Dong Yan Shi

Enhancing the Ideality of Innovation by AD/TOC/TRIZ

In order to enhance ideality of innovation by comprehensive application of all aspects which affect ideality, we propose a framework which embeds the theory of constraints and TRIZ into the customer domain, function domain and physical domain of axiomatic design. The dataflow is described from customer domian to physical domain through function domain in this framework, and a case study is used to shown the validation.

Study on Shell-Solid Coupling Method of Trunk Structure for Efficient FE Analysis

The FE modeling of complex trunk structure often needs shell and solid elements. Different commercial software adopts different shell-solid coupling techniques. A simple, robust method has been demonstrated for shell–solid coupling by fictitious perpendicular shell. Systemic study on the method is performed through the FE analysis of T-trunk model to ensure the displacement compatibility and stress equilibrium. Modal analysis of gearbox is executed to observe the reliability and efficiency of the coupling method. Parametrical conclusions and practical suggestions are presented finally.

Fuzzy Design Scheme Selection Method Based on QFD Integrated with TRIZ

A new framework of decision-making is proposed in this paper to accommodate the application of quality function deployment (QFD) integrated with TRIZ. In the proposal framework, Ideal Final Result (IFR) oriented decision-making process is introduced for the innovation design process in order to select the best solution from alternatives which are generated by TRIZ and consistent with the laws of technical system evolution. Overall customer satisfaction oriented decision-making process is applied for the alternatives generated from both innovation design process and adaptive design process. The correlation matrix, which affects the weight of criteria, is modified according to the style of broken contradiction for the application of TRIZ. Meanwhile, triangular fuzzy numbers are utilized to deal with vagueness of human thought. Finally, an example is taken to show application of the framework.

Determination of the Optimum Material for an Endodontic Prefabricated Post Using a Sub-Problem Approximation Method

The success in the chewing process depends on the performance of the tooth used. Actually, taking care of the tooth and improving its performance can change our life. Therefore, the treatment process of the teeth has become more necessary in the life of a dental patient. Nowadays, a post plays an important vital role in this process. In the present work, analysis of the effect of the post material on the performances of the components of endodontically treated teeth (ETT) was carried out through the finite element analysis (FEA). The effects of post material on the von Mises stress component (Svon), shear stress, and displacement component (Usum) occurred on the all components of ETT were investigated. After that, the determination of the optimum material for an endodontic prefabricated post (EPP) was investigated through the sub-problem approximation method.

Determining the Optimum Material for an Endodontic Prefabricated Parallel Post Using a Sub-Problem Approximation Method

One of the most widely used techniques in present-day in order to save teeth is endodontic treatment (ET). Nowadays, a post or a dowel is widely used in the tooth treatment process. The aims of the current investigation are to: (1) evaluate the stress distribution surrounding the endodontic prefabricated parallel post (EPPP), gutta-percha, and dentin with six types of post materials, and (2) determine the optimum material of an EPPP. Six post materials: (1) carbon fibre post (CFP), (2) gold (G), (3) gold alloy (GA), (4) titanium (T), (5) titanium alloy (TA), and (6) stainless steel (SS) were selected in the present work. In order to evaluate the stress distribution surrounding the EPPP, gutta-percha, and dentin with different post materials, the finite element analysis (FEA) is adopted. After that, the sub-problem approximation method was used in order to investigate the optimum material of an EPPP. The results obtained indicate that the optimum elastic characteristics for the EPPP, elastic modulus (E), and Poisson’s ratio (υ) equal to 185 GPa and 0.245, respectively.

Optimum Gradation Direction for a Functionally Graded Endodontic Prefabricated Parallel Post: A Finite Element Method

The main purpose of the present work is to determine the optimum gradation direction of an endodontic prefabricated parallel post (EPPP) made of functionally graded material (FGM). To determine the optimum gradation direction of an EPPP made of FGM, the finite element method (FEM) is used. After that, the optimization technique was adopted in order to determine the optimum material gradient for the functionally graded endodontic prefabricated parallel post (FGEPPP). Simulation results indicated that, the optimum gradation direction for the FGEPPP is from up to down, and can be described by using a modified sigmoid function. The effect of varying of the material gradient indexes on the performance of the (FGEPPP) is investigated. Also, stress distributions in all of FGEPPP cases and in homogeneous EPPP case are investigated. The current investigation shows that, the use of the FGM improves the performance of an EPPP.

Stress Distribution Surrounding Endodontic Prefabricated Parallel Post

The identification of the optimum material of an endodontic prefabricated parallel post (EPPP) is carried out in the current study. The primary goal of the current work is to analyze the effect of post material on the stress distribution surrounding EPPP. Ten different post materials: 1-carbon fibre (CF), 2-gold alloy (GA), 3-titanium alloy (TA), 4-stainless steel (SS), 5-composite resin (CR), 6-fiber reinforced composite (FRFC), 7-carbon (C), 8-glass fiber (GF), 9-zirconia (Z), and 10-ribbond fiber+bonding agent+flowable composite (RBF) are used in the present work. In order to identify the best post material, the stress distribution surrounding EPPP with the previous materials are investigated through finite element analysis (FEA). The results obtained show that, the best material of an EPPP is GF. In this study, in order to identify the optimum material of an EPPP, the optimization technique is adopted. The results obtained show that, the optimum values of elastic modulus (E) and Poisson’s ratio (υ) equal to 63.69 GPa and 0.214115, respectively. These resulting values mean that, the optimum material of an EPPP is borosillicate glass (BG).

FE Analysis of the Effect of Material Gradient on the Performance of a Functionally Graded Endodontic Prefabricated Parallel Post

A study of the effect of material gradient on the performance of a functionally graded endodontic prefabricated parallel post (FGEPPP) is the main goal of the current study. Elastic modulus (E) of FGEPPP is considered to vary continuously from lower to upper surfaces. This variation is performed according the volume fraction. Based on a modified sigmoid function, the volume fraction will be defined in the present work. The primary goal of the current investigation is to analyze the difference between the performance of a homogeneous endodontic prefabricated parallel post (EPPP) and a FGEPPP through finite element analysis (FEA). In the current investigation, von Mises stress, and shear stress in FGEPPP case with a modified sigmoid function and in homogeneous EPPP case are carried out. After that, the effect of material gradient on the performance of an EPPP made of FGM was carried out through FEA in the current investigation. The simulation cases shown that, the maximum values of von Mises stress, and shear stress increase when increasing the value of “D”, and decrease when increasing the value of “w”.

FE Analysis of Functionally Graded Material Plate during Debonding Case with Different Boundary Conditions

Functionally graded materials (FGMs) have become helpful in our engineering applications. Analysis of functionally graded material (FGM) plate during debonding case with different boundary conditions is the main purpose of this investigation. Elastic modulus (E) of functionally graded (FG) plate is assumed to vary continuously throughout the height of the plate, according the volume fraction of the constituent materials based on a modified sigmoid function, but the value of Poisson coefficient is constant. In this research, the finite element method (FEM) is used in order to show the shape of a plate made of FGM during debonding case with different boundary conditions. In the present investigation, the displacement value applied to the FGM plate is changed in order to find the relationship between the maximum von Mises stress and the displacement. Also, the relationship between the maximum shear stress and the displacement is carried out in the present work. The material gradient indexes of the FGM plate are changed from 1 to 10. The stress distributions around the debonding zone with all the material gradient indexes of the FGM plate are investigated in this work.

Research on Evolutionary Topology Optimization in ANSYS

Topology optimization function in ANSYS software is inefficient with the limitation of element types. By using the secondary developing language APDL and UIDL, the secondary development of bi-directional evolutionary structural optimization (BESO) method with volume constraint and stiffness maximization is completed in ANSYS. To suppress the checkerboard patterns, the elemental sensitivity numbers are recalculated by a filter method. To ensure the convergence of the optimization method in ANSYS, the elemental sensitivity numbers are updated by adding in their historical information. Two classic numerical examples are calculated to obtain the best topology structure. The numerical results indicate that the secondary method can solve the 2D and 3D problems effectively, which makes up for the deficiency of topology optimization part in ANSYS and broadens the application scope of the evolutionary optimization method.