2. INTRODUCTION
• Virtual Manufacturing is defined as a computer
system which is capable of generating information
about the structure, states, and behavior of a
manufacturing system as can be observed in a real
manufacturing environment. In other words, a VM
system produce no output such as materials and
physical products , but it can produce information
about them VM is an integrated computer-based
model which represents the physical and logical
schema and the behavior of a real manufacturing
system.
WHAT IS VIRTUAL
MANUFACTURING?
3. • VM can be used in the evaluation of the feasibility of a product design,
validation of a production plan, and optimization of the product design
and processes. These reduce the cost in product life cycle.
• VM can be used to test and validate the accuracy of the product and
process designs. For example, the outlook of a product design, dynamic
characteristics analysis, checking for the tool path during machining
process, NC program validation, checking for the collision problems in
machining and assembly etc.
• With the use of VM on the internet, it is possible to conduct training
under a distributed virtual environment for the operations, technicians
and management people on the use of manufacturing facilities. The
costs of training and production can thus be reduced.
• As a knowledge acquisition vehicle, VM can be used to acquire
continuously the manufacturing know-how, traditional manufacturing
process, production data etc. This can help to upgrade the level of
intelligence of a manufacturing system.
WHY IS VIRTUAL
MANUFACTURING
NEEDED?
4. • QUALITY
• SHORTER CYCLE TIME
• PRODUCIBILITY
• FLEXIBILITY
• RESPONSIVENESS
• CUSTOMER RELATIONS
WHAT ARE THE
BENEFITS THAT WE
WILL GET OUT OF
USING VIRTUAL
MANUFACTURING?
5.
6. A CASE STUDY
VIRTUAL MANUFACTURING SIGNIFICANTLY REDUCED FUEL COSTS FOR
BOEING
Problem
During the metal-forming process of aircraft skin panels, the work piece undergoes
large deformations and accumulates considerable plastic strain. Upon release of the
work piece, the part recovers the elastic energy stored in it. This causes the deformed
part to deviate from the desired shape. Historically, empirical methods were used to
determine this spring-back effect after forming the panel. In the modern era, such
methods are impractical and cost prohibitive, especially because of the large number of
various parts in a modern airplane. A new stretch form block shape must be designed
with the inherent Spring back accounted for. Without optimized die shapes, the quality
of the part suffers, leading to assembly problems that are compensated for by trimming
and shims to attain a proper fit. Such difficulties can extend production schedules
unpredictably. The final installed aircraft skins can become wavy, resulting in reduced
fuel economy over the life of the aircraft.
7. SOLUTION ACHIEVED BY USING VM
By using the nonlinear finite element (FEA) software, MSC. Marc, to simulate the metal-forming process, the spring-back can
be accurately predicted before the real die is built. The material often used is aluminum, which is elastic-plastic with large
deformation in the plastic region. There is material, geometric, and boundary nonlinearity involved. The software must be
able to accurately predict this spring back effect. To optimize the die shape, a trial-and-error procedure is required. Instead of
implementing the trial-and error procedure on the real model, FEA is used to find the optimal die shape. Using MSC. Marc's
automated contact applied to 3-D bodies required no exotic programming by the end user to converge on a solution, making
it a very practical tool for this virtual manufacturing simulation. Once a Stretch Form Block shape was designed, a robotics
model of the stretch press was undertaken to determine the optimal control of the sheet-forming process. Once the robotics
model was optimized in the virtual environment, the data was sent to the controller on the stretch press. Thus the operator,
when forming the part, directly used the FEA information. By developing the tooling dies and the manufacturing controls in a
virtual manner, the risk associated with part manufacture and assembly was reduced.
8. TYPES OF BASIC MANUFACTURING
SIMULATIONS IN VIRTUAL MANUFACTURING
CASTING SIMULATION
COMPOSITE
SIMULATION
FORMING SIMULATION
WELDING AND
ASSEMBLY SIMULATION
15. ADVANTAGES OF WELDING SIMULATION
Minimize the
cost of
prototyping,
Minimize the
cost of
distortion repair
work,
Develop and
optimize a weld
plan within the
shortest time
range,
Keep welding
distortion
within
allowable
tolerances,
Guarantee the
best weld
quality,
Control stresses
in welded
designs.
