Jun Peng Stanford University – Department of Civil and Environmental Engineering Nov 17, 2000 DISSERTATION PROPOSAL A Software Framework for Collaborative Development of Structural Analysis Code

Outline  Motivations and Objectives (Why)  Introduction: System Overview (What)  On-line Element Services (How 1) Distributed Element Service Dynamic Shared Library Element Service  On-line Data Access System (How 2)  Summary: Next Step

Workstations, Parallel Computers, Distributed Networked Workstations Element library CORE DEVELOPMENT MODEL (OpenSees) Library classes: ModelBuilder Domain classes Solver library Nonlinear strategies etc... Users Network (Internet or Others) Solution Strategies: Linear Algebra Operations -- linear direct/iterative solvers, eigensolvers, nonlinear solvers, etc.. Analysis Strategies Staggered Scheme, Local- Global Analysis Scheme, Simplified Analysis and Modeling, etc.. migration to core for collaborative use Check-in/Check-out Object Wrapper/ Interface (W/I) Element W/I Element W/I development stage migration to core for collaborative use Database For output and post-processing Collaborative Finite Element Program Environment

Motivation and Objective  Develop a software framework that would allow engineers and users to easily access the analysis platform.  Provide a plug-and-play environment where researchers and developers can build incrementally on each other’s successes.  Bring the state-of-the-art computing methodologies into the state-of-practice in structural engineering analysis. New Developments OpenSees CORE Internet Database Distributed Models

Outline  Motivations and Objectives (Why)  Introduction: System Overview (What)

Collaborative System Architecture OpenSees

Analysis Core Server Modules

ON-LINE ELEMENT SERVICE REGISTRY Query 4 THE ANALYSIS CORE THE ANALYSIS CORE Perform Analysis 3 SERVER INTERFACE Submit Analysis Model 2 Register to Core 1 7 Collaborative Computation 65 WEB-BASED CLIENT Results 8 Mechanics of the Collaborative Framework

File Submission for Analysis ModelAnalysis Results Internet Example of a Sample Client

Outline  Motivations and Objectives (Why)  Introduction: System Overview (What)  On-line Element Services (How 1) Distributed Element Service Dynamic Shared Library Element Service

There are Two types of on-line Element Services: 1. Distributed services (RPC, Java RMI or CORBA) 2. Download dynamic shared library (FTP or HTTP) Registration and Naming Service

Distributed Element Service

Distributed Element Service: Interaction Diagram QuadBuilder (C++) QuadElement Server (java) QuadElement (java) Stiff (C, Fortran) QuadElement Client (java) QuadElement (C++) G3 (C++) Classes buildFE_Model() QuadElement() formElement() new() calculateStiff() getStiff() return getStiff() OpenSees Core Element Service

Dynamic Shared Library Element Service

Advantages:  Flexibility: Dynamic execution at run-time; the server is able to run different services with the same interface.  Extendibility: Easily extended to incorporate new modules (even after installation); enhance software maintenance and upgrade.  Ownership: library source code controlled by its developer; facilitate bug-fixing and version control. Disadvantages:  Platform Dependency: Not all operating systems support dynamic loading and binding.  Security: Intrusion (virus, etc..) due to dynamic binding of “foreign” code from other site.  Overhead: Minor overhead cost due to file download and dynamic binding. Dynamic Shared Library: Pros and Cons

Outline  Motivations and Objectives (Why)  Introduction: System Overview (What)  On-line Element Services (How 1) Distributed Element Service Dynamic Shared Library Element Service  On-line Data Access System (How 2)

BrowserWebServer Database AppServer Java Servlet OpenSees Dynamic HTML With JavaScript Pages ORACLE 8i Apache With Tomcat Stored Procedure ODBC Web Client Presentation Server Application Server Data Server On-line Data Access  OpenSees can be turned into Application Server that resides in the middle layer for handling communication between Web Server and Database as well as incorporating Analysis logic and functionalities.

Web Server Database ODBC Engine OpenSees CORE On-line Data Access

Outline  Motivations and Objectives (Why)  Introduction: System Overview (What)  On-line Element Services (How 1) Distributed Element Service Dynamic Shared Library Element Service  On-line Data Access System (How 2)  Summary: Next Step

 The framework provides a means of distributing services in a modular and systematic way. Users can select appropriate services and can easily replace a service if superior service becomes available.  It provides a easy way to integrate legacy code as one of the modular services in the infrastructure.  It alleviates the burden of managing a group of developers and their source code. The participants can write their code based on the common communication protocol. Benefits of Distributed Service

Data Access System:  Finalize the data access system design  Improve performance of data query  Provide web-based user interface for data query Distributed System:  Standardize element interface  Further implement registration and naming service  Improve distributed element services Next Step Idea / PlanPrototypeProduct try Implementation Component Based Modeling:  Identify a component reference model  Model components and frameworks with UML

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