Info

HDA is a design & development firm specializing in reinforced composite materials. We bring innovative COST SAVING solutions to your product line through the use of plastic and composite materials.

We create cost-saving designs based on our extensive experience in materials, design, structural analysis, and cost estimation.

We cost reduce your product by:

1. Providing several design alternatives to an existing product.
2. Assessing costs of each alternative to validate cost feasibility.
3. Analyzing the preferred concept to validate functional requirements.
4. Assisting in the prototype, testing, troubleshooting, and launch of your redesign.

Design

Design and Development Services:

Howarth Development Associates is able to provide you with original design concepts for a new component or to redesign your part for manufacture in an alternative material. We can help you discriminate between several designs using cost models and finite element analysis. Because of our extensive plastics experience, we can discriminate between a design which is adequate, and one which will meet your requirements and provide optimum processability. We know tooling and are able to provide direction in proper part layout and help you avoid unnecessary tooling complications.

We use a Windows-based solid modeling package called SolidWorks, which is able to import a variety of file types. We find that ACIS, Parasolid, and STEP are excellent transition formats and are virtually infallible. IGES data is usually good but can be troublesome if it originates in older modeling packages. Once imported, we can manipulate your model to provide necessary design alterations to make a design suitable for alternate materials or a design improvement.

This is a thermoplastic composite wheel we designed with Hiper Technology.

 

Metal Replacement

Metal Replacement Overview:

The biggest incentive for metal replacement with polymers is cost. Many people unfamiliar with structural plastics view these materials as being “cheap”. In reality, the plastic materials which are truly structural in nature actually cost more per pound than the metals that they are replacing.


Given this fact, the question, “WHY PLASTICS?” is logical and requires some exploration. In order for structural composites to compete with metals in a particular application, there must be some cost incentive in the larger picture. When high volume purchases of steel can be made for $0.26/lb, and unfinished aluminum die castings bought for $2.00/lb, when do plastics make sense?
The answers vary greatly across industries, but the following statements hold true.

 

To “parts consolidate,” or integrate several components into a single molded part:

The elimination of labor and process costs associated with joining or assembling several components is a very important consideration in the decision to use plastics. Aside from labor and process costs, one hidden cost that many overlooks are scrap. For example, if one assembles two parts costing one dollar each and encounters a bad weld, the total value of the scrap is two dollars, PLUS the cost of the weld and inspection. Although this is a simple example, it illustrates the potential cost savings associated with parts integration, regardless of material

Howarth Development Associates can identify cost-saving applications for plastics and composites in your product line.
We are very experienced in metal to plastic translations, and can provide 
design concepts and validate structural integrity of components which provide a cost incentive to replace metals.
We keep current on all new fiber and resin developments, including carbon, glass, and aramid fibers, as well as high temperature materials.

When secondary operations, such as machining, tapping, or welding are required:

Perhaps the most significant advantage to injection molded materials is the ability to form “net shape” components. This means that after the part is molded and de-gated, no other work is required to make that part functionally complete. With proper tool layout and part design, it is possible to incorporate a variety of features into the component which might need to be done as a secondary operation in other manufacturing processes.

To achieve chemical or corrosion resistance without the need for painting or coating:

This is one of the largest reasons that composite materials continue to replace metals in the automotive industry. Salt spray tests, which are required for all underhood and chassis components, are extremely demanding on steel, aluminum, and magnesium brackets, etc. To prevent corrosion of metal components, a protective coating must be added, which increases part cost.

To reduce weight, while maintaining component performance for “extreme” applications:

Composite materials are known for their high specific strength and stiffness (strength and stiffness per weight). The need to reduce weight becomes extremely important for applications of mobility where weight creates a recurring cost penalty. Commercial aircraft, for example, fly for twenty to thirty years. An aircraft which is overweight will consume more fuel and have less carrying capacity (fewer seats sold) than a more efficient design. Compounded over the life of a plane, these costs easily justify the increase in purchase price of a plane with more advanced (and more expensive) materials. Note that the extreme applications are generally performance (not cost) driven, and have a greater emphasis on performance.

 

Structural Analysis

Structural Finite Element Analysis (SFEA) is a method by which the structural response of a component is simulated. FEA CAN:

Provide validation of the structural performance of a component. Allow several iterations of design to be ‘tested’ in advance of tooling Help to optimize a part by minimizing material usage.

In the case of metal to plastic translations, the SFEA is of critical importance.

Results from the target component are used to:
Help define geometry
Select candidate materials
Establish realistic performance goals
The process itself starts with a predefined geometry. The part is then “meshed,” or broken into a series of smaller pieces, which represent the geometry. After loads and constraints are applied and material properties defined, the problem is solved

Creating and running the model is only the beginning. The most important aspect of a structural FEA is the interpretation of results and using this information to develop improved designs. As a customer, you get maximum value out of an analysis when questions other than “Will it fail?” are answered.

You Should expect these questions to be answered as well:

If the part fails, what is the best way to reinforce it? 
Is there an opportunity to “cost reduce” this part by removing material?
Based on the results, is there a more “material efficient” design that will achieve the same performance? 
Can we substitute a lower cost material for the existing material?

Depending on the type of results required, there are several different types of analysis runs:

Linear Static Analysis :

This is the fastest and most common analysis run. It simulates the structural response of the component under prescribed loading at equilibrium. Linear analysis is accurate within its realm; large deflections and nonlinear materials cannot be modeled accurately.

Non-Linear Static Analysis:
Non-linear static analysis simulates the structural performance of a static load case involving either or both of the following:
1. Large part deflections
2.Materials which do not have a constant stiffness with increasing strain
3. Contact Analysis
These analyses are more time-intensive, both in terms of creating the model and solving time. Using a planar element rather than a solid will save solving time, but will likely require additional time in creating the model. It is generally wise to start with a linear analysis to verify the need for a non-linear analysis.
Mode Shape Analysis :
This analysis predicts the natural frequencies of the part and the mode shapes associated with each frequency. These results are very important in the automotive industry, where the elimination of noise/vibration/harmonics leads to a quieter ride. In other industries, it is used to identify the frequency at which a component will vibrate excessively, often with catastrophic results.

On-Site Seminars

On-Site Seminars

We can teach your technical staff what they need to know about thermoplastics. Below are example slides from a 110-slide “Intro to Thermoplastics” seminar. We have presented this seminar dozens of times, with overwhelmingly positive feedback.

Topics covered in this workshop include:

Why use thermoplastics?
Types & properties of thermoplastics 
Proper design of thermoplastics
Engineering properties of thermoplastics
Fiber orientation and mechanical properties
Long-term properties 
Effects of fillers, additives, and reinforcements
Assembly techniques
Introduction to tooling 
Introduction to injection molding

Example Slides:

Classes of Thermoplastics :

Mechanical Property Tradeoffs with Compounded:

Proper Geometry:

Fiber Orientation Effects on Mechanical:

Stress Relaxation in Thermoplastics: