Top 9 takeaways from IABC 2021

1. Less car OEM management = speed to market
2. EV models are safer than their ICE counterparts
3. IIHS’s Side Impact 2.0 defined and contextualized
4. Extreme size BIW components are here
5. Digital twins speed BIW validation process
6. Quick math for lateral crush strength of thin-wall automotive structures
7. How to get impressive gains in BIW metrics: 2022 Honda MDX
8. Adapting the Ford C2 platform for a unibody truck: 2022 Ford Maverick
9. Optimized energy absorption: 2021 Nissan Rogue
   
   

IABC Takeaway #1

Ford develops 2022 Maverick 20 months faster using less management

The 2022 Ford Maverick was developed 20 months faster than any other car in Ford’s history. Ford’s Jim Baumbick, Vice President, Enterprise Product Life Management, explains:

"…the little-known story is we skipped 95% of the senior leadership forums, the traditional forms that we use for product approvals. And we created an environment where the leadership basically showed up [only once] every week.

Every Friday there was a two-hour opportunity, and if a leader needed to interact or wanted a status, they could show up at that time and kind of get an update. But more importantly, the agenda was set by the [development] team of what they needed for help from the leadership team to actually get to the ultimate goal [of developing a car 25 months faster than ever before]."

The Maverick starts at $19,995 MSRP(!).

IABC Takeaway #2

EV models are safer than their ICE counterparts

David Zuby of the Insurance Institute for Highway Safety-Highway Loss Data Institute (IIHS-HLDI) told how electric vehicles (EVs), when compared to their same name-plate ICE counterparts, have:

1. Lower insurance claim frequencies.
2. Cost about the same to repair as ICE models.
3. Have 22% lower bodily injury claims.
4. Have 40% lower claims for personal injury protection (aka “no fault” insurance).
5. Have 41% lower medical insurance payments.

IHS-HLDI’s conclusion: EVs should cost less to insure than their ICE counterparts.

However, EVs cause more damage to other vehicles during impact, probably because of their higher (battery) weights. [SSAB ponders how car designers will solve this challenge in future EV designs.]

Zuby continued: the Chevrolet Bolt, Nissan Leaf, and Tesla Models 3 and 4, when compared to other ICE cars in their segments (and not just their name-plate counterparts, if even applicable) do very favorably. Fatalities for the Leaf, which has been on the market for a long enough time to gather statistically meaningful data, are low compared to ICE cars in their segment.

And there is no significant difference between EVs and their ICE counterparts for non-crash fires. Currently, there are not enough data to draw conclusions regarding post-crash fires and fatalities for EVs: the number of post-crash fire fatalities (where the fire was the single most harmful event) are in the single digits for EVs.

IABC Takeaway #3

Side Impact 2.0 test: OEMs eager to rate highly

Becky Mueller outlined the most significant changes from Side Impact 1.0 to 2.0 testing, where IIHS-HLDI is trying to match the size and shape of a mid-sized SUV — something like a Ford Explorer. The 2.0 test:

1. Increases from 50 km/h to 60 km/h for the perpendicular impact from the Movable Deformable Barrier (MDB), aka “crash cart.”
2. Increases the MDB weight to 1900 kg to reflect the higher number of SUVs and truck-up trucks driving today. Together, the speed and weight changes mean the new IIHS’s Side Impact 2.0 test delivers 82% more energy than their 1.0 test.
3. Adding suspension to the MDB for more consistent rolling (i.e., reduce bouncing).
4. Updates to the 20-year-old barrier face on the MDB to reflect today’s SUV and truck-up truck designs, with lower overall height, thicker barrier, and changes to barrier stiffness.

The IIHS-HLDI has found that maximum B-pillar intrusion is a highly effective estimator of fatalities — and that that reducing the intrusion by 20 cm lowers deaths by 25%.

IIHS-HLDI’s initial Side Impact 2.0 testing of 15 small SUVs provided a range of results: from just three centimeters (B-pillar to dummy centerline; i.e., not good) to 23 cm, considered “exceptional” (“good” being beyond what is needed for the survival space of a small female dummy).

The less the amount of side impact intrusion of the B-pillar, the better the chances of survival — with the distance to the occupant’s pelvis being a key metric. Images courtesy of Insurance Institute for Highway Safety-Highway Loss Data Institute, Arlington, Virginia, USA www.iihs.org.

Furthermore, while current small SUV designs did well protecting the head and upper torso, the lower torso and pelvic remain vulnerable in some models as determined in the Side Impact 2.0 test, calling for countermeasures in BIW safety designs.

Higher percentage of Good Boundary (right sides of charts) means reduced chance of injuries. “HIC” stands for Heat Injury Criterion. Charts courtesy of Insurance Institute for Highway Safety-Highway Loss Data Institute, Arlington, Virginia, USA www.iihs.org.

As previously reported by the IIHS-HLDI, doors seem to experience higher deformation in the 2.0 testing. The IIHS-HLDI is on schedule to use the new Side Impact 2.0 Test for their Top Safety Pick 2023.

IABC Takeaway #4

New “extreme size” BIW components simplify car tooling and assembly

Speaking of doors, Gestamp has some bold new approaches to making what they call “overlap patch blank hot-stamped door rings,” reports Paul Belanger. This is a continuation of their Extreme Size BIW products, which now includes single door rings, one-piece floors, and ring frames.

The “extreme” goals for the door rings are to reduce the number of BIW parts, simplify production and assembly, reduce costs, increase safety, and reduce CO₂ emissions. For their optimized door rings, developed to meet increasing safety requirements, Gestamp has integrated eight parts into one press-hardened steel (PHS) part using extreme size tooling.

With this new technology solution, Gestamp offers an all-new alternative to the market using simple resistance spot welding blanks — by overlapping the RSW blanks. Gestamp’s new serial production lines do not require ablation but instead use in-house spot welding, providing easy adjustment to both the blank and weld as needed. The maximally integrated door ring design is cost effective while improving stiffness in key areas.

Gestamp’s Overlap Patch Solution eliminates the need for ablation, simplifying the welding process. Patches can be engineered to increase stiffness in critical locations. Images courtesy of Gestamp.

IABC Takeaway #5

“Virtual Assembly References” speed BIW validation process

Imagine a digital body-in-white assembly method that validates your processes, while predicting and preventing problems typically not discovered until after physical parts have arrived. That’s how Todd McClanahan described AutoForm Assembly’s use of a Virtual Assembly Reference — what others might call a digital twin.

The Virtual Assembly Reference, or VAR, drives the assembly to its intended nominal accuracy. Finding these new target geometries — early in the engineering phase of a project — allows manufacturers to eliminate multiple iterations of tool modifications, saving time and costs.VAR improves engineers’ understanding of the relationship between single parts and the entire assembly, generating new target geometries for components as part of an effective design compensation strategy. The goal is fewer component modifications late in development, reducing tooling and equipment costs, while getting to “high maturity” and robustness earlier —ultimately reducing lead times.

IABC Takeaway #6

Quick assessment equation for thin-wall automotive structures

Ford and Altair Engineering jointly presented a new equation for quickly estimating the lateral crush strength of multi-cell thin-wall structures when subjected to 3-point bending load. Their goal was to create a useful tool for the quick assessment of different design configurations.

The equation is based on the basic structural mechanics principle of thin-plate buckling – supplemented with empirical factors to represent the geometric constraints of thin-wall multi-cell constructions. The semi-empirical equation for predicting the peak lateral crush strength of thin-wall sections has been verified with data collected from physical testing and finite element simulation models.

IABC Takeaway #7

2022 Honda MDX: impressive gains in BIW metrics

In a theme repeated by all the car OEMs at IABC 2021, Honda is targeting top collision ratings through a combination of innovative BIW design and higher strength materials. For overall materials, its 2022 MDX redesign features 60.9% high strength steel and 8.8% aluminum, helping MDX to achieve:

• 68% increase in upper load path axial crush
• 29% increase in subframe load path-controlled bending
• 34% increase in side sill load capacity
• And a 10% increase in A-pillar load capacity

A new 1.0 mm 780T MPa AHSS steel for the lower dash saves 3.3 kg (replacing the previous 1.2 mm 590Y panel) while reducing crash intrusion into the passenger cabin.

New door intrusion beams orientated to distribute loads to pillars and side sills increase energy absorption from side impacts. The beams overlap with the body structure, transferring the load directly to the body, low on the structure. As a result, B-pillar intrusion into the cabin is reduced by 34%.

The 2022 MDX has a 4-piece door ring featuring tailor laser-welding of 1500 MPa press-hardened steel (PHS). Twenty-three meters of high-performance structural adhesive is used for improved body stiffness. (Another IABC presenter, Henkel, reported extensive test data on welded vs. weld/adhesive-bonded vehicles, demonstrating improved body stiffness and energy absorption in metal structures while also increasing fatigue durability.) All these body rigidity efforts resulted in MDX having a 32% improvement in global torsional rigidity, for improved handling response, NVH, and ride comfort.

IABC Takeaway #8

2022 Ford Maverick: adapting the C2 platform for a unibody truck

In addition to its speedy development, the 2022 Ford Maverick pick-up truck presents lots of new body design innovations.

To begin with, Ford used its existing C2 platform as much as possible. But its all-new Maverick unibody truck box rear floor meant new designs to its rear rail architecture, bridging kick-up and side sill extensions, flat box load floor, rear sill reinforcement, and D-pillar reinforcement for tailgate aperture.

The transition between the Maverick’s truck box and cab is more extreme than the rail transition seen on a typical unibody. The new “rail-in-rail” design splits the rail into two stampings to: 1) allow for the required depth of the rail, 2) improve the stability of the section, and 3) optimize the joint between the rear rail and the cab rear sill. The top half of the Maverick box and cab integration resulted in a flow-through of the box top rail’s inner and outer into the C-pillar structure.

The 2022 Ford Maverick is a global vehicle, able to meet safety standards throughout the world.

Ultra-high strength steel was used strategically in combination with a variety of other materials to protect the passenger compartment through both material strength and crash energy management. Ford notes that over the years frontal crash requirements have evolved into severe and complex modes — driving the need to develop front ends that can efficiently handle crash loads in multi directions.

In response, Ford developed its Three-Dimensional Load Path (3DLP) Strategy to utilize front-end subsystems (shotguns, rails, subframe) to manage crash energy in various overlaps — vertically and across the front end. 3DPL uses crash-pulse optimization through the timely deployment of structural subsystems, coupling all front-end subsystems for better energy management in all directions.

IABC Takeaway #9

2021 Nissan Rogue: optimized energy absorption

The 2021 Nissan Rogue achieves a total reduction of 5% in its drag coefficients (Cd), credited in part to its air curtains (a segment first, -1% Cd), 3D tire deflectors (-5% Cd), active grille shutter, underbody covers, optimized rear end (rear spoiler/lamp combination), and optimized A-pillar shape.

The 2021 Rogue’ passive safety design leverages UHSS, with expanded use of hot-stamped boron steel to balance mass as well as emissions and safety requirements. Multiple load paths in its floor beams help transfer impact forces away from occupants. Rogue also features a smoothly connected new platform for better axial load distribution, providing optimized energy absorption. Rogue’s energy-absorbing fender and hood structure mitigates pedestrian head impact, while an energy-absorption pad reduces lower leg impacts.

Key conclusions from 2021 International Automotive Body Congress

1. The use of HS, AHSS, and UHSS steels continues to increase in new body-in-white designs.
2. Hot-stamped (PHS) steels appear to be increasing in BIW use.
3. IIHS’s Side Impact 2.0 Test will require some design countermeasures in some vehicles to reduce B-pillar intrusion and high door deformation.
4. EVs on the road now are safer than then their plate-name counterparts and should also cost less to insure.