As an engineer, it is very important to understand the strength-to-weight ratio. Because when incorporating different materials into applications, engineers must be able to accurately evaluate and analyze various properties of materials. The most important of these is the weight and strength of the material. This is because the strength and weight of materials will affect the load-carrying capacity and efficiency of the design. As well as, the appropriate strength-to-weight ratio can also help engineers save material costs without sacrificing the high-level performance of the product.
How to deeply understand the strength-to-weight ratio? Don’t worry, this article will introduce you to the importance, and the affect factors of the strength-to-weight ratio, and how to apply them to help you to be handier in design.
What is the strength-to-weight ratio?
The strength-to-weight ratio is literally the ratio between the strength and weight of a material, calculated as the strength of the material divided by its surface density. It should be noted that the optimal ratio is based on different applications of materials, not a specific ratio. Here, we also list the strength-to-weight ratio of some common materials, so that you can better understand the gap between the strength-to-weight ratio of different materials. At the same time, the tensile strength, density, and breaking length of different materials are also listed.
| Material | Tensile Strength (MPa) | Density(g/cm³) | Strength to Weight Ratio(N·m/kg) | Breaking Strength(km) |
| Concrete | 2–5 | 2.30 | 5.22 | 0.44 |
| Natural Rubber | 15 | 0.92 | 16.3 | 1.66 |
| Copper | 220 | 8.92 | 24.7 | 2.51 |
| Nylon | 78 | 1.13 | 69.0 | 7.04 |
| Aluminum Alloy | 572 | 2.81 | 204 | 20.8 |
| Stainless Steel | 505 | 8.00 | 63.1 | 6.4 |
| Kvela | 3620 | 1.44 | 2514 | 256 |
| Chailon | 5800 | 1.54 | 3766 | 384 |
| Colossal carbon tube | 6900 | 0.116 | 59483 | 6066 |
Why is the strength-to-weight ratio important to engineers?
Strength-to-weight ratio is often an important factor for engineers to consider. That’s because the strength-to-weight ratio helps engineers determine the weight of a material or part and compare a material to its performance in a given application.
At the same time, engineers can optimize ratios to improve efficiency and performance and save costs associated with materials required for application-specific strength. This means you can achieve strength-to-weight ratios in any project where the materials used are tailored to the needs of the project while reducing costs and increasing performance.
What factors affect the strength-to-weight ratio?
Of course, as you might expect, the strength-to-weight ratio is influenced by many factors. Among them, different materials and components are one of the most important factors affecting the strength-important ratio. For example, common metals, plastics, composite materials, etc. There will have different effects on strength-to-weight radio according to different elastic modulus, yield stress, ultimate tensile strength, and strain hardening rate.
Due to its high strength-to-weight ratio, metal is the most commonly used material in many engineering projects. Plastics tend to have a lower strength-to-weight ratio than metals and are more susceptible to damage from UV exposure. In addition, composite materials and carbon fiber are also relatively light materials, provide excellent strength and durability, and are also one of the more commonly used materials in engineering projects.
Some people may have such a question, why is there no mention of wood? Because wood is also one of the materials that often appear in many projects. This is because wood, although it can provide good strength at a relatively lightweight, tends to warp and shrink relatively easily.
How to apply the strength-to-weight ratio?
Now, you can learn how to apply different strength-to-weight ratios in engineering projects so that you can complete your designs with excellence.
As you should know earlier, the strength-to-weight ratio is a very important reference factor for the selection of engineering materials. Different materials have different strength-to-weight ratios. For example, in the automotive and aerospace sectors, a very strong material is required with as little mass (or weight) as possible. And in order to make it more portable and durable in our daily use. Therefore, materials such as aluminum, titanium, and magnesium are usually selected in engineering and manufacturing projects in the automotive and aerospace fields, because of their high strength-to-weight ratio. If mass is not a huge concern, then steel can be chosen to achieve the same strength, but at the expense of weight. But there is a thing worth noting that the cost of such materials is usually relatively high.
Therefore, although the strength-to-weight ratio is one of the important factors in the selection of materials, it is not an absolute influencing factor. When choosing materials, we still need to consider several issues:
- How much is the cost of the raw material?
- Does the corrosion resistance meet the needs of the project?
- Does the corrosion resistance meet the needs of the project?
- Is the manufacturing process simple or complex? Is it possible to achieve a large supply?
These are issues that engineers need to consider clearly when designing and selecting materials. As you know, coming up with a great design is no easy feat!
Conclusion:
After reading this article, you will discover that the strength-to-weight ratio is a significant factor in engineering projects and a ratio that engineers will often use. But at the same time, we clearly know that it is not easy to complete an excellent design. If you are still confused about how to get a design you are satisfied with, you may wish to seek the help of CNCMass, which has expert support in CNC Machining, to make everything easier!
