user-centric structural design requirements acquired only by AM’s design freedom. On the other hand, the affordance-based methods can address the function-based methods in DfAM due to their user-centric (artifact-user interactive), form dependent and non-transformative properties. After the contradiction, we propose an affordance-based DfAM framework and an affordance structure as a formal modeling technique for AM-enabled personalized product behaviors. A case study of a trans-tibial prosthesis socket provides an illustration in this study. The contribution of the study is in developing a design method for the conceptual design phase of DfAM that fulfills the objectives of achieving AM-enabled mass personalization with systematic engineering design approaches.


Author(s):  
Katsuya Mogami ◽  
Kazuhiro Izui ◽  
Shinji Nishiwaki ◽  
Masataka Yoshimura ◽  
Nozomu Kogiso

Since decision-making at the conceptual design stage critically affects final design solutions at the detailed design stage, conceptual design support techniques are practically mandatory if the most efficient realization of optimal designs is desired. Topology optimization methods using discrete elements such as frame elements enable a useful understanding of the underlying mechanics principles of products, however the possibility of changing prior assumptions concerning utilization environments exists since the detailed design process starts after the completion of conceptual design decision-making. In order to avoid product performance reductions due to such later-stage environmental changes, this paper discusses a reliability-based topology optimization method that can secure specified design goals even in the face of environmental factor uncertainty. This method can optimize mechanical structures with respect to two principal characteristics, namely structural stiffness and eigen-frequency. Several examples are provided to illustrate the utility of the method presented here for mechanical design engineers.


Author(s):  
Michael E. Stock ◽  
Robert B. Stone ◽  
Irem Y. Tumer

In today’s world it is more important than ever to quickly and accurately satisfy customer needs when launching a new product. It is equally important to design products that adequately accomplish their desired functions with a minimum amount of failures. When failure analysis and prevention are coupled with a product design from its conception, shorter design times and fewer redesigns are necessary to arrive at a final product design. In this article, we explore the potential of a novel design methodology to guide designers toward new designs or redesigns that avoid failures. The Elemental Function-Failure Design Method (EFDM) is based on functional similarity of the product being designed to failed products within a knowledge base. The idea of using component functionality to explore the failure space in design was first introduced as a function-failure analysis approach by Tumer and Stone (2003). The overall approach offers potential improvement over current failure analysis methods (FMEA, etc.), because it can be implemented hand in hand with other conceptual design steps and carried throughout a product’s design cycle. In this paper, this idea is formalized into a systematic methodology that is specifically tailored for use at the conceptual design stage before any physical design choices have been made, hence moving failure analysis earlier in the design cycle. In the following, formalized guidelines for using the EFDM will be outlined for use in new designs and for redesign in existing products. A function-failure knowledge base, derived from actual failure occurrences for Bell 206 rotorcraft will be introduced and used to derive potential failure modes in a comparison of the EFDM and traditional FMEA for two design examples. This comparison will demonstrate the EFDM’s potential in conceptual design failure analysis.


2010 ◽  
Vol 76 (8) ◽  
pp. 973-980 ◽  
Author(s):  
Toru MATSUSHIMA ◽  
Kazuhiro IZUI ◽  
Shinji NISHIWAKI

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