How should growing demand from consumers for their right to repair – to fix products themselves – influence manufacturers’ decisions around product design and materials choices, asks Craig Hillman, director of software development at Ansys?
Advocates of the ‘right to repair’ movement look back favourably on a time when consumers were able to take a do-it-yourself approach to fixing everyday machinery, such as automobiles, washing machines or refrigerators – or could at least call in a qualified thirdparty repair company, instead of relying on the original equipment manufacturer (OEM).
Farmers who have been used to repairing their own tractors, for example, resent the fact they are voiding their warranty if they don’t load the tractor onto a flatbed truck and pay to haul it hundreds of miles to the manufacturer’s facilities, for repairs that will likely cost more than if they had performed them themselves.
Mobile phone owners might prefer to have instructions on how to replace a battery, rather than paying the inflated prices of a manufacturer’s repair service.
And environmentalists lament overflowing landfills, containing products that are trashed rather than repaired, as well as the excess energy consumed and greenhouse gases emitted in manufacturing their replacements.
For their part, OEMs cite intellectual property rights that could be at risk if they are made to publish schematics of the inner workings of their proprietary designs. They say that do-it-yourselfers could injure themselves or further damage products if they do not have the necessary skills to make repairs.
They also warn that third-party replacement components might not meet their own quality standards. And obviously, the loss of revenue that might result from making their products easy to repair is another concern.
This ‘right to repair’ movement is particularly noticeable in the US. Starting with the first Motor Vehicle Owners’ Right to Repair Act, passed in Massachusetts in 2012, the movement has spread, with 20 US states considering similar legislation in 2019. As expected, some OEMs are defending their rights and lobbying legislators to prevent passage of these laws.
Recently, the European Union (EU) passed its own right to repair legislation for major appliances, including washing machines, refrigerators, lighting and dishwashers. This means that starting in 2021, EU businesses that sell these products must make them easily repairable with common tools and provide spare parts for up to 10 years after the last unit is sold. The EU is also contemplating including consumer electronics like TVs, computers and mobile phones in future laws.
So what might be the impact of this kind of legislation on product design? In fact, some corporations are already changing the way they design mechanical and electronic products and how they choose materials for each component. Their experiences can provide key insights into how other manufacturers will eventually need to change their overall design strategies.
Design decisions on mechanical parts such as connectors, seals and enclosures are among the first to be revised. Permanent attachments, such as welds or glued joints, are being replaced with separable connections, such as latches or gaskets. Even separable connectors are being redesigned to be more accessible.
For instance, some corporations are starting to ensure that the force required to insert and remove connectors follows best-in-class human ergonomics. Modelling and simulation software will play an increasing role in understanding the repairability of these products.
Role of simulation
At Ansys, we’ve seen how our product Ansys Mechanical can perform mechanical simulations of connectors to gain insights into the effects of extended repairability, as well as knowledge of the forces required to disengage connectors. Design teams can use Mechanical to ensure that the force required to disengage connectors is practical, given the location of the connector within the system.
For example, the average key pinch (easy-to-access) and tip pinch (hard-to-access) connectors can differ in strength by up to 45N (or 10 pounds of force).
Mechanical can also predict the number of insertions before a connector fails. Each insertion and removal introduces stresses that can induce low-cycle fatigue in the part’s polymer constituents. Design teams have typically assumed that the part will need to survive one to five insertions. However, with the right to repair, these connectors could see 10 times the number of insertions and removals.
For gaskets and other polymer-based components that will become brittle with age, simulations in Mechanical can answer the question, “How brittle is too brittle?”
By modelling stresses on the gasket seal mechanism, engineers can determine whether it will still be viable in 10 years, or if a change in materials will be required. Having to consider materials that will be able to retain their form and function after 10 years of use and storage presents OEMs with two key challenges.
First, the necessary lifetime of certain parts may now double (assuming 10 years in storage awaiting need for repair and 10 years in the field). Typically, this is not a risk for metal structures, because warehouse environments are more benign than field applications. However, extended storage can be an issue for connections, plastic parts and electronic hardware due to oxidation, plasticiser evaporation and other processes.
The second challenge is that the legislation may entice the consumer to expect the field lifetime to also be longer. Take Max Mustermann, a German homeowner who buys a brand-new washing machine: before the legislation, Max would likely expect the machine to last as long as the warranty. If the warranty is 10 years, then Max will plan on buying a new machine the first time it breaks down outside of the warranty period.
Now, with the right to repair, Max will hold on to the machine far past the warranty period and will still expect the machine to operate reliably. That is to say, he may be okay with a repair every few years, but it should not fail more often than that.
To meet this new expectation of lifetime, OEMs will need to improve the robustness of all aspects of the machine (latches, seals, paint, motors, electronics, displays and so on). The combined effects of these two challenges could potentially double or triple current product lifetimes.
The risk mitigation of right to repair
The effect of legislation on electronics will depend on whether OEMs view the minimum field-repairable unit as an electronic part (CPU, electrolytic capacitor, relay, and so on); a printed circuit board assembly (PCBA); or the entire box or enclosure.
Repair at the part level will require printed circuit boards (PCBs) to withstand multiple heat exposures during repair processes. Most companies qualify PCBs to withstand four exposures to assembly temperatures (around 245°C or 473°F) during primary reflow, secondary reflow, wave and one rework.
Each repair attempt will require two additional exposures to these temperatures to remove and attach parts. This means that if design teams need products to withstand at least two repairs, the number of heat exposures will double from four to eight. This is a difficult requirement for PCBs and the introduction of unseen physical damage is a real risk.
OEMs will either need to eliminate part-level repair or reevaluate design robustness. Costly physical tests have been the typical evaluation approach; however, Ansys Sherlock or Ansys Mechanical can affordably simulate the reflow process to determine if, for example, internal vias will delaminate or crack due to additional stresses.
OEMs will also be challenged to extend the storage and lifetimes of electronic hardware, because several components – including relays, connectors, electrolytic capacitors and solder joints – can have limited lifetimes. Relays and connectors can oxidise, leading to greater electrical resistance. The fluid in electrolytic capacitors attacks the oxide that provides the capacitance, dissolving into the liquid electrolyte over time; the electrolyte can also evaporate while the capacitor sits on the shelf.
Regarding solder joints, the physics behind solder fatigue has been well-studied and the most validated failure models have been incorporated into Ansys Sherlock. A wide range of complex storage and use environments can be input into the models to produce reliability predictions.
If manufacturers are going to succeed, while also cooperating with the right to repair movement building in multiple countries, they will need to implement solutions now. While the timeline for implementation will vary, multinational corporations will need to update design and validation processes to follow existing EU legislation. They also need to prepare for possible passage of similar legislation with different details in the US and other countries.
Multiple technical challenges around compliance – such as traditional development approaches and physical prototyping and testing – could cause design and validation costs to balloon. Simulation can perform these tasks quickly and virtually, enabling manufacturers to stay ahead of the right to repair curve in a cost effective manner.