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2022-08-20
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Research and application of injection mold CAE based on Web services

Abstract: This paper analyzes the architecture of Web services, introduces the characteristics and development process of the structure of injection mold CAE system, and puts forward the use of Web services architecture to solve the difficulties faced by the injection mold CAE system at this stage, and expounds the advantages of using web services architecture. The injection mold CAE prototype system based on Web services has been used in the teaching network system

Keywords: Web services; Injection mold; CAE; Flow simulation; UDDI; Simple object access protocol; WSDL

1 Introduction

the rapid development of computer networks in recent years has brought many new opportunities. Through the Internet, enterprises can conduct business exchanges directly, which reduces the transaction cost of enterprises and expands the scope of business partners. However, many new technical problems have been encountered in the development of computer networks. Because there has been no unified standard to regulate the cooperation behavior between enterprises, the interaction cost of heterogeneous application systems is still too high for many enterprises, and can only be applied to specific environments. Taking CAE system as an example, the integration of CAE system with CAD, cam, PDM and other systems appears. The emergence of Web services has solved this problem well

2 technological development from web applications to Web Services

2 1 basic concept of Web Services

conceptually, the structure of Web services is not a new technology, and its emergence is earlier than Java and the web. Sending requests to the server through tcp/ip, IIOP, RPCs or CGI to obtain related services can be called web services. HTTP protocol has been widely used. XML is very simple. It is a unified data language that allows data to be transferred between different systems and platforms. Web services use these Internet standards to realize the creation, discovery and invocation of resources in application systems. Transforming components in applications into web services, enterprises provide a standard method to define and publish these components, and other enterprises can find and request the services provided by these components

IBM defines web services as a new generation of web applications in the tutorial on Web services. They are self-contained, can describe the services they provide, can be published in the network, and can be located and invoked in the web. The functions provided by web services can be simple or contain very complex business logic. When web services are deployed, other applications can discover and request these services

structurally, web services are service-oriented. Here we need a service provider, a service consumer, and sometimes an agent of related services. Service providers publish service information that they can implement on the web, Respond to the services proposed by consumers "It has the potential to truly change the rules of the game in the composite industry. The service agent is an intermediary responsible for searching the services provided by service providers and classifying and registering these service information. In Web services, soap standard is responsible for defining how to request services, UDDI is responsible for publishing and discovering services, WSDL standard is responsible for self describing service information, and XML is the unified format of data information.

2 the characteristics of Web services

the structure of Web Services determines that web services have the following characteristics:

(1) universality

Web Services communicate with XML through HTTP. Therefore, any device that supports these two technologies can access Web services

(2) loosely coupled

Web services are loosely coupled with each other. Any party in the connection can change the execution mechanism without affecting the normal operation of the application

(3) ease of implementation

unlike existing distributed computing systems, web services have complex interfaces. Many manufacturers, including IBM and Microsoft, also provide a large number of free tools to quickly generate and deploy web services. At the same time, the existing JavaBean and COM component systems can easily turn to providing services in the form of Web services

(4) interoperability

any web service can interact with other web services

(5) wide support

almost all manufacturers support SOAP Protocol and related web service technologies

These characteristics of Web services make us find a near perfect solution to many problems that have appeared and may appear in the future in the research and development process of injection mold CAE

3 technical basis of Web services

3.1 XML text markup language

xml is a text markup language specification formulated by W3C. It is strictly defined structured data, which can be used to define and describe data. XML is a display independent data representation language, so XML also supports the automatic conversion of various devices and display environments. Developers do not need to prepare different content and data for devices of different sizes. The advantage of XML lies not only in the representation and description of data, but also in the definition of various exchangeable data structures in the form of text tags, which can be transmitted using standard network protocols. Because of these characteristics, XML actually represents the trend of platform neutrality and network computing. XML is the original driving force to promote the implementation of the whole web service architecture, and it is the technical basis for the implementation of Web services. Other protocol specifications that web services rely on are described and expressed based on XML. Therefore, it is XML that promotes the great changes of the whole network computing mode and business mode

3.2 soap (Simple Object Access Protocol)

soap (Simple Object Access Protocol) is an XML based protocol, which defines a standard way to transfer XML data and access remote objects/services independently of the platform. It includes the following three parts:

(1) an information package that describes the content of the message and how to process these contents, called an envelope

(2) a set of completed data coding rules, which define the serialization mechanism of application related data types

(3) a description of remote procedure calls and corresponding standards

3.3 UDDI (Universal discovery and Discovery Integration)

in September 2000, Arabi, Microsoft and IBM proposed a scheme: establish the standard of resource registration and discovery in Web services, which is the UDDI specification. In short, UDDI defines a white paper (directory of contact information) and a yellow page of Web services (classification information of providers providing these services). Today, many companies begin to support this specification and work together to improve it. In the first version of UDDI specification, the structure of accessing public services was defined. This specification mainly includes an XML plan, which defines the relevant protocols and API specifications of soap based registration and discovery services. According to the definition of: the purpose of UDDI is to establish a global, platform independent, open framework system, so that business system services can be found. It defines how to interoperate in the Internet and share information in the global unified registration information base

3.4 WSDL (Web Services Description Language)

WSDL is a standard formed after the combination of Microsoft SDL (servicesdescription language) and IBM nassl (network accessible services specification language) and acceptance by W3C. WSDL provides a standard method for service providers to describe the basic format of web service requests in XML format. WSDL is used to describe what a web service can do, where it is located, how to call it, etc. UDDI registration describes most aspects of Web services, including the details of service binding. WSDL can be regarded as a subset of UDDI service description

4 injection mold CAE system based on Web Service Architecture

injection mold CAE system is generally divided into the following three modules:

(1) pretreatment module, which is used to establish the geometric model of analytical products, define the gate, design the runner, select plastic materials and set process conditions

(2) the analysis module simulates reality according to certain algorithms according to the conditions set in the preprocessing, and performs flow analysis, pressure maintaining analysis, etc. The analysis module is the core of the whole injection mold CAE system, and it is also the most complex, time-consuming and resource consuming part

(3) post processing module, which displays the analysis results of flow analysis and pressure holding analysis, including the distribution of physical quantities such as the position of flow front, pressure field, temperature field, shear force field and shear rate field in the process of forming and pressure holding, and submits the result report and improvement suggestions

4.1 structure and characteristics of traditional injection mold CAE system

the traditional injection molding edge CAE system is shown in Figure 1

Figure 1 traditional injection mold CAE system

traditional injection mold CAE systems are mostly CAE systems based on workstations. It realizes the finite element analysis of the product model through three steps: pre-processing, finite element analysis and post-processing, which can quickly and conveniently help users determine the rationality of the design scheme and guide product design and development. Each part of this method is independent of each other, and the operation is simple and convenient, but there are also some shortcomings, such as large investment, poor data sharing, inconvenient system upgrading and information exchange, and does not support remote design and development

at the same time, the traditional CAE system of injection molding mold closely combines the three modules, which cannot realize distributed and open applications. The existing injection mold CAE system is generally developed with a specific language for a specific operating system. Even if each module is made into a loosely coupled component form, there are still a series of problems such as cross platform and cross development language

4.2 development direction of injection mold CAE system

with the development of computer network, network-based virtual manufacturing technology is developing rapidly, and an application scheme of injection mold CAE system based on internet/intranet appears, as shown in Figure 2. Its overall idea is to make full use of the advantage of network bandwidth and separate the user interface from background analysis. The user interface provides parameter design, product entity information entry, result display, etc; The modules responsible for pre-processing, post-processing and finite element analysis are placed on the server, and the analysis data are uniformly managed by the server. In this way, a CAE system composed of an integrated finite element analysis system based on network and an open user interface on the client side is formed

Figure 2 injection mold CAE system based on Internet/Intranet

this idea of placing the analysis module on the server independently is a great progress. It has such characteristics: it makes users no longer need to configure a high-performance computer for each set of injection mold CAE system when using the injection mold CAE system. Because the time-consuming and resource consuming finite element analysis module is placed on a special server for calculation, if necessary, several server clusters can even be used for distributed analysis and calculation to improve the analysis speed; At the same time, the data is managed uniformly on the server side, which is convenient to realize the rich technical accumulation of data sharing and automation; Moreover, this mechanism is suitable for remote development. Enterprises place the CAE system server in a certain location, and any remote user can conduct real-time remote analysis and view the results as long as he can access it and has permission

4.3 problems in the development of injection mold CAE system

from the development of injection mold CAE system to the present, there have been some problems, such as high degree of tight coupling of system structure, low reusability, substandard specification, and limited by specific language or specific operating system, which make one or another problems appear when integrating with CAD, cam, PDM and other systems. Even if the integration is barely achieved

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