Lightweighting

The philosophy of Lightweighting stems from regulatory and other pressures to improve fuel efficiency, increase performance and reduce greenhouse gases. The Lightweighting approach applies to all sectors including, automotive, aerospace, maritime, offshore and rail.

Vehicles with lower inherent mass have lower inertia, can respond or accelerate quicker. Higher payloads can be offered for the same operating cost.

There are significant cascade effects by reducing the primary mass, as the mass of any supportive structures can also be reduced. The reduction effect is also felt on emissions, lower fuel cost, lower capital cost, lower operational cost and transportation cost. 

Lightweighting techniques also include the need to reduce Stress Concentrations (Kt) in a product. Because frequently, when designers attempt to reduce high stress concentrations the weight of a product is increased.

Stress concentrations have been shown to encourage surface crack propagation and dictate the probability of fracture occurrence. High stress concentrations, promotes early component failure initiating at the surface of the component. ​90% of crack initiation flaws begin at surface locations and propagate in regions of stress concentrations. 

​A key factor in product life enhancement is the need to reduce stress concentrations. The minimisation of stress concentrations or ideally, elimination of stress concentrations will result in a longer product life.

​Many Designers and Engineers to reduce stress concentrations, will apply a circular fillet and increase the radius of the fillet in an attempt to reduce the stress concentration. However, increasing the circular fillet radius is not consistent with minimum stress concentration. There exists an optimum circular fillet radius (based on part geometric ratios and loadcase) above or below which will generate a higher value of stress concentration and unnecessarily increase component WEIGHT (Tranxuan, 1994). 

Therefore, its important to be aware of and use the techniques to reduce or even eliminate stress concentrations if you want to obtain a low weight, strong and long life product.

 The following content is covered in this course:

Fillet-Based Solutions

• Conventional techniques for stress concentration reduction under a single loadcase 
• Advanced techniques for stress concentration reduction under a single loadcase
• Optimum stress concentration reduction techniques under a single loadcase
• Advanced stress concentration reduction techniques under multi-axial loadcase

Fillet-Free Solutions

• ​Advanced stress concentration reduction techniques under a combined loadcase
• Advanced stress concentration elimination techniques under a single loadcase
• Advanced stress concentration elimination techniques for all independently applied loadcases
• Advanced stress concentration elimination techniques under single and combined
• Simple technique to eliminate stress concentrations for any geometric aspect ratio
• How to invert the stress distribution in the fillet region, i.e. remove the high stress

This course includes a 1 month license for PROFILE - a stress concentration elimination software.